Lack of prognostic impact of sentinel node micro-metastases in endocrine receptor-positive early breast cancer: results from a large multicenter cohort☆

Background

Prognostic impact of lymph node micro-metastases (pN1mi) has been discordantly reported in the literature. The need to clarify this point for decision-making regarding adjuvant therapy, particularly for patients with endocrine receptor (ER)-positive status and HER2-negative tumors, is further reinforced by the generalization of gene expression signatures using pN status in their recommendation algorithm.

Patients and methods

We retrospectively analyzed 13 773 patients treated for ER-positive breast cancer in 13 French cancer centers from 1999 to 2014. Five categories of axillary lymph node (LN) status were defined: negative LN (pN0i−), isolated tumor cells [pN0(i+)], pN1mi, and pN1 divided into single (pN1 = 1) and multiple (pN1 > 1) macro-metastases (>2 mm). The effect of LN micro-metastases on outcomes was investigated both in the entire cohort of patients and in clinically relevant subgroups according to tumor subtypes. Propensity-score-based matching was used to balance differences in known prognostic variables associated with pN status.

Results

As determined by sentinel LN biopsy, 9427 patients were pN0 (68.4%), 546 pN0(i+) (4.0%), 1446 pN1mi (10.5%) and 2354 pN1 with macro-metastases (17.1%). With a median follow-up of 61.25 months, pN1 status, but not pN1mi, significantly impacted overall survival (OS), disease-free survival (DFS), metastasis-free survival (MFS), and breast-cancer-specific survival. In the subgroup of patients with known tumor subtype, pN1 = 1, as pN1 > 1, but not pN1mi, had a significant prognostic impact on OS. DFS and MFS were only impacted by pN1 > 1. Similar results were observed in the subgroup of patients with luminal A-like tumors (n = 7101). In the matched population analysis, pN1macro, but not pN1mi, had a statistically significant negative impact on MFS and OS.

Conclusion

LN micro-metastases have no detectable prognostic impact and should not be considered as a determining factor in indicating adjuvant chemotherapy. The evaluation of the risk of recurrence using second-generation signatures should be calculated considering micro-metastases as pN0.

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LN micro-metastases have no detectable prognostic impact.

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pN1 status, but not pN1mi, significantly impacted overall survival, disease-free survival, metastasis-free survival.

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In the subgroup of patients with known tumor subtype, pN1=1, as pN1>1, but not pN1mi, had a significant prognostic impact on OS.

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LN micro-metastases should not be considered as a determining factor in indicating adjuvant chemotherapy.

The CINSARC signature predicts the clinical outcome in patients with Luminal B breast cancer

CINSARC, a multigene expression signature originally developed in sarcomas, was shown to have prognostic impact in various cancers. We tested the prognostic value for disease-free survival (DFS) of CINSARC in a series of 6035 early-stage invasive primary breast cancers. CINSARC had independent prognostic value in the Luminal B subtype and not in the other subtypes. In Luminal B patients receiving adjuvant endocrine therapy but no chemotherapy, CINSARC identified patients with different 5-year DFS (90% [95%CI 86-95] in low-risk vs. 79% [95%CI 75-84] in high-risk, p = 1.04E-02). Luminal B CINSARC high-risk tumors were predicted to be less sensitive to endocrine therapy and CDK4/6 inhibitors, but more vulnerable to homologous recombination targeting and immunotherapy. We concluded that CINSARC adds prognostic information to that of clinicopathological features in Luminal B breast cancers, which might improve patients' stratification and better orient adjuvant treatment. Moreover, it identifies potential therapeutic avenues in this aggressive molecular subtype.

Dosimetric characterization of a small-scale (Zn,Cd)S:Ag inorganic scintillating detector to be used in radiotherapy

PURPOSE

In modern radiotherapy techniques, to ensure an accurate beam modeling process, dosimeters with high accuracy and spatial resolution are required. Therefore, this work aims to propose a simple, robust, and a small-scale fiber-integrated X-ray inorganic detector and investigate the dosimetric characteristics used in radiotherapy.

METHODS

The detector is based on red-emitting silver-activated zinc-cadmium sulfide (Zn,Cd)S:Ag nanoclusters and the proposed system has been tested under 6 MV photons with standard dose rate used in the patient treatment protocol. The article presents the performances of the detector in terms of dose linearity, repeatability, reproducibility, percentage depth dose distribution, and field output factor. A comparative study is shown using a microdiamond dosimeter and considering data from recent literature.

RESULTS

We accurately measured a small field beam profile of 0.5 × 0.5 cm² at a spatial resolution of 100 µm using a LINAC system. The dose linearity at 400 MU/min has shown less than 0.53% and 1.10% deviations from perfect linearity for the regular and smallest field. Percentage depth dose measurement agrees with microdiamond measurements within 1.30% and 2.94%, respectively for regular to small field beams. Besides, the stem effect analysis shows a negligible contribution in the measurements for fields smaller than 3x3 cm². This study highlights the drastic decrease of the convolution effect using a point-like detector, especially in small dimension beam characterization. Field output factor has shown a good agreement while comparing it with the microdiamond dosimeter.

CONCLUSION

All the results presented here anticipated that the developed detector can accurately measure delivered dose to the region of interest, claim accurate depth dose distribution hence it can be a suitable candidate for beam characterization and quality assurance of LINAC system.

Eribulin Efficacy on Brain Metastases in Heavily Pretreated Patients with Metastatic Breast Cancer

The onset of brain metastases (BM) is a major turning point during advanced breast cancer (ABC) evolution, with only few treatment options when local therapies have failed. The therapeutic effect of eribulin, a wildly used drug in the treatment of ABC, remains unclear in this setting. Patients and Methods: We performed a retrospective observational study to assess eribulin efficacy in patients with ABC who displayed BM at time of eribulin initiation. We collected data from the medical files of all ABC patients who received eribulin at our institution from 2012 until 2020. Our main endpoint was the central nervous system (CNS) progression-free survival. (CNS-PFS). Other evaluation criteria were extra-cranial progression free survival (PFS) and overall survival (OS). Results: Twenty patients with BM monitoring data available were selected out of the 549 who received eribulin during the inclusion period. Fifteen patients (75%) had BM progressive as the best response, three patients (15%) had disease stabilization for more than 6 months and only one patient had a partial response according to RECIST 1.1 criteria. Median CNS-PFS was 3.39 months (95CI (3.02–3.76)). Cox univariate analysis identified molecular subtype as the only prognostic parameter in our cohort, with patients with hormone-receptor positive tumors less likely to experience CNS progression than those with triple-negative MBC (HR = 0.23 (95CI = 0.07–0.80), p = 0.021). Median extra-cranial PFS was 2.67 months (95CI (2.33–3.01)). Median OS was 7.68 months (95CI (0–17.41)). Conclusion: Eribulin seems to have only a limited impact on BM evolution. Hormone receptors expression may identify a subset of patients with better BM control.

Advance Approval of Outpatient Chemotherapy via Phone Call Optimizes Healthcare Delivery without Compromising Patient Satisfaction with Care

Patient satisfaction is linked to the amount of time spent with the physician. At the same time, long waiting times in hospitals are a major source of patient dissatisfaction. The aim of this study was to determine whether advance approval of outpatient chemotherapy (CT) via phone call can optimize healthcare delivery without compromising patient satisfaction with care. Between 2013 and 2016, 343 patients with breast/gynecological cancer scheduled to undergo CT on day 8 and/or day 15 of the CT cycle were enrolled in a before-after study conducted in a French comprehensive cancer center. In the control group, 168 patients received a face-to-face consultation with an oncologist on the day of CT for approval of the upcoming CT session. In the intervention group, 175 patients received a phone call from a healthcare provider the day before CT, where assessment of toxicity from the previous CT session was recorded and submitted to an oncologist for approval of the upcoming CT session. At the end of the 6th CT cycle, patient satisfaction was evaluated using EORTC IN-PATSAT32. A total of 233 questionnaires were analyzed (response rate: 77.7%). Satisfaction with care was similar between the two groups. No differences in perceived health status were observed, but self-reported time in hospital was lower in the intervention group than in the control group (p = 0.007). Advance approval of outpatient CT via phone call is feasible and particularly relevant in the current context of immunotherapy development.

Pembrolizumab versus investigator-choice chemotherapy for metastatic triple-negative breast cancer (KEYNOTE-119): a randomised, open-label, phase 3 trial

BACKGROUND

Pembrolizumab showed durable antitumour activity and manageable safety in metastatic triple-negative breast cancer in the single-arm KEYNOTE-012 and KEYNOTE-086 trials. In this study, we compared pembrolizumab with chemotherapy for second-line or third-line treatment of patients with metastatic triple-negative breast cancer.

METHODS

KEYNOTE-119 was a randomised, open-label, phase 3 trial done at 150 medical centres (academic medical centres, community cancer centres, and community hospitals) in 31 countries. Patients aged 18 years or older, with centrally confirmed metastatic triple-negative breast cancer, Eastern Cooperative Oncology Group performance status of 0 or 1, who had received one or two previous systemic treatments for metastatic disease, had progression on their most recent therapy, and had previous treatment with an anthracycline or taxane were eligible. Patients were randomly assigned (1:1) using a block method (block size of four) and an interactive voice-response system with integrated web-response to receive intravenous pembrolizumab 200 mg once every 3 weeks for 35 cycles (pembrolizumab group), or to single-drug chemotherapy per investigator's choice of capecitabine, eribulin, gemcitabine, or vinorelbine (60% enrolment cap for each; chemotherapy group). Randomisation was stratified by PD-L1 tumour status (positive [combined positive score (CPS) ≥1] vs negative [CPS <1]) and history of previous neoadjuvant or adjuvant treatment versus de-novo metastatic disease at initial diagnosis. Primary endpoints were overall survival in participants with a PD-L1 combined positive score (CPS) of 10 or more, those with a CPS of 1 or more, and all participants; superiority of pembrolizumab versus chemotherapy was tested in all participants only if shown in those with a CPS of one or more. The primary endpoint was analysed in the intention-to-treat population; safety was analysed in the all-subjects-as-treated population. This Article describes the final analysis of the trial, which is now completed. This trial is registered with ClinicalTrials.gov, number NCT02555657.

FINDINGS

From Nov 25, 2015, to April 11, 2017, 1098 participants were assessed for eligibility and 622 (57%) were randomly assigned to receive either pembrolizumab (312 [50%]) or chemotherapy (310 [50%]). Median study follow-up was 31·4 months (IQR 27·8-34·4) for the pembrolizumab group and 31·5 months (27·8-34·6) for the chemotherapy group. Median overall survival in patients with a PD-L1 CPS of 10 or more was 12·7 months (95% CI 9·9-16·3) for the pembrolizumab group and 11·6 months (8·3-13·7) for the chemotherapy group (hazard ratio [HR] 0·78 [95% CI 0·57-1·06]; log-rank p=0·057). In participants with a CPS of 1 or more, median overall survival was 10·7 months (9·3-12·5) for the pembrolizumab group and 10·2 months (7·9-12·6) for the chemotherapy group (HR 0·86 [95% CI 0·69-1·06]; log-rank p=0·073). In the overall population, median overall survival was 9·9 months (95% CI 8·3-11·4) for the pembrolizumab group and 10·8 months (9·1-12·6) for the chemotherapy group (HR 0·97 [95% CI 0·82-1·15]). The most common grade 3-4 treatment-related adverse events were anaemia (three [1%] patients in the pembrolizumab group vs ten [3%] in the chemotherapy group), decreased white blood cells (one [<1%] vs 14 [5%]), decreased neutrophil count (one [<1%] vs 29 [10%]), and neutropenia (0 vs 39 [13%]). 61 (20%) patients in the pembrolizumab group and 58 (20%) patients in the chemotherapy group had serious adverse events. Three (<1%) of 601 participants had treatment-related adverse events that led to death (one [<1%] in the pembrolizumab group due to circulatory collapse; two [1%] in the chemotherapy group, one [<1%] due to pancytopenia and sepsis and one [<1%] haemothorax).

INTERPRETATION

Pembrolizumab did not significantly improve overall survival in patients with previously treated metastatic triple-negative breast cancer versus chemotherapy. These findings might inform future research of pembrolizumab monotherapy for selected subpopulations of patients, specifically those with PD-L1-enriched tumours, and inform a combinatorial approach for the treatment of patients with metastatic triple-negative breast cancer.

FUNDING

Merck Sharp & Dohme.

High resolution small-scale inorganic scintillator detector: HDR brachytherapy application

PURPOSE

Brachytherapy (BT) deals with high gradient internal dose irradiation made up of a complex system where the source is placed nearby the tumor to destroy cancerous cells. A primary concern of clinical safety in BT is quality assurance to ensure the best matches between the delivered and prescribed doses targeting small volume tumors and sparing surrounding healthy tissues. Hence, the purpose of this study is to evaluate the performance of a point size inorganic scintillator detector (ISD) in terms of high dose rate brachytherapy (HDR-BT) treatment.

METHODS

A prototype of the dose verification system has been developed based on scintillating dosimetry to measure a high dose rate while using an ¹⁹² Ir BT source. The associated dose rate is measured in photons/s employing a highly sensitive photon counter (design data: 20 photons/s). Dose measurement was performed as a function of source-to-detector distance according to TG43U1 recommendations. Overall measurements were carried out inside water phantoms keeping the ISD along the BT needle; a minimum of 0.1 cm distance was maintained between each measurement point. The planned dwell times were measured accurately from the difference of two adjacent times of transit. The ISD system performances were also evaluated in terms of dose linearity, energy dependency, scintillation stability, signal-to-noise ratio (SNR), and signal-to-background ratio (SBR). Finally, a comparison was presented between the ISD measurements and results obtained from TG43 reference dataset.

