Pertuzumab Plus Trastuzumab With or Without Chemotherapy Followed by Emtansine in ERBB2-Positive Metastatic Breast Cancer: A Secondary Analysis of a Randomized Clinical Trial

Importance

In ERBB2 (formerly HER2)-positive metastatic breast cancer (MBC), combining trastuzumab and pertuzumab with taxane-based chemotherapy is the first line of standard care. Given that trastuzumab plus pertuzumab was proven effective in ERBB2-positive MBC, even without chemotherapy, whether the optimal first-line strategy could be trastuzumab plus pertuzumab alone instead of with chemotherapy is unresolved.

Objective

To assess overall survival (OS) at 2 years and progression-free survival (PFS) for patients randomly assigned to receive first-line pertuzumab plus trastuzumab alone or with chemotherapy followed by trastuzumab and emtansine at progression; PFS of second-line trastuzumab and emtansine treatment following trastuzumab plus pertuzumab; and OS and PFS in the ERBB2-enriched and ERBB2-nonenriched subtypes.

Design, Setting, and Participants

This was a secondary analysis of a multicenter, open-label, phase 2 randomized clinical trial conducted at 27 sites in France, 20 sites in Switzerland, 9 sites in the Netherlands, and 1 site in Germany. Overall, 210 patients with centrally confirmed ERBB2-positive MBC were randomized between May 3, 2013, and January 4, 2016, with termination of the trial May 26, 2020. Data were analyzed from December 18, 2020, to May 10, 2022.

Interventions

Patients randomly received pertuzumab (840 mg intravenously [IV], then 420 mg IV every 3 weeks) plus trastuzumab (8 mg/kg IV, then 6 mg/kg IV every 3 weeks) without chemotherapy (group A) or pertuzumab plus trastuzumab (same doses) with either paclitaxel (90 mg/m2 for days 1, 8, and 15, then every 4 weeks for ≥4 months) or vinorelbine tartrate (25 mg/m2 for first administration followed by 30 mg/m2 on days 1 and 8 and every 3 weeks for ≥4 months) followed by pertuzumab plus trastuzumab maintenance after chemotherapy discontinuation (group B).

Main Outcomes and Measures

Overall survival at 24 months by treatment group, PFS for first-line treatment, PFS for second-line treatment, and patient-reported quality of life (QOL).

Results

A total of 210 patients were included in the analysis, with a median age of 58 (range, 26-85) years. For group A, 24-month OS was 79.0% (90% CI, 71.4%-85.4%); for group B, 78.1% (90% CI, 70.4%-84.5%). Median PFS with first-line treatment was 8.4 (95% CI, 7.9-12.0) months in group A and 23.3 (95% CI, 18.9-33.1) months in group B. Unlike expectations, OS and PFS did not markedly differ between populations with ERBB2-enriched and ERBB2-nonenriched cancer. Adverse events were less common without chemotherapy, with small QOL improvements from baseline in group A and stable QOL in group B.

Conclusions and Relevance

The findings of this secondary analysis of a randomized clinical trial suggest that the chemotherapy-free anti-ERBB2 strategy is feasible without being detrimental in terms of OS. The 50-gene prediction analysis of microarray signature could not help to identify the most appropriate patient population for this approach.

Trial Registration

ClinicalTrials.gov Identifier: NCT01835236.

Abstract P4-01-20: Phase IV study evaluating talazoparib in patients with locally advanced or metastatic negative HER2 breast cancer and a somatic or germline BRCA1/2 mutation (ViTAL) – Analysis of cohort 1 according to hormonal receptor status

Background: Talazoparib (TALA) is a highly potent, dual-mechanism PARP inhibitor that has demonstrated clinical benefit in EMBRACA Phase III trial for patients with germline BRCA1/2 mutated locally advanced or metastatic HER2- breast cancer.