RESULTS

The detection efficiency of the ISD was verified by measuring the planned dwell times at different dwell positions. Measurements demonstrated that the ISD has a perfectly linear behavior with dose rate (R²  = 1) and shows high SNR (>35) and SBR (>36) values even at the lowest dose rate investigated at around 10 cm from the source. Standard deviation (1σ) remains within 0.03% of signal magnitude, and less than 0.01% STEM signal was monitored at 0.1 cm source-to-detector distance. Stability of 0.54% is achieved, and afterglow stays less than 1% of the total signal in all the irradiations. Excellent symmetrical behavior of the dose rate regarding source position was observed at different radiation planes. Finally, a comparison with TG-43 reference dataset shows that corrected measurements agreed with simulation data within 1.2% and 1.3%, and valid for the source-to-detector distance greater than 0.25 cm.

CONCLUSION

The proposed ISD in this study anticipated that the system could be promoted to validate with further clinical investigations. It allows an appropriate dose verification with dwell time estimation during source tracking and suitable dose measurement with a high spatial resolution both nearby (high dose gradient) and far (low dose gradient) from the source position.

Abstract PD14-04: Contribution of tumor and immune cells to PD-L1 as a predictive biomarker in triple-negative breast cancer (TNBC): Analysis from KEYNOTE-119

Background: Pembrolizumab monotherapy did not significantly improve overall survival (OS) as second- or third-line treatment for metastatic TNBC vs chemotherapy in the randomized, open-label, phase 3 KEYNOTE-119 study (NCT02555657; N = 622). However, the benefit of pembrolizumab compared with chemotherapy appeared to be greater with increasing PD-L1 expression as quantified by combined positive score (CPS; defined as the number of PD-L1–staining cells [tumor cells, lymphocytes, macrophages] divided by the total number of viable tumor cells, multiplied by 100). In the current exploratory analysis, we aimed to determine whether expression of PD-L1 on tumor cells contributes to the value of PD-L1 as a predictive biomarker in metastatic TNBC.Methods: Patients with centrally confirmed TNBC and 1 or 2 prior systemic treatments for metastatic disease were enrolled in KEYNOTE-119. Patients were randomly assigned 1:1 to pembrolizumab 200 mg Q3W or investigator’s choice of single-agent chemotherapy (capecitabine, eribulin, gemcitabine, or vinorelbine). PD-L1 expression in tumor samples was assessed using PD-L1 IHC 22C3 pharmDx and quantified per tumor proportion score (TPS; defined as the percentage of PD-L1–expressing tumor cells [partial or complete membrane staining] relative to total number of tumor cells) and CPS. Quantitative immune cell density (QID) was defined as CPS minus TPS. QID isolates immune cells but may be truncated when TPS is high. The ability of each scoring method (TPS, CPS, and QID) to predict objective response rate (ORR) with pembrolizumab, including receiver operating characteristics (ROC) analysis, and OS hazard ratios (HRs; pembrolizumab vs chemotherapy) was evaluated.Results: Tumor samples were available for 601 patients (pembrolizumab, 309; chemotherapy, 292) in KEYNOTE-119. ORR was 9.7% (30/309) with pembrolizumab and 11.3% (33/292) with chemotherapy when PD-L1 expression status was not considered. In the pembrolizumab arm, the area under the ROC curve (AUROC; 95% CI) was 0.69 (0.58-0.80) for tumor samples scored for CPS, 0.66 (0.55-0.77) for QID, and 0.55 (0.46-0.64) for TPS. ROC analysis is shown in the Table. At each cutoff, QID had lower estimated sensitivity (ie, missed responders) and a lower Youden Index compared with CPS. The number of missed responders (of 30 total in the pembrolizumab arm) for QID relative to CPS were 2, 5, 5, 6, 2, and 2 at cutoffs of 1, 10, 20, 30, 40, and 50, respectively. Across all practical cutoffs, the OS HR tended to be slightly smaller for CPS than QID. At cutoffs corresponding to the upper percentiles of 10, 20, 40, and 60, OS HRs were 0.497, 0.658, 0.758, and 0.850, respectively, for CPS vs 0.572, 0.712, 0.814, and 0.863, respectively, for QID. QID appeared to be orthogonal to TPS (r = -0.03 for all 601 observations; r = -0.04 after eliminating 7 potentially truncated values).Conclusions: Trends estimated using KN119 suggest that tumor cell expression is an important component of PD-L1 as a predictive biomarker of pembrolizumab efficacy in metastatic TNBC. In this exploratory analysis, when immune cells alone were used to measure PD-L1 expression, a meaningful number of responders was missed and OS benefit trended toward higher HR estimates. Tumor and immune cell PD-L1 expression may represent distinct (presumably negative modulatory) mechanisms.

Table. ROC AnalysisCutoffCPS SensCPS SpecCPS YICPS PrevQID SensQID SpecQID YIQID PrevTPS SensTPS SpecTPS YITPS Prev010011001100110.8330.3660.1990.6540.7670.4160.1820.6020.3000.7890.0890.220100.5670.7170.2840.3110.4000.8140.2140.2070.2000.8920.0920.117200.5000.8490.3490.1840.3330.9250.2580.1000.1670.9320.0990.078300.3670.8920.2590.1330.1670.9570.1240.0550.1000.9430.0430.061400.2000.9350.1350.0780.1330.9860.1190.0260.0670.9530.0200.049500.2000.9570.1570.0580.1330.9930.1260.0190.0670.9680.0340.036

Citation Format: Eric P. Winer, Oleg Lipatov, Seock-Ah Im, Anthony Goncalves, Eva Muñoz-Couselo, Keun Seok Lee, Zbigniew Nowecki, Peter Schmid, Kenji Tamura, Laura Testa, Isabell Witzel, Shoichiro Ohtani, Stephanie Hund, Karina Kulangara, Vassiliki Karantza, Jaime A. Mejia, Junshui Ma, Petar Jelinic, Lingkang Huang, Kenneth Emancipator, Javier Cortes. Contribution of tumor and immune cells to PD-L1 as a predictive biomarker in triple-negative breast cancer (TNBC): Analysis from KEYNOTE-119 [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PD14-04.

Abstract PS12-01: Pembrolizumab versus chemotherapy for previously treated metastatic triple-negative breast cancer (KEYNOTE-119): Efficacy in patients with lung or liver metastases

Background: KEYNOTE-119 (NCT02555657) is a randomized, open-label phase 3 study of pembrolizumab (pembro) monotherapy vs single-agent chemotherapy (chemo) in patients with previously treated metastatic triple-negative breast cancer (mTNBC). The results showed directionally favorable improvement in overall survival (OS) with pembro compared to chemo in patients with PD-L1−positive tumors, although statistical superiority was not demonstrated. The pembro treatment effect increased with PD-L1 enrichment, as measured by the combined positive score (CPS). Since treatment outcomes may vary by location of metastasis, we performed a retrospective, exploratory analysis to evaluate the efficacy of pembro vs chemo among patients with lung or liver metastasis at baseline enrolled in KEYNOTE-119.

Methods: Patients with centrally confirmed TNBC, 1-2 prior systemic treatments for metastatic disease, documented progression on most recent therapy and prior treatment with an anthracycline and/or taxane were randomized 1:1 to pembro 200 mg Q3W or single-agent chemo per investigator’s choice of capecitabine, eribulin, gemcitabine, or vinorelbine (60% enrollment cap for each). Patients were stratified by PD-L1 status (CPS &lt;1 vs ≥1) and history of prior neoadjuvant/adjuvant treatment vs de novo metastatic disease at initial diagnosis. Primary study end points were OS in patients with PD-L1 CPS ≥10, patients with CPS ≥1, and all patients.

Results: Overall, 622 patients were randomized in KEYNOTE-119 (pembro, n=312; chemo, n=310); median follow-up was 31 months at the April 11, 2019 data cutoff date. At baseline, 403 (65%) patients had lung metastasis and 173 (28%) had liver metastasis. Pembro did not improve OS vs chemo in patients with lung or liver metastases in the ITT population, although the HRs decreased as tumor PD-L1 expression increased, with the greatest benefit observed in patients with PD-L1 CPS ≥20 tumors (Table). Similar trends were observed for progression-free survival, objective response rate, and duration of response. In both treatment groups, presence of liver metastases at baseline was associated with shorter OS as compared to absence of liver metastases at baseline; this trend was not observed for lung metastases. Results should be interpreted with caution due to modest patient sample size in some subgroups.

Conclusion: Among patients with previously treated mTNBC who had lung or liver metastases for whom prognosis is typically poor, pembro monotherapy showed a benefit vs single-agent chemo in patients with increasing PD-L1 tumor enrichment. These findings are consistent with the results from the global study population.

Table. Analysis of Overall SurvivalITTCPS ≥1CPS ≥10CPS ≥20NMedian, mo (95% CI)HR (95% CI)NMedian, mo (95% CI)HR (95% CI)NMedian, mo (95% CI)HR (95% CI)NMedian, mo (95% CI)HR (95% CI)Patients With Lung MetastasesPembro2009.8 (7.4-11.7)0.99 (0.80-1.23)12710.6 (8.1-12.5)0.85 (0.65-1.10)5612.8 (9.3-17.2)0.80 (0.53-1.18)3117.0 (11.7-27.1)0.55 (0.32-0.95)Chemo20311.4 (8.7-13.1)13110.4 (7.2-12.7)6311.9 (7.3-14.9)3413.0 (7.2-15.8)Patients Without Lung MetastasesPembro11210.3 (8.3-13.6)0.92 (0.69-1.23)7610.8 (8.9-15.7)0.89 (0.63-1.26)4012.1 (8.6-16.4)0.79 (0.47-1.31)2612.8 (7.8-23.0)0.63 (0.32-1.24)Chemo10710.2 (7.2-12.7)719.9 (7.0-13.5)3511.3 (7.0-15.7)1810.5 (5.2-15.7)Patients With Liver MetastasesPembro876.5 (4.7-9.3)1.04 (0.76-1.43)577.7 (4.2-9.9)1.02 (0.69-1.51)2410.3 (6.2-16.4)0.78 (0.44-1.39)1310.7 (6.2-19.0)0.69 (0.31-1.53)Chemo866.5 (5.4-8.4)546.5 (5.4-7.8)317.2 (5.2-11.6)207.5 (2.9-14.7)Patients Without Liver MetastasesPembro22510.9 (9.2-12.6)0.95 (0.78-1.17)14612.4 (10.5-14.2)0.82 (0.64-1.05)7213.0 (10.1-17.2)0.80 (0.55-1.16)4416.0 (11.4-27.1)0.57 (0.33-0.95)Chemo22412.6 (10.6-13.9)14812.6 (9.8-13.6)6712.7 (9.8-15.8)3214.3 (8.3-16.8)

Citation Format: Eric Winer, Oleg Lipatov, Seock-Ah Im, Anthony Goncalves, Keun Seok Lee, Peter Schmid, Laura Testa, Isabell Witzel, Shoichiro Ohtani, NIcholas Turner, Stefania Zambelli, Nadia Harbeck, Fabrice Andre, Rebecca Dent, Jianxin Lin, Vassiliki Karantza, Jaime Mejia, Javier Cortes. Pembrolizumab versus chemotherapy for previously treated metastatic triple-negative breast cancer (KEYNOTE-119): Efficacy in patients with lung or liver metastases [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PS12-01.

Abstract PS12-05: First efficacy results of a 2-stage Simon’s design randomised phase 2 of darolutamide or capecitabine in patients with triple-negative, androgen receptor positive advanced breast cancer (UCBG06-3)

Background: Triple negative breast cancer (TNBC) is an heterogeneous disease and encompasses at least 4 subtypes. One of these expresses the androgen receptor (AR). Several prospective trials demonstrated antitumour efficacy with anti-androgen treatment in patients with advanced breast cancer. Darolutamide is an androgen-receptor antagonist with a potent anti-tumour efficacy in metastatic prostate cancer with a favorable safety profile. We conducted a randomized non-comparative phase II trial to study the efficacy and tolerability of darolutamide and capecitabine in AR-positive TNBC (NCT03383679).

Material and methods: Patients (Pts) with a metastatic, centrally reviewed, AR-positive (≥ 10% by immunohistochemistry) and TNBC who have received a maximum of one line of chemotherapy for advanced disease were eligible. They were randomised in a 2:1 ratio to receive darolutamide (D arm) 600 mg twice daily or capecitabine (C arm) at 1000 mg/m² twice daily 2 weeks on and 1-week off, until progression or unacceptable toxicity. The primary endpoint was clinical benefit rate (CBR) defined as the proportion of pts presenting a complete response (CR), partial response (PR), or stable disease (SD) at 16 weeks. Main secondary endpoints included objective response rate, overall survival, progression-free survival and safety. An interim statistical analysis was planned when 19 assessable pts will be available in the D arm. According to an optimal 2-stage Simon’s design,if &lt;5 patients experienced a CBR the trial should be stopped for futility; if 5 or more experienced a CBR the trial should continue up to a total of 54 patients in the D arm.

Results: Out of 133 pts screened and centrally analyzed, from 37 centres, 54% (72/133) were AR-positive. 45 pts were randomized (29 in D arm and 16 in C arm) from April 2018 to December 2019. In arm D, median age was 60 years (range 47-88). and 13.8 % received a first line of chemotherapy for metastatic disease. A total of 19 pts were eligible and assessable for the primary endpoint in D arm. 5 CBR were confirmed at 16 weeks (26.3%; 95% CI: 9.2%-51.2 %) including 1 confirmed PR and 4 SD. In arm D, fatigue (23.8%), ASAT increased (23.8%), and blood alkaline phosphatase increased (23.8%) were the most common drug-related adverse events; the majority of them being grade 1 or 2. 6 pts presented with drug-related serious adverse events: one in D arm and 5 in C arm.

Conclusions: According to the planned interim analysis, the efficacy objective is met (5 CBR) in D arm. Moreover, darolutamide is well tolerated. Thus, patients are now recruited in the second stage.