Objective: The aim of the study is to ensure the effectiveness and safety of TALA in real-life setting among patients with locally advanced or metastatic HER2- breast cancer, with somatic or germline BRCA1/2 mutation.

Methods: ViTAL is an ambispective, multicentric, longitudinal, phase IV study. It includes two ambispective cohorts:

- Cohort 1: patients treated through the French Early Access Program and inclusion of patients with somatic BRCA1/2 mutation was allowed.

- Cohort 2: patients treated according to the European Marketing Approval granted in 09/21/2021.

Here we present the results of the primary and some secondary endpoints for cohort 1.

Results: From November 2018 to May 2021, 86 patients were included in Cohort 1, with updated results after a median follow-up of 17.3 months (11.2 - 24.4).

Patients’ characteristics are 53.5% of ER+ BC/46.5% of TNBC (refer to the table).

The median Time to Treatment Discontinuation (mTTD) was 9.0 months [range 6.0; 11.5] with 37.7% of patients still on treatment at 12 months. Subgroup analysis shows similar mTTD according HR status, germline vs somatic mutation and prior platinum exposure (refer to the table).

The Clinical Benefit Rate assessed by the investigators is 82.4% (Complete Response for 25.7%, Partial response R for 32.4% and stable disease for 24.3%).

The median of duration of CNS metastases control was 6.6 months, and 80.0% of patients had control of CNS metastases during TALA.

Out of the 85 treated patients, 69 patients (80,2%) experienced a TALA permanent discontinuation for progressive disease (84.1%), toxicity (10.1%), cancer-related death (1.4%), or other reasons (1.4%).

After discontinuation of TALA, 65.1% of patients received a subsequent treatment with a TTD of 2.3 months [1.7; 2.7]. The most common subsequent treatments were non-platinum chemotherapy (64.3%), platinum chemotherapy (19.6%) and others (19.1%).

At least one adverse events (AEs) was recorded in 74.4% of patients. Hematologic AEs (any grade) occurred in 48.8% (anemia 27.9%, thrombocytopenia 12.8%, neutropenia 10.5%).

Most common non-hematologic AEs were alopecia (8.1%) and asthenia (7.0%). Related Serious Hematologic AEs occurred in 10 patients (11.6%) including 7 (8.1%) Anemia.

Related Serious Non-hematologic AEs (vomiting, pyelonephritis and ascitis) were seen in 3 patients (3.6%). AEs associated with temporary drug interruption, dose modification and permanent drug discontinuation occurred in 36 (41.9%), 24 (27.9%), and 7 (10.1%) patients respectively.

The mOS is expected to be reached at the time of the congress, with 51.9% of patients still alive at 24 months.

Conclusions: ViTAL is the largest study that reports real-word data with TALA. Outcomes and safety in Cohort 1 are consistent with the results of EMBRACA study and give additional data on subgroups of interest (ie patients previously treated with carboplatin, presence of CNS).

(Litton et al. NEJM 2018)

mTTD on subgroups of interest

Patients’ characteristics

Citation Format: Delphine Loirat, Marie Duboys de la barre, Jean-Christophe Thery, Ioana Hrab, Christelle Jouannaud, Jean-Loup Mouysset, Laura Salabert, Pauline Soibinet, Audrey Mailliez, Romain Valery, Anne Creisson, Cristian Villanueva, Nadine Dohollou, Jean-david Fumet, Thomas grellety, Nathalie Perez-staub, Emma Lachaier, Aurore Iltis-roux, Miguel delbado, Abeer Najem, Romuald Le Scodan, Elsa Curtit, kais aldabbagh, Pascal Pujol, thibault DE LA MOTTE ROUGE. Phase IV study evaluating talazoparib in patients with locally advanced or metastatic negative HER2 breast cancer and a somatic or germline BRCA1/2 mutation (ViTAL) – Analysis of cohort 1 according to hormonal receptor status [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P4-01-20.

Abstract P4-01-04: Phase IV multicenter study evaluating RWE and the safety of talazoparib in patients with locally advanced or metastatic negative HER2 breast cancer and a BRCA1/2 mutation (ViTAL) - Cohort 2: patients treated according to the EMA

Background: Talazoparib (TALA) is a highly potent, dual-mechanism PARP inhibitor that has demonstrated clinical benefit in EMBRACA Phase III trial for patients with germline BRCA1/2 (BRCA1/2)-mutated locally advanced or metastatic HER2- breast cancer. Objective: The aim of the study is to ensure the effectiveness and safety of TALA in the real-world setting among patients with locally advanced or metastatic HER2- breast cancer, with somatic or germline BRCA1/2 mutation. Methods: ViTAL is an ambispective, multicentric, longitudinal, phase IV study. It includes two ambispective cohorts: - Cohort 1: patients treated through the French Early Access Program and inclusion of patients with somatic BRCA1/2 mutation was allowed. - Cohort 2: patients treated according to the European Marketing Approval granted in 09/21/2021. The primary endpoint of the study is the Time to Treatment Discontinuation (TTD) which is defined as time between the date of first dose of TALA and the date of last dose or death. Results: From November 2018 to May 2021, 85 patients were included in Cohort 2, Patients’ characteristics are: - a median age of 49.0 years; - 65.8% ER+ BC/34.2% TNBC; - 42.1% mBRCA1/55.3 % mBRCA2/2,6% mBRCA1 and mBRCA2. - 85.7% ECOG PS 0 or 1; - 23.4% de novo mBC. - Visceral, bones and CNS metastases were found in 59.0%, 61.5% and 10.3% of patients respectively. - No breast or ovarian cancer family history at 1st degree was found in 39 patients (50.0%). - 38.5% were chemo-naïve; - 21.8% received prior platinum in (neo)adjuvant or metastatic setting, with a median of prior cytotoxic regimen of 1 - For patients with ER+/HER2- ABC the median number of prior endocrine therapy was 1 and 62.0% of these patients received a CDK4/6 inhibitor prior to TALA. - 8 patients (10.3%) had CNS metastases. Out of the 78 treated patients, 57 patients (73.0%) experienced a TALA permanent discontinuation for Progressive disease (80.7%), toxicity (12.3%), cancer-related death (1.8%), or other reasons (1.8%). The median TTD for TALA is 9.6 months [6.7;10.8] with 34.5% of patients still on treatment at 12 months. After discontinuation of TALA, 59.0% of patients received a subsequent treatment with a TTD of 3.9 months [2.1; 45]. The most common subsequent treatments were non-platinum chemotherapy (67.4%), platinum therapy (6.5%) and other (26.1%). The Clinical Benefit Rate assessed by the investigators is 87.6% (Complete Response for 14.1%, Partial Response for 56.3% and Stable Disease for 17.2%). The median duration of CNS metastases control was 10.2 months, and 25.0% of patients had a control of CNS metastases. At least one adverse events (AEs) was recorded in 67.9% of patients. Hematologic adverse events (AEs) (any grade) occurred in 55.1% (anemia 37.2%, thrombocytopenia 16.7%, neutropenia 15.4%). Most common non-hematologic AEs were Nausea (15.4%) and asthenia (15.4%). Related Serious Hematologic AEs occurred in 6 patients (7.7%) including 3 (3.8%) thrombocytopenia and 3 (3.8%) anemia. Related Serious Non-hematologic AEs (metrorrhagia) were seen in 1 patient (1.3%). AEs associated with temporary drug interruption, dose modification and permanent drug discontinuation occurred in 26 (33.3%), 22 (28.2%), and 7 (12.3%) patients respectively. The mOS is not mature for this analysis. Conclusions: ViTAL is the largest study that reports real-word data with TALA. Outcomes and safety in Cohort 2 (patients treated with TALA according to the European Marketing Approval), are consistent with the results of EMBRACA study and with the Cohort 1. (Litton et al. NEJM 2018)