Keywords: Androgen receptor,triple-negative breast cancer, darolutamide, advanced breast cancer

Citation Format: Hervé Bonnefoi, Florence Lerebours, Olivier Tredan, Florence Dalenc, Christelle Levy, Mahasti Saghatchian, Marie Ange Mouret Reynier, Delphine Mollon, Severine Guiu, Laurence Venat Bouvet, Elisabeth Carola, Geraldine Martineau, Marina Pulido, Gaetan MacGrogan, Anthony Goncalves. First efficacy results of a 2-stage Simon’s design randomised phase 2 of darolutamide or capecitabine in patients with triple-negative, androgen receptor positive advanced breast cancer (UCBG06-3) [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PS12-05.

Abstract PD3-08: Tucatinib vs placebo in combination with trastuzumab and capecitabine for patients with locally advanced unresectable or HER2-positive metastatic breast cancer (HER2CLIMB): Outcomes by hormone receptor status

Background Tucatinib (TUC) is a highly selective oral tyrosine kinase inhibitor of HER2 with minimal inhibition of EGFR. It was recently approved by the FDA for patients (pts) with HER2+ metastatic breast cancer (MBC), including pts with brain metastases (BM) whose cancers have progressed on at least 1 prior anti-HER2 regimen in the metastatic setting. In the HER2CLIMB (NCT02614794) pivotal trial, pts with HER2+ MBC previously treated with trastuzumab (T), pertuzumab, and trastuzumab emtansine (T-DM1) were randomized to receive TUC or placebo in combination with T and capecitabine (C). The addition of TUC resulted in clinically meaningful and statistically significant improvements in overall survival (OS), progression-free survival (PFS), and objective response rate (ORR) in HER2+ MBC pts. Primary methods and outcomes have been reported previously (Murthy, NEJM 2019). Here we present an exploratory analysis describing the outcomes in the HER2CLIMB trial based on hormone receptor (HR) status.

Methods Pts were randomized 2:1 to receive TUC or placebo in combination with T and C. All pts had a baseline brain MRI and randomization was stratified by presence of BM, ECOG status, and geographic region. All pts with HER2+ MBC who were positive for either or both estrogen receptor and progesterone receptor (&gt; 1%) were assigned to the HR “positive” subgroup. Pts not meeting the above criteria were assigned to the HR “negative” subgroup. For the exploratory HR+/HR- efficacy analysis presented here, PFS per RECIST 1.1 by blinded independent central review was evaluated in the first 480 pts enrolled. OS, PFS in pts with baseline BM, and confirmed ORR in pts with measurable disease were evaluated in the total study population. P values presented for PFS are nominal.

Results Overall, 612 pts were enrolled to HER2CLIMB; 370 pts (60%) had HR+ and 242 (40%) had HR- tumors. Baseline demographics and disease characteristics in HR+/HR- subgroups were generally balanced between treatment arms. In the HR+ group, there was a 42% reduction in the risk of progression or death in the TUC arm (hazard ratio: 0.58; 95% CI: 0.42, 0.80; P=0.0008); median (95% CI) PFS was 7.6 mo (7.4, 9.5) in the TUC arm vs 5.6 mo (4.3, 7.4) in the control arm. In the HR- group, there was a 46% reduction in the risk of progression or death in the TUC arm (hazard ratio: 0.54; 95% CI: 0.34, 0.86; P=0.008); median (95% CI) PFS was 8.1 mo (7.0, 11.6) in the TUC arm vs 4.2 mo (3.1, 8.6) in the control arm. In the total population, median OS was 21.7 mo vs 18.2 mo in HR+ in the TUC arm vs control arm, respectively; median OS in HR- was 31.1 mo in the TUC arm vs 14.1 mo in the control arm. In pts with BM in the HR+ group (n=166 [45%]), there was a 52% reduction in the risk of progression or death (hazard ratio: 0.48; 95% CI: 0.31, 0.75; P=0.0008); median (95% CI) PFS was 7.5 mo (5.6, 9.5) in the TUC arm vs 5.1 mo (4.1, 5.7) in the control arm, and median OS was 18.1 mo vs 12.8 mo, respectively. In pts with BM in the HR- group (n=125 [52%]), there was a 50% reduction in the risk of progression or death (hazard ratio: 0.50; 95% CI: 0.27, 0.95; P=0.03); median (95% CI) PFS was 7.8 mo (6.1, 11.6) in the TUC arm vs 5.4 mo (2.9, 8.6) in the control arm, and median OS was 18.5 mo vs 11.5 mo, respectively. In the total population, ORR was numerically higher in the TUC arm vs the control arm regardless of HR status (HR+: 37.4% [95% CI: 30.8, 44.5] vs 27.1% [95% CI: 19.0, 36.6], respectively and HR-: 45.3% [95% CI: 36.7, 54.0] vs 15.6% [95% CI: 7.8, 26.9], respectively).

Conclusions Among pts with HER2+ MBC previously treated with T, pertuzumab, and T-DM1, the addition of TUC to T and C showed clinically meaningful improvements of PFS, OS, and ORR independent of HR status. Furthermore, pts with HR+ and HR- MBC with BM derived similar benefit from the addition of TUC to T and C.

Citation Format: Erika Hamilton, Mattea Reinisch, Sherene Loi, Alicia Okines, Paula R. Pohlmann, Eva Harder Brix, Hugues Bourgeois, Belinda Yeo, Cheryl Aylesworth, Melody Cobleigh, Anthony Goncalves, Rebecca Moroose, Katherine H.R. Tkaczuk, Michaela Tsai, Christine Simmons, Michael Andersson, Hatem Soliman, Michelina Cairo, Lisa A. Carey, David Cameron, Jorge Ramos, Wentao Feng, Mafalda Oliveira. Tucatinib vs placebo in combination with trastuzumab and capecitabine for patients with locally advanced unresectable or HER2-positive metastatic breast cancer (HER2CLIMB): Outcomes by hormone receptor status [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PD3-08.

Abstract OT-13-05: Dolaf- an international multicenter phase 2 trial of durvalumab (medi4736) plus olaparib plus fulvestrant in metastatic or locally advanced er-positive, her2-negative breast cancer patients selected using criteria that predict sensitivity to olaparib (UCBG308)

Background: Olaparib is a PARP inhibitor that has shown high response rates and clinical activity in patients with advanced HER2-negative breast cancer (BC) and a germline BRCA1 and BRCA2 mutation. There is also evidence of cellular sensitivity to PARP inhibitors associated to defects in other genes involved in homologous recombination DNA repair (HRR) or mismatch repair pathway (microsatellite instability MSI). Moreover, about 15% of patients with ER+/HER2- metastatic BC have at least 100 mutations in their tumor, leading to genomic instability and potential sensitivity to PARP inhibitors. Several preclinical and clinical studies have suggested the benefit of an association of immune checkpoint blockade, like durvalumab, with PARP inhibitor. Indeed, tumors with BRCA1/2 mutations or other deficiency in HRR have high mutagenic burden and produce a larger number of neoantigens. Most BRCA-associated BC are ER+/HER2-. Although loss of the BRCA gene function is a key driver of oncogenesis in these patients, ER-pathway appears to remain a key target for their therapy. Preclinical data indicate that olaparib may enhance endocrine therapy efficacy and circumvent resistance. Therefore, the combination of durvalumab, olaparib and endocrine therapy could be a therapeutic option for patients with BRCA1/2 mutation or for patients with selected ER+/HER2- advanced BC.

Trial design: DOLAF is an open-label, international, multicentric, phase II trial assessing the combination of olaparib, fulvestrant, and durvalumab. Olaparib will be administered orally twice daily at 300 mg. Fulvestrant will be administered as two intramuscular injections of 250 mg (Cycle 1 Days 1 and 15, and Day 1 of each subsequent 28-day cycle). Durvalumab will be started 4 weeks after the first dose of olaparib at 1500 mg intravenous every 4 weeks.

Eligibility criteria include: ER+/HER2- metastatic or locally advanced BC with documented germline alteration in BRCA1 or BRCA2 or deleterious germline or somatic alterations implicated in the HRR pathway (ATM, BARD1, BRCA1, BRCA2, BRIP1, CDK12, CHEK1, CHEK2, FANCA, FAND2, FANCL, MRE11A, NBN, PALB2, PPP2R2A, RAD51B, RAD51C, RAD51D and RAD54L) or in MSI status or other actionable genes (AKT1, ESR1, FGFR1, FGFR2, FGFR3, and PIK3CA) all based on central tumor next generation DNA sequencing. Patients could have received 1 line of endocrine therapy and/or 1 line of chemotherapy in the metastatic setting.Specific aims: To evaluate the efficacy of the combination in terms of progression-free survival rate at 24 weeks using RECIST v1.1. Secondary endpoints include: safety (according to the NCI-CTCAE v5.0), overall survival, progression-free survival, objective response rate, duration of response in the overall study population and in the germline BRCA mutated population.

Statistical methods: Given the lack of safety data from this association, a safety run-in of 6 patients was planned. With an optimum two-stage Simon design,α = 2.5%, β = 5%, p0 (the probability of inefficiency maximum) = 50%, p1 (the probability of minimum efficiency) = 65%, it would be necessary to include 149 evaluable patients. The strategy could be considered sufficiently effective if there are at least 87 successes. According to the established design (including a rate of 5% of patients lost to follow-up or non-evaluable), it will be necessary to include 158 patients. We hypothesized that about 20% of screened patients will have a molecular alteration to allow enrollment. Thus, we need to screen 790 patients.

The study is recruiting. The safety run-in is over. By July 1, 2020, 62 patients have been screened and 8 have been treated (NCT04053322). Contact information: DOLAF@unicancer.fr

Citation Format: Severine Guiu, Judith Balmana, Lise Roca, Anthony Goncalves, Audrey Mailliez, Frederic Bigot, Thomas Bachelot, Florence Dalenc, Nadine Dohollou, Dominique Genet, Isabelle Desmoulins, Camille Chakiba, Suzette Delaloge, Geraldine Martineau, Veronique Haddad, Philippe Follana. Dolaf- an international multicenter phase 2 trial of durvalumab (medi4736) plus olaparib plus fulvestrant in metastatic or locally advanced er-positive, her2-negative breast cancer patients selected using criteria that predict sensitivity to olaparib (UCBG308) [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr OT-13-05.

Management and outcome of male metastatic breast cancer in the national multicenter observational research program Epidemiological Strategy and Medical Economics (ESME)

Background and Aims:

Because of its low prevalence, metastatic breast cancer (MBC) in males is managed based on clinical experience with women. Using a real-life database, we aim to provide a comprehensive analysis of male MBC characteristics, management and outcome.

Methods:

The Epidemiological Strategy and Medical Economics Data Platform collected data for all men and women ⩾18 years with MBC in 18 participating French Comprehensive Cancer Centers from January 2008 to November 2016. Demographic, clinical, and pathological characteristics were retrieved, as was treatment modality. Men were matched 1:1 to women with similar characteristics.

Results:

Of 16,701 evaluable patients, 149 (0.89%) men were identified. These men were older (median age 69 years) and predominantly had hormone receptor HR+/HER2– disease (78.3%). Median overall survival (OS) was 41.8 months [95% confidence interval (CI: 26.9–49.7)] and similar to women. Median progression-free survival (PFS) with first-line therapy was 9.3 months [95% CI (7.4–11.5)]. In the HR+/HER2– subpopulation, endocrine therapy (ET) alone was the frontline treatment for 43% of patients, including antiestrogens (n = 19), aromatase inhibitors (n = 15) with luteinizing hormone-releasing hormone (LHRH) analogs (n = 3), and various sequential treatments. Median PFS achieved by frontline ET alone was similar in men [9.8 months, 95% CI (6.9–17.4)] and in women [13 months, 95% CI (8.4–30.9)] (p = 0.80). PFS was similar for HR+/HER2– men receiving upfront ET or chemotherapy: 9.8 months [95% CI (6.9–17.4)] versus 9.5 months [95% CI (7.4–11.7)] (p = 0.22), respectively.

Conclusion:

MBC management in men and women leads to similar outcomes, especially in HR+/HER2– patients for whom ET should also be a cornerstone. Unsolved questions remain and successfully recruiting trials for men are still lacking.

Quantification of Immune Variables from Liquid Biopsy in Breast Cancer Patients Links Vδ2+ γδ T Cell Alterations with Lymph Node Invasion

The rationale for therapeutic targeting of Vδ2+ γδ T cells in breast cancer is strongly supported by in vitro and murine preclinical investigations, characterizing them as potent breast tumor cell killers and source of Th1-related cytokines, backing cytotoxic αβ T cells. Nonetheless, insights regarding Vδ2+ γδ T cell phenotypic alterations in human breast cancers are still lacking. This paucity of information is partly due to the challenging scarcity of these cells in surgical specimens. αβ T cell phenotypic alterations occurring in the tumor bed are detectable in the periphery and correlate with adverse clinical outcomes. Thus, we sought to determine through an exploratory study whether Vδ2+ γδ T cells phenotypic changes can be detected within breast cancer patients' peripheral blood, along with association with tumor progression. By using mass cytometry, we quantified 130 immune variables from untreated breast cancer patients' peripheral blood. Supervised analyses and dimensionality reduction algorithms evidenced circulating Vδ2+ γδ T cell phenotypic alterations already established at diagnosis. Foremost, terminally differentiated Vδ2+ γδ T cells displaying phenotypes of exhausted senescent T cells associated with lymph node involvement. Thereby, our results support Vδ2+ γδ T cells implication in breast cancer pathogenesis and progression, besides shedding light on liquid biopsies to monitor surrogate markers of tumor-infiltrating Vδ2+ γδ T cell antitumor activity.

Real-life prognosis of 5041 bone-only metastatic breast cancer patients in the multicenter national observational ESME program

BACKGROUND

Bone-only (BO) metastatic breast cancer (MBC) is considered a more favorable entity than other MBC presentations. However, only few retrospective series and data from selected randomized controlled trials have been reported so far.