Citation Format: Delphine Loirat, Marie Duboys de la barre, Cristian Villanueva, Audrey Mailliez, Nicolas Isambert, Lionel Moreau, Emmanuelle Jacquet, Dominique Spaëth, Anne Creisson, Christelle Jouannaud, Eric Legouffe, Miguel delbado, Laura Deiana, Pauline Soibinet, Ioana Hrab, Thomas grellety, Nadine Dohollou, Raffaele Longo, Jean-Christophe Thery, Jean-david Fumet, Sellam Zineb, Pascal Pujol, thibault DE LA MOTTE ROUGE. Phase IV multicenter study evaluating RWE and the safety of talazoparib in patients with locally advanced or metastatic negative HER2 breast cancer and a BRCA1/2 mutation (ViTAL) - Cohort 2: patients treated according to the EMA [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P4-01-04.

Outcomes of patients with HER2-negative metastatic breast cancer after platinum- and non-platinum-based first-line chemotherapy among patients with and without pathogenic germline BRCA1/2 mutations

BACKGROUND

The efficacy and added benefit of platinum-based chemotherapy (PtCT) for metastatic breast cancer (MBC) remain unclear in patients with and without germline BRCA1 or BRCA2 mutations (gBRCA1/2m and gBRCA1/2wt, respectively).

METHODS

We selected from the French national real-world multicentre ESME cohort (2008-2016) all patients with HER2-negative MBC with known gBRCA1/2 status at first-line chemotherapy initiation. Using multivariable Cox models, we compared the outcome (progression-free (PFS) and overall survival (OS)) of first-line PtCT and non-PtCT regimens based on the patients' gBRCA1/2 status and tumour subtype.

RESULTS

Patients who received PtCT had more aggressive tumour features. In the multivariable analysis, first-line PtCT was associated with better adjusted PFS and OS in gBRCA1/2m carriers (N = 300), compared with non-PtCT (HR 0.54, 95% CI 0.4-0.73, P < 0.001, and HR 0.70, 95% CI 0.49-0.99, P = 0.047, respectively). Conversely, outcomes were similar in gBRCA1/2wt patients (N = 922) treated with PtCT and non-PtCT, whatever the tumour subtype. Landmark analyses at months 3 and 6 post treatment initiation supported these results.

CONCLUSIONS

In this pre-PARP inhibitor real-world cohort, PFS and OS were better after PtCT than non-PtCT in patients with gBRCA1/2m, but not in those with gBRCA1/2wt. These results emphasise the need of early gBRCA1/2 testing in patients with MBC.

CLINICAL TRIAL NUMBER

NCT03275311.

Genomics to select treatment for patients with metastatic breast cancer

Cancer progression is driven in part by genomic alterations¹. The genomic characterization of cancers has shown interpatient heterogeneity regarding driver alterations², leading to the concept that generation of genomic profiling in patients with cancer could allow the selection of effective therapies^3,4. Although DNA sequencing has been implemented in practice, it remains unclear how to use its results. A total of 1,462 patients with HER2-non-overexpressing metastatic breast cancer were enroled to receive genomic profiling in the SAFIR02-BREAST trial. Two hundred and thirty-eight of these patients were randomized in two trials (nos. NCT02299999 and NCT03386162) comparing the efficacy of maintenance treatment⁵ with a targeted therapy matched to genomic alteration. Targeted therapies matched to genomics improves progression-free survival when genomic alterations are classified as level I/II according to the ESMO Scale for Clinical Actionability of Molecular Targets (ESCAT)⁶ (adjusted hazards ratio (HR): 0.41, 90% confidence interval (CI): 0.27-0.61, P < 0.001), but not when alterations are unselected using ESCAT (adjusted HR: 0.77, 95% CI: 0.56-1.06, P = 0.109). No improvement in progression-free survival was observed in the targeted therapies arm (unadjusted HR: 1.15, 95% CI: 0.76-1.75) for patients presenting with ESCAT alteration beyond level I/II. Patients with germline BRCA1/2 mutations (n = 49) derived high benefit from olaparib (gBRCA1: HR = 0.36, 90% CI: 0.14-0.89; gBRCA2: HR = 0.37, 90% CI: 0.17-0.78). This trial provides evidence that the treatment decision led by genomics should be driven by a framework of target actionability in patients with metastatic breast cancer.

Abstract P1-18-28: Phase IV study evaluating effectiveness and safety of talazoparib in patients with locally advanced or metastatic HER2 negative breast cancer and a BRCA1 or BRCA2 mutation (ViTAL)

Background: Talazoparib (TALA) is a highly potent PARP inhibitor that has demonstrated clinical benefit in the phase III EMBRACA trial for patients with germline BRCA1 or BRCA2-mutation and a locally advanced or metastatic HER2 negative (HER2-) breast cancer (BC). Methods: ViTAL is an ambispective, multi-center longitudinal, phase IV study that aims to ensure the effectiveness and safety of TALA in the real-world setting among patients with locally advanced or metastatic HER2- BC, with somatic or germline BRCA mutation (sBRCA or gBRCA). This study includes two cohorts: - Cohort 1: patients treated through the French Early Access Program from November 2018 to September 2019. Inclusion of patients with sBRCA mutation was allowed. - Cohort 2: patients treated according to the European Marketing Approval granted 21/09/2021. The primary endpoint is Time to Treatment Discontinuation (TTD) for TALA defined as Time between the date of first dose of TALA and the date of last dose or death. Results: We present the results of Cohort 1 in which includes 85 patients. Patients’ characteristics are as follows: median age 50 years; 46% triple negative BC and 54% ER+ BC; 47% BRCA1-mutated and 53% BRCA2-mutated; 94% gBRCA and 6% sBRCA; 95% ECOG PS 0 or 1; 31% premenopausal status; 40% de novo metastatic BC (mBC). Visceral, bones and central nervous system metastases were found in 61%, 54% and 11% of patients, respectively. No breast or ovarian cancer in first degree relative was found in 35 patients (41%). The median number of prior cytotoxic regimen was 2, 15% were chemo-naïve for mBC; 35% received prior platinum in the neoadjuvant, adjuvant or metastatic setting. For patients with ER+/HER2- mBC the median number of prior endocrine therapy was 2 and 74% of these patients received a CDK4/6 inhibitor prior to TALA. The median follow-up was 17.4 months [range 15.7-20.5]. Of 85 treated patients, 66 patients (78%) experienced permanent discontinuation of TALA due to progressive disease (88%), toxicity (8%), cancer-related death (3%), or other reasons (1.5%). The median TTD for TALA was 9.0 months [range 6.0-11.0] with 35% of patients still in under treatment at 12 months. At least one adverse event (AEs) was recorded in 71% of patients. Hematologic AEs (any grade) occurred in 44% of patients (anemia for 26%, thrombocytopenia for 9%, neutropenia for 8%). The most common non-hematologic AEs were alopecia (6%) and asthenia (5%). Related serious hematologic AEs occurred in 7 (8%) patients including 6 (7%) with anemia. Related serious non-hematologic AEs (vomiting, pyelonephritis) were seen in 2 patients (2%). AEs associated with temporary drug interruption, dose modification and permanent drug discontinuation occurred in 32 (38%), 16 (19%), and 5 (8%) patients respectively. After discontinuation of TALA, 83% of patients received a subsequent treatment with a TTD of 2.4 months [range 1.7-3.3]. The most common subsequent treatments were non-platinum chemotherapy (64%) and platinum therapy (24%). Conclusions: The TTD of 9 months is consistent with the outcomes and safety results of the EMBRACA study. ViTAL, the first real-word study with TALA confirms its interest in locally advanced or metastatic HER2- BC. Analysis of Cohort 2 will occur when data are mature. (Ref Litton JK, Rugo HR, Ellt J et al. Talazoparib in Patients with Advanced Breast Cancer and a Germline BRCA Mutation. N Engl J Med. 2018; 379:753-763.