METHODS

Using the French national multicenter ESME (Epidemiological Strategy and Medico Economics) Data Platform, the primary objective of our study was to compare the overall survival (OS) of patients with BO versus non-BO MBC at diagnosis, with adjustment on main prognostic factors using a propensity score. Secondary objectives were to compare first-line progression-free survival (PFS1), describe treatment patterns, and estimate factors associated with OS.

RESULTS

Out of 20,095 eligible women, 5041 (22.4%) patients had BO disease [hormone-receptor positive (HR+)/human epidermal growth-factor-receptor-2 negative (HER2-), n = 4 102/13,229 (31%); HER2+, n = 644/3909 (16.5%); HR-/HER2-, n = 295/2 957 (10%)]. BO MBC patients had a better adjusted OS compared with non-BO MBC [52.1 months (95% confidence interval (CI) 50.3-54.1) versus 34.7 months (95% CI 34.0-35.6) respectively]. The 5-year OS rate of BO MBC patients was 43.4% (95% CI 41.7-45.2). They also had a better PFS1 [13.1 months (95% CI 12.6-13.8) versus 8.5 months (95% CI 8.3-8.7), respectively]. This observation could be repeated in all subtypes. BO disease was an independent prognostic factor of OS [hazard ratio 0.68 (95% CI 0.65-0.72), p < 0.0001]. Results were concordant in all analyses.

CONCLUSION

BO MBC patients have better outcomes compared with non-BO MBC, consistently, through all MBC subtypes.

Impact of body mass index on overall survival in patients with metastatic breast cancer

BACKGROUND

High Body mass index (BMI) is a risk factor for breast cancer among postmenopausal women and an adverse prognostic factor in early-stage. Little is known about its impact on clinical outcomes in patients with metastatic breast cancer (MBC).

METHODS

The National ESME-MBC observational cohort includes all consecutive patients newly diagnosed with MBC between Jan 2008 and Dec 2016 in the 18 French comprehensive cancer centers.

RESULTS

Of 22 463 patients in ESME-MBC, 12 999 women had BMI data available at MBC diagnosis. Median BMI was 24.9 kg/m² (range 12.1-66.5); 20% of women were obese and 5% underweight. Obesity was associated with more de novo MBC, while underweight patients had more aggressive cancer features. Median overall survival (OS) of the BMI cohort was 47.4 months (95% CI [46.2-48.5]) (median follow-up: 48.6 months). Underweight was independently associated with a worse OS (median OS 33 months; HR 1.14, 95%CI, 1.02-1.27) and first line progression-free survival (HR, 1.11; 95%CI, 1.01; 1.22), while overweight or obesity had no effect.

CONCLUSION

Overweight and obesity are not associated with poorer outcomes in women with metastatic disease, while underweight appears as an independent adverse prognostic factor.

Predictors of atrial fibrillation occurrence in patients with hypertrophic cardiomyopathy

Introduction

Patients with hypertrophic cardiomyopathy (HCM) are at increased risk of dysrhythmias, especially atrial fibrillation (AF).

Purpose

The aim of this study was to evaluate the incidence of AF in HCM patients (P) and to determine predictors of AF.

Methods

Retrospective analysis of HCM P at a single tertiary center. Baseline clinical, echocardiographic and cardiovascular magnetic resonance (CMR) characteristics were collected. On follow up AF was identified by electrocardiogram and/or 24 hours Holter monitoring.

Results

61P (59% male) were included, with a mean age of 58±2 years. 27.9% had angina (all of them CCS 2), 34.4% were in NYHA II and 14.8% in NYHA III, 8.2% had syncope and 39.3% had palpitations. A family history of sudden cardiac death (SCD) or cardiomyopathy was present in 40.4% of the cases. The mean HCM risk SCD score was 3.35±0.28%. On echocardiography left atrium (LA) diameter was 44.86±0.87mm, LA volume (LAvol) was 89.97±5.39mL (indexed LAvol 46.05±2.55mL/m2), interventricular septum (IVS) was 16.83±0.663mm, left ventricle (LV) mass was 290.94±13.897g and maximum wall thickness (MWT) was 20.59±0.596mm. 77% P had LA enlargement. 88.5%P had late gadolinium enhancement (LGE) in CMR with a median number of 5±7 segments involved. AF developed in 23P (37.7%), with a mean age of 58±3 years. Predictors of AF development were NYHA III (p=0.007), risk score (p=0.007), LA diameter (p=0.007), LAvol (p=0.005) and indexed LAvol (p=0.002), MWT (p=0.0015), LGE in more than 5 segments (p=0.029) and LGE in the inferior basal and inferior median IVS (p=0.033 and p=0.042). The only independent predictor was LAvol (p=0.0012), with an area under the curve of 0.755 and a cut off of 85.9mL being the best predictor (p=0.004). Combining LAvol &gt;85.9mL with LGE involving &gt;5 segments and LAvol &gt;85.9mL with LGE in inferior basal IVS (IBIVS) a statistically significant difference between groups was achieved (p=0.009 in the combined predictor LAvol + LGE &gt;5 segments and p=0.002 in the combined predictor LAvol + LGE in IBIVS) (figure 1 and figure 2). In a multivariable analysis including these 2 combined predictors and LAvol alone the only independent predictor was the combination of LAvol + IBIVS involvement.

Conclusion

AF is frequent in patients with HCM and develops in younger ages than in general population. NYHA III, risk score, LA diameter, LAvol, MWT, LGE &gt;5 segments and LGE in IBIVS and in IMIVS were predictors of AF, with LAvol being the independent predictor. The combination of LAvol with LGE &gt;5 segments and LAvol with LGE in IBIVS presented stronger predictor value comparing with these characteristics alone.

Funding Acknowledgement

Type of funding source: None

VEGF-Related Germinal Polymorphisms May Identify a Subgroup of Breast Cancer Patients with Favorable Outcome under Bevacizumab-Based Therapy-A Message from COMET, a French Unicancer Multicentric Study

The prospective multicenter COMET trial followed a cohort of 306 consecutive metastatic breast cancer patients receiving bevacizumab and paclitaxel as first-line chemotherapy. This study was intended to identify and validate reliable biomarkers to better predict bevacizumab treatment outcomes and allow for a more personalized use of this antiangiogenic agent. To that end, we aimed to establish risk scores for survival prognosis dichotomization based on classic clinico-pathological criteria combined or not with single nucleotide polymorphisms (SNPs). The genomic DNA of 306 patients was extracted and a panel of 13 SNPs, covering seven genes previously documented to be potentially involved in drug response, were analyzed by means of high-throughput genotyping. In receiver operating characteristic (ROC) analyses, the hazard model based on a triple-negative cancer phenotype variable, combined with specific SNPs in VEGFA (rs833061), VEGFR1 (rs9582036) and VEGFR2 (rs1870377), had the highest predictive value. The overall survival hazard ratio of patients assigned to the poor prognosis group based on this model was 3.21 (95% CI (2.33-4.42); p < 0.001). We propose that combining this pharmacogenetic approach with classical clinico-pathological characteristics could markedly improve clinical decision-making for breast cancer patients receiving bevacizumab-based therapy.

Insights from microRNAs into the pathophysiology of coronary and multiterritorial atherosclerosis

Introduction

The mechanisms underlying the different phenotypic presentations of atherosclerosis are still poorly understood. MicroRNAs regulate genetic expression at the post-transcriptional level and each has specific biological functions. MicroRNAs could therefore be useful for understanding the epigenetic drivers for development of isolated coronary atherosclerosis and more extensive disease (coronary and extra-coronary). We evaluated if the expression profile of circulating microRNAs was associated with coronary and multiterritorial atherosclerosis.

Methods

We prospectively recruited three groups of age- and sex-matched participants, with: 1) no coronary atherosclerosis (calcium score=0, no soft plaques in coronary angioCT scan), neither carotid or inferior limbs atherosclerosis (controls); 2) isolated obstructive coronary artery disease (CAD) (≥50% for the left main, ≥70% for other epicardial vessels) (isolated CAD group); 3) obstructive disease of the coronary, inferior limbs and carotid arterial beds (multi-territorial disease group). Obstructive atherosclerosis of carotid and inferior limbs arteries (≥50% stenosis by Doppler or angioCT imaging) was assessed in all participants. Acute atherosclerotic events or coronary revascularization within 12 months, heart failure, infections, malignancy and severe renal dysfunction were exclusion criteria. Six microRNAs with diverse mechanisms of action were selected (mir-21, miR-27b, miR-29a, miR-126, miR-146, miR-218) and measurements of their circulating levels were performed in a blinded fashion, using RT-PCR SYBR Green.

Results

Twenty four patients were included, including 8 patients in each group. Mean age was 61±9 years, and 83% were male. In patients with atherosclerosis, classical cardiovascular risk factors were globally more prevalent. The expression of miR-146 and miR-218, both of which regulate endothelial function, was significantly decreased in the isolated CAD group compared to controls (Figure; data are expressed as median [IQR]). There was a further decrease in the expression of both microRNAs in patients with multiterritorial atherosclerosis compared to patients with isolated CAD. The expression of other microRNAs did not differ. Smoking was associated with the presence of isolated CAD and multiterritorial atherosclerosis (14% vs 30% vs 56% of smokers across groups, p=0.002), and with a decreased expression of miR-218 (1.6 [0.02–83] fold vs 0.1 [0.001–0.7] fold, p=0.023).

Conclusions

The expression of the endothelial regulators miR-146 and miR-218 was decreased in patients with isolated CAD compared to controls, and even more hampered in patients with multiterritorial atherosclerosis. Higher degrees of endothelial dysfunction may therefore contribute to a more diffuse atherosclerotic presentation through miR-146 and miR-218. Atherogenesis related to smoking may be partially mediated by miR-218.

Funding Acknowledgement

Type of funding source: None

Innate immunity is linked to the severity of stable coronary artery disease through sCD40L pathway

Introduction

Soluble CD40 ligand (sCD40L) activates different cell types involved in innate immunity, including macrophages and platelets. The influence of innate immunity, particularly of sCD40L pathway, on stable coronary artery disease (SCAD) expression is not fully understood. We evaluated if sCD40L expression is related to the presence of SCAD and to its clinical and anatomical severity.

Methods

We prospectively recruited two groups of age- and sex-matched participants: 1) without coronary artery disease (CAD) (calcium score=0, no soft plaques on coronary angioCT scan) (controls); and 2) with stable obstructive CAD (≥50% for the left main, ≥70% for other epicardial vessels, on invasive coronary angiography). Acute atherosclerotic events or coronary artery bypass grafting (CABG) within 12 months, previous percutaneous coronary intervention, heart failure, infection, malignancy and severe renal dysfunction were exclusion criteria. Clinical, laboratorial and anatomical data were prospectively collected. Serum was stored at −80°C and measurements were performed in a blinded fashion, by ELISA (sCD40L Human Quantikine).

Results

Sixty-three participants were included: 14 controls and 49 patients with SCAD. In SCAD patients, classical cardiovascular risk factors were globally more prevalent and the serum levels of sCD40L (5553±3356 vs 3099±644 ng/mL, p&lt;0.001), leucocytes counts (7.6±1.8 vs 6.4±1.7x109/L, p=0.010), neutrophils counts (4.4±1.5 vs 3.5±1.5x109/L, p=0.010) and neutrophils/lymphocytes ratio (2.4±1.1 vs 1.9±0.7, p=0.019) were significantly higher, while c-reactive protein (CRP) levels did not differ, compared to controls. sCD40L levels were positively correlated with leucocytes (r=0.36) and neutrophils (r=0.28) counts (all p&lt;0.05), but not with CRP. Clinically, sCD40L levels were associated (ANOVA p&lt;0.001) and positively correlated (Pearson r=0.54, p&lt;0.001) with angina severity (Fig. 1A). Anatomically, patients with a higher number of significant coronary artery lesions presented higher sCD40L levels (Fig. 1B); sCD40L levels were positively correlated with the number of: diseased vessels (r=0.33), significant coronary artery lesions (r=0.31), and all coronary artery lesions (r=0.33) (all p&lt;0.05), without correlation with the Gensini score. Linear regression analysis considering clinical and laboratorial data revealed that sCD40L was an independent predictor of CAD severity, as assessed by the number of significant lesions (model: sCD40L β 0.28, 95% CI 0.03–0.34; hypertension β 1.1, 95% CI 0.97–3.64). Among SCAD patients, those with previous CABG (n=15) had lower sCD40L levels than patients waiting for revascularization (n=34) (3317±1680 vs 6793±3631 ng/mL, p&lt;0.001).

Conclusions

Increased expression of sCD40L was associated with the presence of SCAD, with angina severity and with CAD severity, while previous revascularization was associated with decreased sCD40L levels.

Funding Acknowledgement

Type of funding source: None

Prognostic value of the cardiorespiratory optimal point during submaximal exercise testing

Background

Peak oxygen consumption (pVO2) is a key parameter in assessing the prognosis of heart failure with reduced ejection fraction (HFrEF) patients (pts). However, it is a less reliable parameter when the cardiopulmonary exercise test (CPET) is not maximal. It is crucial to identify the submaximal exercise variables with the best prognostic power (PP), in order to improve the management of pts that cannot attain a maximal CPET.

Purpose

The aim of this study was to evaluate and compare the PP of several exercise parameters in submaximal CPET for risk stratification in pts with HFrEF.

Methods

Prospective evaluation of adult pts with HFrEF submitted to CPET in a tertiary center. A submaximal CPET was defined by a respiratory exchange ratio (RER) ≤1.10. Pts were followed up for at least 1 year for the primary endpoint of cardiac death and urgent heart transplantation/ ventricular assist device implantation. Several CPET parameters were analyzed as potential predictors of the combined endpoint and their PP (area under the curve - AUC) was compared to that of pVO2, using the Hanley and McNeil test.

Results

CPET was performed in 487 HF pts, of which 317 (66%) performed a submaximal CPET. Pts averaged 57±12 years of age, 77% were male, 45.7% had ischemic cardiomyopathy, with a mean LVEF of 30.4±7.6%, a mean heart failure survival score of 8.6±1.1. The mean pVO2 was 17.1±5.5 ml/kg/min and the mean RER 1.01±0.08. During a mean follow-up (FU) time of 11±1 months, 18 pts (6%) met the primary endpoint. Cardiorespiratory optimal point (OP - VE/VO2) had the highest AUC value (0.915, p=0.001), followed by the partial pressure of end-tidal CO2 at the anaerobic threshold - PETCO2L (0.814, p&lt;0.001). pVO2 presented an AUC of 0.730 (p=0.001). OP≥31 and PETCO2L ≤37mmHg had a sensitivity of 100 and 76.9% and a specificity of 71.1 and 67%, respectively, for the primary outcome. OP presented a significantly higher PP than pVO2 (p=0.048), whether PETCO2L didn't achieve any statistical significance (p=0.164). Pts with anOP≥31 presented a significantly lower survival free of HT during FU (log rank p=0.002).

Conclusion

OP had the highest PP for HF events of all parameters analyzed for a submaximal CPET. This parameter can help stratify the HF pts physiologically unable to reach a peak level of exercise.

Funding Acknowledgement

Type of funding source: None

Palliative care delivery according to age among metastatic breast cancer patients. ESME-MBC cohort

Background

Metastatic breast cancer (MBC) may require inpatient palliative care (IPC) but literature suggests age-related disparities in palliative care delivery. This study, based on real-world data, aimed to assess the cumulative incidence function (CIF) of IPC delivery and if age is an independent factor, taking into account the competing risk of death.

Methods

The national multicenter ESME (Epidemio-Strategy-Medical-Economical)-MBC cohort includes consecutive MBC patients treated in the 18 French Comprehensive Cancer Centers. IPC identification used ICD-10 palliative care coding. Main analysis first estimated pseudo values of 2-year and 8-year CIF of IPC. Linear regression models estimated the mean changes of pseudo-values (2 models: 2-year and 8-year CIF of IPC).

Results

Our analysis included 12375 patients, 5093 (41.2%) of whom were aged 65 or over. The median follow-up was 41.5 months (95% CI, 40.5-42.5). The CIF of IPC was 10.3% (95% CI, 10.2-10.4) and 24.8% (95% CI, 24.7-24.8) at two and eight years, respectively. At two years, among triple-negative patients, young patients (&lt;65 yo) had a higher CIF of IPC than older patients after adjusting for cancer characteristics, centre, and period (65+/&lt;65: β=-0.05; 95% CI, -0.08 to -0.01). Among other tumour subtypes, older patients received short-term IPC more frequently than young patients (65+/&lt;65: β = 0.02; 95% CI, 0.01 to 0.03). At eight years, outside large centres, IPC was delivered less frequently to older patients adjusted to cancer characteristics and period (65+/&lt;65: β=-0.03; 95% CI, -0.06 to -0.01).

Conclusions

We found a relatively low CIF of IPC and that age influenced IPC delivery. Young triple negative and older non-triple negative patients needed more short-term IPC. Older patients diagnosed outside large centres received less long-term IPC. These findings highlight the need for a wider implementation of IPC facilities and for more age-specific interventions.

Key messages

Our study highlighted particular challenge for older MBC patients diagnosed outside large French Comprehensive Cancer Centers. By identifying age at MBC diagnosis as a factor of IPC delivery, this report supports a wider implementation of IPC facilities and more age-specific interventions.

Palliative care delivery according to age in 12,000 women with metastatic breast cancer: Analysis in the multicentre ESME-MBC cohort 2008-2016

INTRODUCTION

Patients with metastatic breast cancer (MBC) often require inpatient palliative care (IPC). However, mounting evidence suggests age-related disparities in palliative care delivery. This study aimed to assess the cumulative incidence function (CIF) of IPC delivery, as well as the influence of age.

METHODS

The national ESME (Epidemio-Strategy-Medical-Economical)-MBC cohort includes consecutive MBC patients treated in 18 French Comprehensive Cancer Centres. ICD-10 palliative care coding was used for IPC identification.

RESULTS

Our analysis included 12,375 patients, 5093 (41.2%) of whom were aged 65 or over. The median follow-up was 41.5 months (95% confidence interval [CI], 40.5-42.5). The CIF of IPC was 10.3% (95% CI, 10.2-10.4) and 24.8% (95% CI, 24.7-24.8) at 2 and 8 years, respectively. At 2 years, among triple-negative patients, young patients (<65 yo) had a higher CIF of IPC than older patients after adjusting for cancer characteristics, centre and period (65+/<65: β = -0.05; 95% CI, -0.08 to -0.01). Among other tumour sub-types, older patients received short-term IPC more frequently than young patients (65+/<65: β = 0.02; 95% CI, 0.01 to 0.03). At 8 years, outside large centres, IPC was delivered less frequently to older patients adjusted to cancer characteristics and period (65+/<65: β = -0.03; 95% CI, -0.06 to -0.01).

CONCLUSION

We found a relatively low CIF of IPC and that age influenced IPC delivery. Young triple-negative and older non-triple-negative patients needed more short-term IPCs. Older patients diagnosed outside large centres received less long-term IPC. These findings highlight the need for a wider implementation of IPC facilities and for more age-specific interventions.

Abstract 3390: Predictive and prognostic value of circulating tumor DNA (ctDNA) compared to circulating tumor cells (CTC) in a prospective cohort of metastatic breast cancer patients: The UCBG COMET trial

Background: In metastatic breast cancer (MBC), monitoring circulating tumor DNA (ctDNA) can detect mutation associated with resistance to treatment and its variations reflect changes in tumor burden. We prospectively monitored CTC and ctDNA during first line chemotherapy for MBC.

Methods: The French cohort COMET is a prospective study including first line HER2- negative pts receiving weekly paclitaxel and bevacizumab. Blood samples were obtained at baseline (BL) and before the second cycle of chemotherapy (C2). ctDNA was analyzed by targeted resequencing (custom panel 220kb) SNV (28 genes + 8 promoters and CNA (18 genes).

Results: For ctDNA, out of 196 pts analyzed, 147 had at least one somatic mutation (SNV) detected in plasma (75%). Despite no complete overlap, 24 pts (12%) had no CTC nor ctDNA detected at baseline. Including Copy Number Variation analysis (CNV), the number of patients without detectable ctDNA at baseline could be reduced to 18 (9%). The average number of mutations per pt was 2.4 (range 1 to 9). Median Allelic Frequency (MAF) was 9.1%. Most commonly mutated genes were TP53 and GATA3 with 14% and 7% of all mutations, respectively. TP53 mutations were detected in 31 % of patients and were associated with a shorter progression-free and overall survival. PI3KCA mutations were detected in 23.2% of the pts, were correlated with presence of bone metastasis and had no prognostic value. ESR1 was mutated in 10.6% of the pts, restricted to the ER+ subgroup and had no impact on overall survival. At baseline, CTC and ctDNA levels were correlated (r = 0.40, p &lt; 0.0001). CTC detection was correlated with TP53 mutations detection but not with mutations PI3KCA or ESR1. Only 68 pts (36%) had detectable ctDNA at C2 with a MAF of 2% (0.3%-40%). 52.8% of patients positive for ctDNA at D1C1 became negative at D1C2 and only one negative at baseline became positive at C2.

Correlation rate with CTC was the same after one cycle of chemotherapy (r = 0.40). Median follow-up was 53 months and median OS was 32 months. At multivariate analysis, triple negative status, detectable ctDNA at C2, CTC ≥5 at C2 and grade 3 on primary tumor were independent prognostic for OS.

Conclusion: Early decrease of CTC and/or ctDNA after one cycle of chemotherapy are independent predictive markers of favorable outcome. Compared to CTC, ctDNA allows monitoring of tumor burden during chemotherapy and specific detection of targetable mutations as PI3KCA, HER2 or BRCA.

Citation Format: Jean-Yves Pierga, Amanda Silveira, Elodie Girard, Veronique Lorgis, Marie-Laure Tanguy, Benoit Albaud, Olivier Tredan, Coraline Dubot, Caroline Hego, William Jacot, Anthony Goncalves, Marc Debled, Christelle Levy, Jean-Marc Ferrero, Christelle Jouannaud, Marie-Ange Mouret-Reynier, Florence Dalenc, Sylvain Baulande, Jerome Lemonnier, Frederique Berger, Francois-Clement Bidard, Charlotte Proudhon. Predictive and prognostic value of circulating tumor DNA (ctDNA) compared to circulating tumor cells (CTC) in a prospective cohort of metastatic breast cancer patients: The UCBG COMET trial [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 3390.

Abstract 4291: VEGFA and VEGFR2 SNPs identify a subgroup of breast cancer patients with favorable outcome under Bevacizumab-based therapy - A message from COMET, a French Unicancer multicentric study

Background: Although bevacizumab (BVZ) is no longer unanimously recommended in the management of breast cancer (BRCA), few patients have shown objective benefit under BVZ treatment. We thus hypothesized that individual characteristics (germinal polymorphisms, SNPs) might help to subgroup patients drawing benefit from this therapy. We herein report confirmation of a preliminary pharmacogenetic ancillary study (ASCO 2017, abstract #1079) in the prospective COMET trial conducted on metastatic BRCA patients receiving first-line BVZ associated with paclitaxel. Both the number of patients (203 to 306) and median follow-up (24 to 50 months) were markedly increased.

Methods: Patients were enrolled in the COMET prospective cohort study from 2012 to 2015. Germinal DNA was analyzed by high-throughput genotyping in 306 patients using an 18 SNPs panel covering 7 objectively preselected genes (VEGFA, VEGFR1, VEGFR2, CYP450, CYP2C8, ABCB1, IL8). Dominant and recessive models were investigated to test possible associations between SNPs and Progression-Free Survival (PFS) and Overall Survival (OS) with a median follow-up of 50 months (CI95%: 47-57). In multivariate analysis, association between clinical characteristics, SNPs and PFS or OS was expressed as a hazard ratio (HR) with a 95% confidence interval, which was estimated using a Cox proportional-hazards model. P values ≤ 0.05 were considered statistically significant. Computational analysis using a GTEX portal was used to determine potential eQTL (expression Quantitative Trait Loci) in tissues.

Results: Median age was 55.5 (28-80), 80% ductal carcinoma, with a majority (57%) of histological grade equal to I or II. In multivariate Cox analysis, histological grade III and rs833061 C/C (VEGF-A) were associated with shorter PFS (HR= 1.7, 95%CI [1.3-2.1], p&lt;0.001; HR= 1.5, 95%CI [1.1-2.0], p=0.02 respectively). Moreover, histological grade III, rs1870377 T/T (VEGFR-2) and rs833061 C/C (VEGF-A) were associated with shorter OS (HR=1.48, 95%CI [1.10-2.0], p=0.008; HR=1.36, 95%CI [1.0-1.85], p=0.04; HR=1.69, 95%CI [1.19-2.39], p=0.002, respectively). Furthermore, for OS, a prognostic score was computed for each patient using Cox model coefficients. The estimated HR of good over poor prognosis for this model was 1.81 (95%CI [1.20-2.73], p=0.003). Median estimates were 46 and 29 months (p=0.003) for good prognosis (n=49/276) and poor prognosis (n=227/276), respectively. In silico SNP functionality analysis indicated an impact of changes on expression (rs833061) or function (rs1870377).

Conclusions: Using an easy-to-perform, low-cost genotyping test, germinal DNA identified predictors for BVZ-based treatment outcome in metastatic BRCA patients. These results open up the possibility of reconsidering BVZ treatment in a defined subgroup of BRCA patients.

Citation Format: Gerard Milano, Jocelyn Gal, Patrick Brest, Nathalie Ebran, Laurence Llorca, Coraline Dubot, Gilles Romieu, Isabelle Desmoulins, Etienne Brain, Anthony Goncalves, Jean-Marc Ferrero, Paul Cottu, Marc Debled, Olivier Tredan, Emmanuel Chamorey, Marco Carlo Merlano, Jerôme Lemonnier. VEGFA and VEGFR2 SNPs identify a subgroup of breast cancer patients with favorable outcome under Bevacizumab-based therapy - A message from COMET, a French Unicancer multicentric study [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 4291.

Risk of secondary hematologic malignancies associated with breast cancer chemotherapy and G-CSF support: A nationwide population-based cohort

Our study aimed to analyze the risk of hematologic malignancies (HM) associated with the use of G-CSF with chemotherapy for BC. Using the French National Health Data System, we examined the HM risks in patients diagnosed with an incident breast cancer between 2007 and 2015, who received chemotherapy for BC. Main outcomes were acute myeloid leukemia (AML), Myelodysplastic syndrome (MDS), myeloproliferative neoplasms (MPNs), multiple myeloma (MM), Hodgkin lymphoma or non-Hodgkin lymphoma (HL/NHL) and acute lymphoblastic leukemia or lymphocytic lymphoma (ALL/LL). Among a total of 122 373 BC survivors, 38.9% received chemotherapy only and 61.1% received chemotherapy + G-CSF. Overall, 781 cases of hematologic malignancies occurred. We observed a nonsignificant increase in the risk of AML (aHR, 1.3; 95% CI, 1.0-1.7), of MDS (aHR, 1.3; 95% CI, 0.9-1.8) and of ALL/LL (aHR, 2.0; 95% CI, 1.0-4.4) among patients treated by chemotherapy + G-CSF compared to chemotherapy only. In analyses by dose, we observed a slight increase in the risk of AML (1-3 doses: aHR, 1.2; 95% CI, 0.8-1.7/4+ doses: aHR, 1.3; 95% CI, 1.0-1.8) and of MDS (1-3 doses: aHR, 1.1; 95% CI, 0.7-1.7/4+ doses: aHR, 1.4; 95% CI, 1.0-1.9), a significant increase in risk of ALL (1-3 doses: aHR, 1.5; 95% CI, 0.5-3.9 / 4+ doses: aHR, 2.3; 95% CI, 1.0-5.1) with increasing cycles of G-CSF. Our population-based study showed that the ALL/LL was the only HM at increased risk with the use of growth factors with a possible dose-effect relationship. Our data regarding the risk of all the other HM are reassuring.