Citation Format: Delphine Loirat, Marie Duboys de Labarre, Christine Essner, Ioana Hrab, Jean-Christophe Thery, Christelle Jouannaud, Cristian Villanueva, Perrine Vuagnat, Pauline Soibinet-Oudot, Anne Creisson, Audrey Mailliez, Jean-Loup Mouysset, Laura Salabert, Nadine Dohollou, Jean-David Fumet, Thibault De La Motte Rouge, Jean-Michel Vauthier, Maylis Decrop, Pascal Pujol. Phase IV study evaluating effectiveness and safety of talazoparib in patients with locally advanced or metastatic HER2 negative breast cancer and a BRCA1 or BRCA2 mutation (ViTAL) [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P1-18-28.

Cost-effectiveness evaluation of pre-counseling telephone interviews before face-to-face genetic counseling in cancer genetics

One of the main challenges in cancer genetics is responding to the exponential demand for genetic counseling, especially in patients with breast and/or ovarian cancer. To address this demand, we have set up a new procedure, based on pre-genetic counseling telephone interviews (PTI) followed by routing of patients: D1, a PTI is scheduled within 14 days; D7-D14, genetic counselors perform a 20 min PTI in order to establish a pre-genetic counseling file, by collecting personal and family medical history via a structured questionnaire and; D10-17, routing: pre-genetic counseling appointment files are analyzed by a cancer geneticist with 3 possible conclusions: (a) priority face-to-face genetic counseling (FTFGC) appointment with a cancer geneticist, if the genetic test results have an immediate therapeutic impact; (b) non-priority FTFGC with a genetic counselor, or (c) no FTFGC required or substitution by a more appropriate index case. In the context of breast and/or ovarian cancer, 1012 patients received PTIs, 39.1% of which did not lead to FTFGC. The mean delay for non-priority FTFGC was maintained at 18 weeks and priority FTFGC appointments were guaranteed within 8 weeks. The required resources for 1012 patients was estimated at 0.12 FTE secretaries, 0.62 FTE genetic counselors and 0.08 FTE cancer geneticists and the procedure was shown to be cost-effective. This new procedure allows the suppression of up to 1/3 of appointments, guarantees priority for appointments with therapeutic impact and optimizes the interaction and breakdown of tasks between genetic counselors and cancer geneticists.

A European Organisation for Research and Treatment of Cancer randomized, double-blind, placebo-controlled, multicentre phase II trial of anastrozole in combination with gefitinib or placebo in hormone receptor-positive advanced breast cancer (NCT00066378)

BACKGROUND

Preclinical data suggest that epidermal growth factor receptor (EGFR) inhibitors (e.g. gefitinib) can delay endocrine resistance in breast cancer. A double-blind, placebo-controlled, phase II trial investigated whether adding gefitinib (G) to anastrozole (A) would improve outcome in advanced breast cancer (ABC).

METHODS

Postmenopausal pre-treated hormone receptor-positive ABC patients (locally recurrent or metastatic) were 1:1 randomized to A (1 mg/d) plus G 250 mg/d or plus placebo (P). Patients who had prior treatment with an aromatase inhibitor in metastatic setting or with trastuzumab, anti-EGFR or anti-VEGF agents were excluded. Treatment was given until disease progression, unacceptable toxicity or patient withdrawal. Progression-free survival (PFS) rate at 1 year was assessed according to Response Evaluation Criteria in Solid Tumours, version 1.0.

RESULTS

Of 108 planned patients, 71 were recruited (36 in A/G and 35 in A/P). The trial closed prematurely due to slow recruitment; 31 patients had prior chemotherapy and 53 prior endocrine therapy (all except one received tamoxifen); 60% in adjuvant and 16% in metastatic setting received tamoxifen; 59 patients had visceral disease. Median follow-up was 18 months. PFS rate at 1 year was 35% for A/G and 32% for A/P arm. Objective responses were six (22%) in the A/G and nine (28%) in the A/P arm. Median duration of response was 13.8 and 18.6 months in the A/G and A/P arms, respectively. Fatigue (35%), diarrhoea (31%), rash (32%), dry skin (27%), and arthralgia/myalgia (27%) were the commonest adverse events in the A/G arm.

CONCLUSIONS

This phase II study, although prematurely closed, did not show a signal that adding G to A improves PFS at 1 year and its use is not supported. Gastrointestinal and skin toxicities were more pronounced with G resulting in premature therapy interruption in almost 1 in 3 patients (ClinicalTrials.gov number, NCT00066378).

[Renovascular safety of bevacizumab in breast cancer patients. The prognostic value of hypertension and proteinuria]

INTRODUCTION

The potential prognostic value of hypertension and proteinuria of anti-vascular endothelial growth factor (VEGF) drugs has not been assessed in routine clinical practice so far in breast cancer. The objectives of the MARS study were to assess the prevalence of proteinuria and hypertension at baseline, their incidence under anti-VEGF treatment, and to evaluate a possible link with overall survival.

METHODS

Patients from 8 centres were included between 2009 and 2011 with a follow-up of 1 year. They were naive of any previous anti-VEGF treatment and planned to be started on one. The results of the group of patients with breast cancer receiving bevacizumab are presented.

RESULTS

Four hundred and two patients with breast cancer and treated with bevacizumab were included. At inclusion, hypertension prevalence was 12.4%, proteinuria 23.9%. The incidence of de novo proteinuria and hypertension during the follow-up was 61.7% and 16.8%, respectively. Among patients with de novo proteinuria, 62.2% afterwards improved/normalized. No thrombotic microangiopathy was reported. Baseline or de novo proteinuria/hypertension were not associated with overall survival in breast cancer patients treated with bevacizumab.

DISCUSSION

These results on the renovascular safety of bevacizumab in breast cancer patients showed that the prevalence of hypertension and proteinuria was high at baseline and, moreover, patients treated with bevacizumab frequently developed de novo hypertension and/or proteinuria. Finally, neither hypertension, nor proteinuria, neither at baseline, nor de novo, were associated with overall survival in our cohort of "real-life'' patients

Reliability of Prognostic and Predictive Factors Evaluated by Needle Core Biopsies of Large Breast Invasive Tumors

OBJECTIVES

Preoperative biopsy of breast cancer allows for prognostic/predictive marker assessment. However, large tumors, which are the main candidates for preoperative chemotherapy, are potentially more heterogeneous than smaller ones, which questions the reliability of histologic analyses of needle core biopsy (NCB) specimens compared with whole surgical specimens (WSS). We studied the histologic concordance between NCB specimens and WSS in tumors larger than 2 cm.

METHODS

Early pT2 or higher breast cancers diagnosed between 2008 and 2011 in our center, with no preoperative treatments, were retrospectively screened. We assessed the main prognostic and predictive validated parameters. Comparisons were performed using the κ test.

RESULTS

In total, 163 matched NCB specimens and WSS were analyzed. The correlation was excellent for ER and HER2 (κ = 0.94 and 0.91, respectively), moderate for PR (κ = 0.79) and histologic type (κ = 0.74), weak for Ki-67 (κ = 0.55), and minimal for SBR grade (κ = 0.29). Three of the 21 HER2-positive cases (14% of HER2-positive patients or 1.8% of all patients), by WSS analysis, were initially negative on NCB specimens even after chromogenic in situ hybridization.