Real-world Evaluation of Oral Vinorelbine in the Treatment of Metastatic Breast Cancer: An ESME-MBC Study

BACKGROUND/AIM

Vinorelbine is indicated for use in the treatment of MBC as a single agent or in combination but there is little real world data on this molecule and even less on its oral form. We exploited the Unicancer Epidemiology Strategy Medical-Economics (ESME) metastatic breast cancer (MBC) database to investigate current patterns of use of oral vinorelbine (OV), as well as outcomes of patients receiving this drug.

PATIENTS AND METHODS

Data were collected retrospectively from women and men treated for MBC between 2008 and 2014 at one of 18 French Comprehensive Cancer Centres. The efficacy of OV was evaluated in terms of progression-free (PFS) and overall survival (OS) and treatment duration. The population and patterns of OV usage were also described.

RESULTS

A total of 1806 patients (11% of the ESME MBC database) were included in this analysis. OV was prescribed as monotherapy (46%) or in combination (29%), especially with capecitabine. mainly in later treatment lines. Median PFS was 3.3 months: 2.9 months for single agent, 3.6 months for combination therapy. Median OS was 40.9 months.

CONCLUSION

Real-world data offer complementary results to the data from traditional clinical trials, but they concern a much larger population. In this ESME MBC cohort, OV was only prescribed to a small subset of MBC patients. OV was mainly given as single agent to patients with heavily pre-treated MBC; less commonly, it was co-administered with capecitabine or anti-HER2, in earlier lines of therapy. PFS was modest but in line with previous reports.

Clinical outcome of patients experiencing central nervous system progression on first-line pertuzumab and trastuzumab for HER2-positive metastatic breast cancer in a real-life cohort

2527

Background: Isolated central nervous system (CNS) progression on first-line systemic therapy with Trastuzumab (T) and Pertuzumab (P) for HER2-positive metastatic breast cancer (MBC) is a therapeutic challenge. Our aim was to describe the clinical outcome and current treatment strategies for such patients in a large retrospective cohort. Methods: Patients (pts) were selected among all MBC pts included in the French Epidemiological Strategy and Medical Economics (ESME) database involving 18 specialized cancer centers (NCT03275311). CNS progression-free survival (CNS-PFS), progression-free survival (PFS) and overall survival (OS) from diagnostic of brain metastases (BM) were estimated using the Kaplan-Meier method. Results: Between January 2008 and December 2016, 995 pts were treated with first-line T and P for their HER2-positive MBC. They were 55 years old in median, with tumors expressing hormone-receptors in 62%. A total of 132 pts (13%) experienced isolated CNS progression on T and P, with a median time from metastatic diagnosis to CNS progression of 12 months. It was the first CNS progression for 108 pts (82%) while 24 (18%) already had BM at time of metastatic relapse. After CNS progression, T and P were continued for 58% of pts (n = 73). The remaining 47 pts were switched to another HER2-directed therapy (T-DM1 for 57%, T alone or combined with chemotherapy for 36% and lapatinib for 21%). Among those 132 pts, 37% received whole-brain radiotherapy, 18% stereotactic radiation therapy, and 11% surgery. Systemic treatment was combined with CNS-directed therapy for 50% of pts. Median follow-up is 21 months (95%CI: 14.9-25.5) from the diagnosis of CNS metastases. Median OS (mOS) of the 132 pts is 35 months (95%CI: 29.2-53,6), and median PFS 7 months (95%CI: 6.3- 9.2). A total of 77 pts (58.3%) experienced a new CNS progression with a median CNS-PFS of 9 months (95%CI: 7.6-12,0). Patient who stayed on T and P had a significantly better OS in comparison to pts who were switched to another systemic HER2-directed therapy (mOS not evaluable vs23 months), whereas PFS and CNS-PFS were similar between groups. Conclusions: In this real life setting, isolated CNS progression occurred among 13% of pts with HER2+ MBC on first-line treatment with T and P, after a median time of 12 months. Following current ASCO recommendations, continuation of T and P after CNS-directed therapy, seemed to be adequate. Nevertheless, time to subsequent progression is short and better therapeutic options are needed.

Clinical activity of MCLA-128 (zenocutuzumab) in combination with endocrine therapy (ET) in ER+/HER2-low, non-amplified metastatic breast cancer (MBC) patients (pts) with ET-resistant disease who had progressed on a CDK4/6 inhibitor (CDK4/6i)

1037

Background: MCLA-128 (zenocutuzumab) is an ADCC-enhanced humanized bispecific antibody targeting HER2 and HER3 and potently blocking HER3-ligand induced receptor dimerization. Upregulation of Her2:Her 3 pathway is a means of resistance to ET in HR+ breast cancer, indicating a potential role for MCLA-128. In preclinical studies, the combination of MCLA-128 with ET in breast cancer xenografts outperformed single drug treatments. The current study explores the use of MCLA-128 to rescue pts with ET-resistant MBC who have progressed on a CDK4/6i. Methods: This phase II, open-label trial planned for up to 40 evaluable women with HR+, HER2 low (IHC 1+/IHC 2+ with negative FISH) MBC, who had progressed on a CDK4/6i and up to 3 lines of ET, who had received ≤ 2 chemotherapy regimens in the metastatic setting. Pts received MCLA-128 (750 mg, 2h IV, flat dose) q3w combined with last ET on which the pt had previously progressed immediately prior to study entry. Disease control rate (DCR; RECIST 1.1, per investigator), best overall response (BOR), overall response rate (ORR), safety, and PK, are evaluated. Data cut off was 14Nov2019. Results: 48 pts were treated, all of whom had progressed on a CDK4/6i. Pts had received a median 2 prior ET lines (range 1-5) and 1 line (range 1-3) of chemotherapy. Pts had a median number of 3 metastatic sites (range 1-6) and 42 (88%) had visceral involvement. Among 42 pts evaluable for efficacy, DCR was 45% (90% CI 32-59) with 2 pts having unconfirmed PR and 19 pts SD as BOR. Common related AEs (all grades; G3-4) were asthenia/fatigue (27%; 2%), diarrhea (25%; 0), nausea (21%; 0). No clinically significant LVEF decline was seen. At the end of cycle 1, mean trough level of MCLA-128 was 15.5 µg/mL, and mean terminal half-live was 102 h (n = 19-21). Data on the primary endpoint, clinical benefit rate at 24 weeks, and biomarkers will be provided. Conclusions: The addition of MCLA-128 to the last line of ET showed clinical activity after ET+CDK4/6i failure and a favorable safety profile. Clinical trial information: NCT03321981 .

Clinical activity of MCLA-128 (zenocutuzumab), trastuzumab, and vinorelbine in HER2 amplified metastatic breast cancer (MBC) patients (pts) who had progressed on anti-HER2 ADCs

3093

Background: MCLA-128 (zenocutuzumab ), a HER3 pathway inhibitor, is a humanized bispecific full-length IgG1 antibody targeting both HER2 and HER3 with enhanced ADCC activity. The unique Dock & Block mechanism inhibits HER3 from interacting with its ligands and targets HER2 at a different epitope than trastuzumab, blocking HER2/HER3 dimerization and downstream PI3K/AKT/mTOR signaling. In MBC, HER3 overexpression and/or HER3 ligand upregulation are important drivers leading to trastuzumab resistance, indicating a role for MCLA-128. Preclinical activity was seen in HER2+ breast models when MCLA-128 was combined with trastuzumab. Furthermore, single agent MCLA-128 showed consistent antitumor activity in heavily pretreated HER2+ MBC pts. A phase 2, open-label study explored the MCLA-128/trastuzumab plus vinorelbine triplet in an MBC population. Methods: This open-label trial planned for up to 40 evaluable women with HER2+/amplified MBC progressing on up to 5 anti-HER2 lines including trastuzumab, pertuzumab and an anti-HER2 ADC. Pts received MCLA-128 (750 mg, 2h IV), trastuzumab (8 mg/kg loading, then 6 mg/kg) and vinorelbine (25 mg/m², D1 and 8), q3w. A safety run-in of MCLA-128 + trastuzumab ± chemotherapy was performed. Disease control rate (DCR; RECIST 1.1, per investigator), best overall response (BOR), overall response rate (ORR), safety, and PK are evaluated. Data cutoff was 14Nov2019. Results: 28 pts with a median 3 lines (range 2-5) of anti-HER2 therapy (metastatic setting) and 3 (range 1-6) metastatic sites, received a median of 5 (range 1-17) MCLA-128 cycles. Among 26 pts evaluable for efficacy, 20 patients had CR/PR/SD as BOR; DCR was 77% (90%CI: 60-89) with 1 confirmed CR and 4 PRs (2 unconfirmed). Common related AEs (all grades; G3-4) were neutropenia/neutrophil count decrease (61%; 46%), diarrhea (61%; 4%), asthenia/fatigue (46%; 0), nausea (29%; 0). No clinically significant LVEF decline was seen. At the end of cycle 1, mean trough levels of MCLA-128 was 19.1 µg/mL, and mean terminal half-life was 112 h (n = 8-11). Data on the primary endpoint, clinical benefit rate at 24 weeks, and biomarkers will be provided. Conclusions: The triplet MCLA-128-based combination is active in heavily pretreated pts with HER2+/amplified MBC. The regimen is safe and well tolerated with a manageable AE profile mostly related to the chemotherapy component. Clinical trial information: NCT03321981 .

Soluble BTN2A1 as a potential predictive biomarker of immune checkpoint inhibitor efficacy in advanced non-small cell lung cancer (NSCLC)

9561

Background: Medical treatment of lung cancer has irreversibly changed since the development of immune checkpoint inhibitors (ICI). However, immune biomarkers of efficacy are still lacking. Preliminary data in leukemia and pancreatic cancer showed that soluble immune checkpoints are associated with a reduced overall survival (OS). This led us to explore the prognostic and predictive value of soluble immune checkpoints in non-small cell lung cancer (NSCLC) patients treated with chemotherapy or ICI. Methods: We analyzed 90 advanced NSCLC patients. The pilot cohort (Rennes University Hospital, France), included 48 patients treated with platinum doublets (n = 33) or ICI (n = 15) (LOC/11-16 protocol). The confirmation cohort (Paoli-Calmettes Institute) included 42 patients treated with ICI (nivolumab or pembrolizumab) in a longitudinal prospective setting (Immunosup trial, NCT03595813). In both cohorts, enzyme-linked immunosorbent assays (ELISA) were performed in baseline plasma samples for soluble forms of PD-1, PD-L1, global BTN3, BTLA, BTN3-A1 and BTN2A1. Soluble ICI levels were linked to clinical data using Kaplan-Meier, log-rank and Cox proportional-hazards models. Cut-points were determined using maxstat package for survival, R software R 3.6.2. Results: Five soluble immune checkpoints correlated and clustered together in unsupervised analysis (PD-1, PD-L1, global BTN3, BTLA, BTN3-A1), but were not associated with ICI efficacy. In patients treated with ICI, in the pilot and confirmation cohort, a high baseline plasmatic concentration of soluble BTN2A1 was significantly associated with an improved OS (confirmation cohort with a BTN2A1 cut-point of 3.55 ng/ml: HR = 0.30, 95%CI = 0.12-0.74, p = 0.0057, median OS in BTN2A1low = 7.6 months and median OS in BTN2A1hi = 19.5 months). On the contrary, in patients treated with chemotherapy, soluble BTN2A1 concentration was not associated with overall survival. Conclusions: In advanced NSCLC patients, a high baseline plasmatic concentration of soluble BTN2A1 was correlated with improved outcomes for ICI, but not for chemotherapy, suggesting that baseline soluble BTN2A1 level is a potential predictive biomarker of ICI efficacy. Additional studies are ongoing to confirm this finding.

Association of tumor mutational burden (TMB) and clinical outcomes with pembrolizumab (pembro) versus chemotherapy (chemo) in patients with metastatic triple-negative breast cancer (mTNBC) from KEYNOTE-119

1013

Background: In the randomized, open-label, phase 3 KEYNOTE-119 study (NCT02555657) , OS was not significantly different with pembro monotherapy versus chemo in second- or third-line settings for mTNBC; however, the pembro treatment effect increased with increasing PD-L1 enrichment. We evaluated the association of TMB with efficacy of pembro monotherapy versus chemo in patients with previously treated mTNBC. Methods: Patients with centrally confirmed TNBC and 1 or 2 prior systemic treatments for metastatic disease were enrolled. Patients were randomly assigned 1:1 to pembro 200 mg Q3W or single-agent chemo per investigator’s choice of capecitabine, eribulin, gemcitabine, or vinorelbine. Association of TMB, as measured by FoundationOne CDx (Foundation Medicine), with response was an exploratory objective evaluated using receiver operator characteristic (ROC) analysis, logistic regression (ORR), and Cox regression (OS; PFS) within treatment arms; estimates of efficacy based on TMB cutpoint used a prespecified cutpoint of 10 mut/Mb. Results: TMB data were available for 253/601 (42.1%) treated patients (pembro, n = 132; chemo, n = 121); baseline characteristics were similar to that of the overall study population. One-sided P values for the association of TMB and clinical outcomes in pembro-treated patients were 0.154 for ORR, 0.014 for PFS, and 0.018 for OS; the area under the ROC curve ([AUROC] 95% CI) for predicting ORR was 0.58 (0.43-0.73). Two-sided P values for the association of TMB and clinical outcomes in chemo-treated patients were 0.114 for ORR, 0.478 for PFS, and 0.906 for OS; AUROC (95% CI) was 0.43 (0.27-0.59). Twenty-six patients had TMB ≥10 mut/Mb. Thus, the prevalence of TMB ≥10 mut/Mb was ~10%. Outcomes based on TMB cutpoint are reported in the Table. Conclusions: Data from this exploratory analysis from KEYNOTE-119 suggest a potential positive association between TMB and clinical benefit with pembro but not chemo in patients with mTNBC. Although precision is limited by sample size and the number of patients with TMB ≥10 mut/Mb, ORR and HRs for OS suggested a trend towards increased benefit with pembro versus chemo in patients with TMB ≥10 mut/Mb. Clinical trial information: NCT02555657 . [Table: see text]

The therapeutic response of ER+/HER2- breast cancers differs according to the molecular Basal or Luminal subtype

The genomics-based molecular classifications aim at identifying more homogeneous classes than immunohistochemistry, associated with a more uniform clinical outcome. We conducted an in silico analysis on a meta-dataset including gene expression data from 5342 clinically defined ER+/HER2- breast cancers (BC) and DNA copy number/mutational and proteomic data. We show that the Basal (16%) versus Luminal (74%) subtypes as defined using the 80-gene signature differ in terms of response/vulnerability to systemic therapies of BC. The Basal subtype is associated with better chemosensitivity, lesser benefit from adjuvant hormone therapy, and likely better sensitivity to PARP inhibitors, platinum salts and immune therapy, and other targeted therapies under development such as FGFR inhibitors. The Luminal subtype displays potential better sensitivity to CDK4/6 inhibitors and vulnerability to targeted therapies such as PIK3CA, AR and Bcl-2 inhibitors. Expression profiles are very different, showing an intermediate position of the ER+/HER2- Basal subtype between the ER+/HER2- Luminal and ER- Basal subtypes, and let suggest a different cell-of-origin. Our data suggest that the ER+/HER2- Basal and Luminal subtypes should not be assimilated and treated as a homogeneous group.

Contemporary outcomes of metastatic breast cancer among 22,000 women from the multicentre ESME cohort 2008-2016

AIM

Real-world data inform the outcome comparisons and help the development of new therapeutic strategies. To this end, we aimed to describe the full characteristics and outcomes in the Epidemiological Strategy and Medical Economics (ESME) cohort, a large national contemporary observational database of patients with metastatic breast cancer (MBC).

METHODS

Women aged ≥18 years with newly diagnosed MBC and who initiated MBC treatment between January 2008 and December 2016 in one of the 18 French Comprehensive Cancer Centers (N = 22,109) were included. We assessed the full patients' characteristics, first-line treatments, overall survival (OS) and first-line progression-free survival, as well as updated prognostic factors in the whole cohort and among the 3 major subtypes: hormone receptor positive and HER2-negative (HR+/HER2-, n = 13,656), HER2-positive (HER2+, n = 4017) and triple-negative (n = 2963) tumours.

RESULTS

The median OS of the whole cohort was 39.5 months (95% confidence interval [CI], 38.7-40.3). Five-year OS was 33.8%. OS differed significantly between the 3 subtypes (p < 0.0001) with a median OS of 43.3 (95% CI, 42.5-44.5) in HR+/HER2-; 50.1 (95% CI, 47.6-53.1) in HER2+; and 14.8 months (95% CI, 14.1-15.5) in triple-negative subgroups, respectively. Beyond performance status, the following variables had a constant significant negative prognostic impact on OS in the whole cohort and among subtypes: older age at diagnosis of metastases (except for the triple-negative subtype), metastasis-free interval between 6 and 24 months, presence of visceral metastases and number of metastatic sites ≥ 3.

CONCLUSIONS

The ESME program represents a unique large-scale real-life cohort on MBC. This study highlights important situations of high medical need within MBC patients. DATABASE REGISTRATION: clinicaltrials.gov Identifier NCT032753.

Abstract P1-19-19: Treatments and outcome in older versus younger women with HER2-positive metastatic breast cancer in the multicenter national observational ESME database

Background: Prognosis of women with HER2+ metastatic breast cancer (MBC) has radically improved over the past 10 years, resulting from the implementation in clinical of anti-HER2 therapies. However, there are limited data regarding these trends in the older women, although they represent a growing segment of the population. Standard strategy being based mostly on combinations of anti-HER2 treatments with chemotherapy, under-treatment may be a specific issue in this population.

Methods: Based on the ESME MBC Data Platform (NCT03275311),a unique national real-life database including individual data from all patients (pts) ≥18 years who initiated a first-line treatment for MBC between 2008 and 2016 in the 18 French Comprehensive Cancer Centers, the main objective of this work was the description of patients’ outcome in women with HER2+ MBC according to age: ≥70 vs &lt;70. Secondary objective included the description of treatment patterns and a multivariate analysis. Outcome was described with overall survival (OS) and progression-free survival (PFS). Variables of interest were age (≥70 vs &lt; 70), number of metastatic sites at initial MBC diagnosis (1 vs 2 vs ≥3), visceral disease (Y/N), hormone receptor status (HR+/HR-), de novo MBC (Y/N), type of first-line treatment. We relied on Cox’s proportional hazard (PH) model, with adjustment for non-PH in the presence of time-varying effects; hazard ratios (HR) with 95% confidence interval were reported (IC95%).

Results: Of 22463 cases selected, 4045 (18%) women had HER2+ MBC with a 4.4-year median follow-up. Of those, 814 (20%) were aged ≥ 70 and had more often HR+ disease (Table 1). As 1st line treatment, anti-HER2 therapy was prescribed in 76% vs 92% of older vs younger pts, combined with chemotherapy in 65% vs 89%. Median OS and PFS (years) were 2.9 [2.6-3.1] and 0.9 [0.8 - 1.0] vs 4.5 [4.2-4.6] and 1.1 [1.1-1.2] in older vs younger patients. Multivariate analysis for OS identified the following variables as significant: age ≥ 70 (HR=1.57 IC95% [1.40-1.75]), 2 and ≥ 3 metastatic sites (HR=1.24 IC95% [1.10-1.39] and HR=1.92 IC95% [1.70-2.17] respectively), de novo MBC (HR 0.70 IC95% [0.63 - 0.77]), visceral disease with a time-varying effect (HR=2.67 IC95% [2.11-3.39] and 5.98 IC95% [4.64-7.46] at 1 and 5 years) and first-line treatment with a time-varying effect, better prognosis for combination of chemotherapy + anti-HER2 agent + endocrine therapy vs any other. Except for de novo MBC, similar results were observed for PFS.

Conclusions: In this large real-life database, older HER2+ MBC patients received significantly less frequently “standard” first-line anti-HER2 treatment, defined as a combination of chemotherapy and anti-HER2 treatment. Age was a strong risk factor for both PFS and OS. Given the lack of information on geriatric assessment (e.g. general health status, functional status, comorbidity, etc.), confounding factors and usual selection biases cannot be ruled out. These results stress the importance to study older populations with specific approaches, not based on the usual transfer of those developed in younger ones, in order to avoid under and overtreatments, both that are not acceptable.

Table 1: Patients’ characteristics and first-line treatment≥70&lt;70AllP value N814 (20%)3231 (80%)4045 (100%)NAAge at MBC diagnosis (years)median775357NAQ1-Q373-8245-6047-67HR+ (≥10%)Yes560 (69%)2034 (63%)2594 (64%)0.01No247 (30%)1167 (36.1%)1414 (35%)missing7 (1%)30 (1%)37 (1%)De novo MBCYes310 (38%)1310 (41%)1620 (40%)0.20No503 (62%)1915 (59%)2418 (60%)missing1 (0%)6 (0%)7 (0%)Number of metastatic sites1429 (53%)1670 (52%)2099 (52%)0.902211 (36%)834 (26%)1045 (26%)3+170 (21%)696 (21%)866 (21%)missing4 (0%)31 (1%)35 (1%)Visceral diseaseYes510 (63%)2096 (65%)2606 (64%)0.18No300 (37%)1104 (34%)1404 (35%)Missing4 (0%)31 (1%)35 (1%)Chemotherapy + anti-HER2 agent as 1st line treatmentYes529 (65%)2880 (89%)3409 (84%)&lt;0.01No241 (30%)296 (9%)537 (13%)Missing44 (5%)55 (2%)99 (2%)Anti-HER2 agent as 1st line treatmentYes623 (76%)2984 (92%)3607 (89%)&lt;0.01No147 (18%)192 (6%)339 (8%)Missing44 (6%)55 (2%)99 (3%)

Citation Format: Mylène Annonay, Morgane Abiven, Etienne Brain, Mony Ung, Laurence Cristol-Dalstein, Marie-Ange Mouret-Reynier, Anthony Goncalves, Sophie Abadie-Lacourtoisie, Eric Francois, Claudia Lefeuvre-Plesse, Johann Le Fel, Veronique Lorgis, Veronique Servent, Lionel Uwer, Christelle Jouannaud, Marianne Leheurteur, Loic Campion, Coralie Courtinard, Olivier Villacroux, Thierry Petit, Pierre Soubeyran, Thomas Bachelot, Carine Bellera, Suzette Delaloge. Treatments and outcome in older versus younger women with HER2-positive metastatic breast cancer in the multicenter national observational ESME database [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P1-19-19.

Abstract P2-19-01: Impact of bone-only metastatic breast cancer on outcome in a real-life setting: A comprehensive analysis of 5,041 women from the ESME database

Background: Bone-only (BO) metastatic breast cancer (MBC), defined as bone as unique site of metastasis at MBC diagnosis, is thought to carry a better prognosis among MBC. However, only small retrospective series and data from selected randomized controlled trials have been reported so far. Based on a national database, we aimed at providing a large comprehensive analysis of BO MBC, and at evaluating its impact on clinical outcome.

Methods: The ESME MBC platform (NCT03275311) is a French multicenter retrospective real-life database using a clinical trial-like methodology to collect data from 18 French Comprehensive Cancer Centers. It includes data from each newly diagnosed MBC patient having initiated at least one treatment between 2008 and 2016. BO cases occurring in women were retrieved and compared to the overall non-BO population, regarding treatment effects and survival.

Results: Of the 22,463 women selected in the database, 5,041 (22.4%) patients with BO disease were identified. Most (N=4,102, 81.4%) had HR+/HER2- disease while 644 (12.8%) and 295 (5.9%) patients had HER2+ or HR-/HER2- disease, respectively. Compared to non-BO MBC, BO MBC patients were older in the global cohort and in HR-/HER2- patients (mean age 61.0y versus 59.5y, and 59.3y vs 56.4y, all p&lt;0.0001, respectively), and tumor histology was more frequently a lobular carcinoma in the global cohort, in HR+/HER2- and in HR-/HER2- patients (18.6% vs 10.8%, 20.6% vs 15.2%, 13.8% vs 3.2%, all p&lt;0.0001, respectively). In addition, metastatic disease occurred de novo more frequently in BO MBC patients (37.9% versus 29.2%) (p&lt;0.0001), and a statistically significant difference was also observed within each tumor subtype group. The management of bone disease included bisphosphonates or denosumab, radiotherapy, and invasive bone metastasis procedures in 3,913 (77.6%), 2,929 (58.1%), and 1,154 (22.9%) patients, respectively. Median follow up was 52.4 months (95% CI [50.8-54.2]) in BO population and 50.9 months (95% CI [49.7-51.8]) in non-BO population. BO MBC patients had improved median progression-free survival (PFS) 1, regarding first-line treatment, and overall survival (OS) compared to non-BO MBC, globally and within each tumor subtype group (Table). Indeed, 5-year OS rates reached up to 43%, 54% and 16% in HR+/HER2-, HER2+ and HR-/HER2- BO MBC groups, respectively. This suggests that a substantial number of these patients could be considered as long survivors. In the BO MBC cohort, de novo BO MBC patients had a higher 5-year OS rate than relapsed BO MBC patients. BO disease was an independent prognostic factor of OS (hazard ratio 0.68 (95% CI [0.65-0.72]), p&lt;0.0001) together with age, tumor subtype, grade, adjuvant treatment and metastatic-free interval.

Conclusion: This large comprehensive study is the largest cohort of BO MBC to date. BO MBC has a distinct presentation from non-BO MBC and carry a better prognosis compared to non-BO MBC. A significant proportion of BO MBC patients have a very long survival and may benefit from aggressive local therapy, as stereotactic radiotherapy. Dedicated studies are warranted to tailor the management of these patients.

Funding: This work was supported by UNICANCER. The ESME MBC database is supported by an industrial consortium (Roche, Pfizer, AstraZeneca, MSD, Eisai and Daiichi Sankyo). Data collection, analyses and publications are totally managed by R&D UNICANCER independently of the industrial consortium.

TableBOBOBOBOnon-BOnon-BOnon-BOnon-BON (%)median OS monthsmedian PFS1 months5-year OS rate %N (%)median OS monthsmedian PFS1 months5-year OS rate %(95% CI)(95% CI)(95% CI)(95% CI)(95% CI)(95% CI)Overall population5,041 (100%)52.1 (50.3-54.1) 13.1 (12.6-13.8) 43.41 (41.66-45.15)15,054 (100%)34.7 (34.0-35.6) 8.5 (8.3-8.7) 30.55 (29.62-31.48)HR+/HER-4,102 (81.4%)52.6 (50.5-54.8)13.6 (13.0-14.3)43.52 (41.56-45.46)9,127 (60.6%) 39.0 (37.8-40.1)9.6 (9.3-9.9)32.69 (31.47-33.93)HER2+644 (12.8%)66.4 (59.8-71.9) 14.9 (12.9-17.3) 54.49 (49.54-59.16)3,265 (21.7%) 46.5 (44.2-48.9)10.6 (10.1-11.3)39.88 (37.77-41.98)HR-/HER2-295 (5.9%)20.8 (18.3-27.4) 5.6 (4.9-7.5)16.21 (11.21-22.02)2,662 (17.7%) 14.3 (13.6-15.1)4.8 (4.6-5.0)10.89 (9.4-12.5)De novo MBC patients1,909 (37.9%)58.6 (55.4-62.1)17.9 (17.0-18.9)48.24 (45.28-51.14)4,399 (29.2%) ---Relapsed MBC patients3,132 (62.1%)48.3 (46.5-50.5)10.7 (10.2-11.2)40.51 (38.34-42.67)10,655 (70.8%)---

Citation Format: Marion Bertho, Julien Fraisse, Anne Patsouris, Paul Cottu, Suzette Delaloge, David Pérol, Anne Jaffré, Anthony Goncalves, Marie-Paule Lebitasy, Véronique D'Hondt, Florence Dalenc, Jean-Marc Ferrero, Christelle Levy, Patrick Arveux, Roman Rouzier, Frédérique Penault-Llorca, Lionel Uwer, Jean-Christophe Eymard, Mathias Breton, Michaël Chevrot, Marianne Leheurteur, Michel Velten, Gaëtane Simon, Jean-Sébastien Frenel. Impact of bone-only metastatic breast cancer on outcome in a real-life setting: A comprehensive analysis of 5,041 women from the ESME database [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P2-19-01.