CONCLUSIONS

NCB for large breast tumors allowed reliable determination of ER/PR expression. However, the SBR grade may be deeply underestimated, and false-negative evaluation of the HER2 status would have led to a detrimental lack of trastuzumab administration.

Short report: Monitoring ESR1 mutations by circulating tumor DNA in aromatase inhibitor resistant metastatic breast cancer

Acquired estrogen receptor gene (ESR1) mutations have been recently reported as a marker of resistance to aromatase inhibitors in hormone receptor positive metastatic breast cancer. We retrospectively considered seven patients treated for metastatic breast cancer with available samples from the primary tumor before any treatment, cryopreserved metastasis removed during progression and concomitant plasmas. All these seven patients were in disease progression after previous exposure to aromatase inhibitors for at least 6 months, and were assessed for ESR1 mutations detection in tumor and circulating DNA. For these patients, Sanger sequencing identified four metastases with clear ESR1 mutation and one possible, whereas digital PCR identified six mutated metastases. Then, under blind conditions and using digital PCR, corresponding circulating ESR1 mutations were successfully detected in four of these six metastatic breast cancer patients. Moreover, in two patients with serial blood samples following treatments exposure, the monitoring of circulating ESR1 mutations clearly predicted disease evolution. In the context of high interest for ESR1 mutations, our results highlight that these acquired recurrent mutations may be tracked in circulating tumor DNA and may be of clinical relevance for metastatic breast cancer patient monitoring.

Abstract 5138: Expression and circulating levels of VEGFC/VEGFD and their receptor VEGFR2, R3 in renal cell cancer: Relationship with clinicopathological parameters

Background: Vascular endothelial growth factors C, VEGF-D and VEGFR-2, R-3, are overexpressed in different malignancies and associated with lymph node metastasis and poor prognosis. In renal cell cancer (RCC) lymphatic tumor spread exists but data focusing on lymphangiogenesis are rare. Since the VEGF-C/VEGF-D/VEGFR-2, R-3 axis appears to be the signaling pathway for tumor-induced lymphangiogenesis and an attractive target for therapeutic intervention; we analyzed the expression and the presence of the soluble forms in 30 non treated metastatic RCC patients and results were correlated with clinicopathological parameters. Methods: Tumor and sera from 30 metastatic renal cell cancer patients (20 clear cell (ccRCC)&10 papillary (pRCC) were included in this study. The expressions of VEGFR-2,R-3 &VEGF-C,-D expressions on tumor were evaluated by immunohistochemestry. Using ELISA assays, soluble vegfr-2–3 &sVEGF-C,-D were measured in sera of RCC patients in comparison to 20 healthy controls. Results: In overall patients, a high expression of VEGF-C,-D and their receptors were observed in more than 55% of the patients as compared to the negative control. Regarding circulating VEGF-C,-D, R2, R-3 they were variable in all samples from either patients or healthy donors. Only median sVEGF- R3 level was significantly higher (p=0.005) in RCC patients as compared to healthy donors. VEGF-C and VEGF-D expression was significantly correlated (r’=0.43, p=0.02) with each other but not with the expression of its receptors. An inverse correlation between Flt-4 expression & its soluble form was noted (r=−0.33 p=0.040). The expression of VEGF-C, VECF-D and sVEGFR-3 were significantly higher in pRCC than ccRCC (p=0.02, 0.01 and 0.035 respectively). The expression of VEGFR-2, VEGFR-3 were not different between the subgroups (p=0.11). Furthermore, no correlation with clinicopathological parameters was shown in either overall patients or in the two subgroups. Conclusions: we showed that in RCC the lymphangiogenic factors are expressed or present as soluble form, a different expression pattern in ccRCC and pRCC existe. Therefore, further studies are necessary to determine if lymphangiogenesis can play a role as a prognostic tool or a target for therapeutic intervention in renal cell carcinoma.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 5138. doi:10.1158/1538-7445.AM2011-5138