High spatial resolution inorganic scintillator detector for high-energy X-ray beam at small field irradiation

Purpose

Small field dosimetry for radiotherapy is one of the major challenges due to the size of most dosimeters, for example, sufficient spatial resolution, accurate dose distribution and energy dependency of the detector. In this context, the purpose of this research is to develop a small size scintillating detector targeting small field dosimetry and compare its performance with other commercial detectors.

Method

An inorganic scintillator detector (ISD) of about 200 µm outer diameter was developed and tested through different small field dosimetric characterizations under high‐energy photons (6 and 15 MV) delivered by an Elekta Linear Accelerator (LINAC). Percentage depth dose (PDD) and beam profile measurements were compared using dosimeters from PTW namely, microdiamond and PinPoint three‐dimensional (PP3D) detector. A background fiber method has been considered to quantitate and eliminate the minimal Cerenkov effect from the total optical signal magnitude. Measurements were performed inside a water phantom under IAEA Technical Reports Series recommendations (IAEA TRS 381 and TRS 483).

Results

Small fields ranging from 3 × 3 cm², down to 0.5 × 0.5 cm² were sequentially measured using the ISD and commercial dosimeters, and a good agreement was obtained among all measurements. The result also shows that, scintillating detector has good repeatability and reproducibility of the output signal with maximum deviation of 0.26% and 0.5% respectively. The Full Width Half Maximum (FWHM) was measured 0.55 cm for the smallest available square size field of 0.5 × 0.5 cm², where the discrepancy of 0.05 cm is due to the scattering effects inside the water and convolution effect between field and detector geometries. Percentage depth dose factor dependence variation with water depth exhibits nearly the same behavior for all tested detectors. The ISD allows to perform dose measurements at a very high accuracy from low (50 cGy/min) to high dose rates (800 cGy/min) and was found to be independent of dose rate variation. The detection system also showed an excellent linearity with dose; hence, calibration was easily achieved.

Conclusions

The developed detector can be used to accurately measure the delivered dose at small fields during the treatment of small volume tumors. The author's measurement shows that despite using a nonwater‐equivalent detector, the detector can be a powerful candidate for beam characterization and quality assurance in, for example, radiosurgery, Intensity‐Modulated Radiotherapy (IMRT), and brachytherapy. Our detector can provide real‐time dose measurement and good spatial resolution with immediate readout, simplicity, flexibility, and robustness.

1185 Three-dimensional speckle tracking echocardiography for the global and regional assessment of myocardial deformation in breast cancer patients submitted to anthracyclines

Introduction

Serial echocardiographic assessment of 2D/3D left ventricular ejection fraction (LVEF) and 2D global longitudinal strain (GLS) is the gold standard for screening for cancer therapeutics-related cardiac dysfunction (CTRCD). Although 3D speckle tracking echocardiography (STE) has several technical advantages, is more reproducible, and has a better correlation to magnetic resonance than 2D STE, it is still not currently used in this setting. We aimed to investigate the usefulness of 3D STE in evaluating left ventricle mechanics and its relation to CTRCD.

Methods

Prospective study of female breast cancer patients submitted to anthracycline chemotherapy who underwent one transthoracic echocardiography (ETT) before and at least one ETT during/after chemotherapy. Standard ETT parameters and 3D volumetric measurements were assessed. STE was used to estimate 2D GLS – average and 18 segments – and 3D GLS, global circumferential strain (GCS), global radial strain (GRS) and global area strain (GAS) – average and 17 segments. CTRCD was defined as an absolute decrease in 2D or 3D LVEF &gt;10% to a value &lt;54% or a relative decrease in 2D GLS &gt;15%.

Results

105 patients (mean age 53.8 ± 12.5 years, 52.4% immunotherapy, 77.2% radiotherapy, 2.8 echocardiograms/patient) were included. During a mean follow-up of 12.1 months, 24 patients (22.9%) developed CTRCD. During anthracycline therapy, there was a significant worsening of 2D LVEF (65.6 vs. 57.8), 3D LVEF (61.5 vs. 54.4), 2D GLS (-21.1 vs. -18.0), 3D GLS (-15.6 vs. -10.9), 3D GCS (-14.0 vs. -11.0), 3D GRS (42.0 vs. 28.5) and 3D GAS (-27.0 vs. -20.0) [all p &lt;0.001]. More than 73% of patients presented 3D global strain values below the limits of normal during chemotherapy. On 3D strain regional analysis, impaired contractility was observed in the anterior, inferior and septal walls. Logistic regression analysis showed that 3D GRS and 3D GCS were associated with a higher incidence of CTRCD. In the multivariate model, 3D GRS remained the only independent predictor of CTRCD. The receiver operating curve analysis showed a good calibration and discrimination of 3D GCS and 3D GRS in predicting CTRCD with areas under de curve of 0.748 and 0.719, with the optimal cut-off values being 0.342 for GCS and 0.344 for GRS. These variations were observed a median of 45 days and 22.5 days before the diagnosis of CTRCD, respectively.

Conclusion

3D strain parameters worsened during anthracycline therapy, with predominant involvement of septal, anterior and inferior walls. Variations of 3D GCS and GRS were predictive of subsequent CTRCD, and thus can be considered an earlier sign of CTRCD, with added value over the currently recommended 2D/3D LVEF and 2D GLS. Routine application of this technique should be considered in order to offer targeted monitoring and timely initiation of cardioprotective treatment.

P1527 Papillary fibroelastomas: diagnostic challenges and clinical and morphologic features

Introduction

Papillary fibroelastomas are rare benign primary cardiac tumors that more frequently involve cardiac valves. They are frequently incidentally discovered by echocardiography but may also cause symptoms.

Purpose

The aim of this study was to characterize several features of histologically confirmed fibroelastomas.

Methods

Retrospective analysis of patients with echocardiographic suspicion of fibroelastoma between 2009 and 2019 in a single tertiary center. Echocardiography was compared with histology, and echocardiographic, surgical and pathological information about confirmed fibroelastomas was collected.

Results

37 patients (P) (54.1% men) with an echocardiographic suspicion and/or histologically confirmed fibroelastoma were included, with a mean age of 58 +- 3 years (min 22, max 82). Echocardiographic report was analyzed in 34P (91.9%), with 32P (94.1%) reporting a likely fibroelastoma and 2P (5.9%) reporting a non-specified mass. 21P (56.8%) had surgery, with 12P (57.1%) having a surgical suspicion of a fibroelastoma, 2P (9.5%) of a mixoma, 1P (4.8%) of a non-specified mass and 6P (28.6%) with undefined suspicion. Of the 21P who had surgery, 66.7% (14P) had a histologically confirmed fibroelastoma, 1P (4.8%) had a mixoma, and 6P (28.6%) had other diagnoses. From the 14P with histologically confirmed fibroelastoma 64.3% had this suspicion by echocardiography and 35.7% had an echocardiogram reporting a non-specified. There was a global concordance between echocardiography and histology in 52.9%. The mean age of confirmed fibroelastoma P was 54 +-5years, and 50% were men. 7P (50%) were asymptomatic, 2 (14.3%) had a stroke, 2 (14.3%) had syncope, 1 (7.1%) had fatigue, 1 (7.1%) had palpitations and 1P had consciousness alteration. In echocardiography most P (71.4%) had only one mass but 1P had 4 different masses. The tumors had a longer axis between 6 and 25mm, with the majority (57.1%) measuring more than 10mm. 12P (85.7%) had valvular fibroelastomas, 50% of these in the aortic valve (3 in non-coronary cusp, 1 in right coronary cusp and 2 non-specified) and 50% in the mitral valve (all in sub-valvular apparatus, involving anterior leaflet, tendinous chord or papillary muscle). 1P had a left ventricular fibroelastoma (apical) and 1P had four masses in the left atrium. Macroscopically 4 lesions had a gelatinous consistency, 2 of them were membranous, 2 were elastic, 2 were friable, 1 was villainous and in 3 of them consistency was not described. The majority (57%) was white, 14% was translucent and in the rest the color was not specified. There was no described recurrence after surgery and there were no deaths registered.

Conclusion

In this population there was a reasonable concordance between echocardiography and histology, but in some cases the diagnosis was undefined or wrong. 50% of the patients were asymptomatic and the majority had valvular fibroelastomas, but a few had a different location.

P1349 POCUS by general and family physician - advancing physical examination

BACKGROUND

Alongside with the development of hand held equipment, echo is becoming more accessible to nontraditional settings. General and family medicine (GPs) are at the forefront of any health system, but the use of cardiac echo by GPs is still unexplored. PURPOSE: This study aims to evaluate the accuracy of echocardiography assessment performed as an extension of the physical exam by GPs. METHODS: Two GPs underwent standard echocardiography training for 6 months. Subsequently, patients with diabetes or arterial hypertension were submitted to an echocardiogram performed by their GPs using a pocket ultrasound. Views obtained (with and without color Doppler) were parasternal long and short axis, apical and subcostal, with measurements of the posterior wall (PW), interventricular septum (IVS), left ventricle (LV), left atrium (LA), aorta and inferior vena cava (IVC). Studies were reviewed at the workstation and measured by two experts who classified the exams according to the image quality. RESULTS: Sixty echocardiograms were analyzed (mean age of 61y, 42% females and 58% males). In 50% the image quality was considered sufficient, 42% considered good and 8% considered bad. There were statistically significant differences between the GPs and expert measurements on the sinus of Valsalva (30.3 ± 3 to 28.8 ± 3.1mm, p = 0.001), LV in systole (p &lt; 0.001, 28[24,31] for 31[29,34]mm), IVS (p = 0.001, 10.9 ± 1.7 for 10.1 ± 1.5mm), PW (p = 0.018, 8.7 ± 1.1 to 9.2 ± 1.6mm) and TAPSE (p = 0.021, 20.9 ± 2.3 to 20.1 ± 2.7mm). There were no significate differences in the measurements of the ascending aorta, LA, LV in diastole and IVC. Agreement between the GPs and the experts was moderate for the evaluation of LVH (k = 0.48). The concordance was substantial for evaluation of LV function (k = 0.66) and excellent for evaluation of pericardial effusion (k = 1) and right ventricular function (k = 1). Concordance was excellent for mitral insufficiency (k = 0.83) and substantial for aortic insufficiency (k = 0.68) and tricuspid insufficiency (k = 0.61). A case of mitral stenosis was identified by both. GPs signalized a case of mild aortic stenosis that the expert did not consider. CONCLUSION: GPs trained in echocardiography, using pocket ultrasound, can obtain cardiac images with sufficient quality for interpretation by experts in the majority of cases. In this study, differences in dimensions might be explained by interobserver variability and/or by the performance of measurements in different environments, mobile vs workstation. Overall the differences were minor and clinically meaningless.

100 Association of age-related left atrial remodeling with ischemic stroke in patients with normal sinus rhythm

OnBehalf

The ARIC Study

Background

Age-related left atrial (LA) structural/functional abnormalities in elderly patients with normal sinus rhythm and preserved ejection fraction may precede the development of overt atrial fibrillation, and also may be related to stroke.

Purpose

To evaluate the association of 3-dimensional echocardiographic (3DE) atrial contractility parameters with subclinical cerebral infarcts (SCIs), as assessed by brain MRI, and clinically diagnosed stroke

Methods

We studied 407 participants (mean age 76 ± 5 years, 40.5% male) from the Atherosclerosis Risk in Communities Neurocognitive Study (ARIC-NCS) without AF and who underwent a brain MRI and a 3DE examination in 2011-13. We defined 3 groups: those with no cerebral infarcts on brain MRI (NCIs, N = 315); those with MRI-diagnosed SCIs (N = 58); and those with clinically diagnosed stroke (N = 34).

Results

While still within the normal range, LA indexed volume significantly increased across the 3 groups (P-trend = 0.01).This was accompanied by an increase in the LA global longitudinal strain (GLS), an echocardiographic index of LA reservoir function (P-trend = 0.004). E/e’ divided by LA GLS—index of atrial stiffness—worsened across groups (P-trend = 0.005) and was independently associated with SCIs and Stroke, pooled together, [OR per 1 %-1, 1.97; 95% CI (1.24, 3.11), P = 0.004], and Stroke [OR per 1 %-1, 2.30; 95% CI (1.23, 4.30), P = 0.009]. LA GLS was marginally associated with an increased odd of SCIs [OR per 1 %, 1.07; 95% CI (1.01, 1.13), P = 0.014].

Conclusions

Among elderly participants with normal sinus rhythm and preserved ejection fraction in a large cohort study, markers of LA function and stiffness are associated with increased odds of subclinical infarcts and stroke. These data suggest that even subtle LA dysfunction, which may contribute to LA stasis, may predispose to subclinical cerebral infarcts and stroke.