Giredestrant for Estrogen Receptor-Positive, HER2-Negative, Previously Treated Advanced Breast Cancer: Results From the Randomized, Phase II acelERA Breast Cancer Study

PURPOSE

To compare giredestrant and physician's choice of endocrine monotherapy (PCET) for estrogen receptor-positive, HER2-negative, advanced breast cancer (BC) in the phase II acelERA BC study (ClinicalTrials.gov identifier: NCT04576455).

METHODS

Post-/pre-/perimenopausal women, or men, age 18 years or older with measurable disease/evaluable bone lesions, whose disease progressed after 1-2 lines of systemic therapy (≤1 targeted, ≤1 chemotherapy regimen, prior fulvestrant allowed) were randomly assigned 1:1 to giredestrant (30 mg oral once daily) or fulvestrant/aromatase inhibitor per local guidelines (+luteinizing hormone-releasing hormone agonist in pre-/perimenopausal women, and men) until disease progression/unacceptable toxicity. Stratification was by visceral versus nonvisceral disease, prior cyclin-dependent kinase 4/6 inhibitor, and prior fulvestrant. The primary end point was investigator-assessed progression-free survival (INV-PFS).

RESULTS

At clinical cutoff (February 18, 2022; median follow-up: 7.9 months; N = 303), the INV-PFS hazard ratio (HR) was 0.81 (95% CI, 0.60 to 1.10; P = .1757). In the prespecified secondary end point analysis of INV-PFS by ESR1 mutation (m) status in circulating tumor DNA-evaluable patients (n = 232), the HR in patients with a detectable ESR1m (n = 90) was 0.60 (95% CI, 0.35 to 1.03) versus 0.88 (95% CI, 0.54 to 1.42) in patients with no ESR1m detected (n = 142). Related grade 3-4 adverse events (AEs), serious AEs, and discontinuations due to AEs were balanced across arms.

CONCLUSION

Although the acelERA BC study did not reach statistical significance for its primary INV-PFS end point, there was a consistent treatment effect with giredestrant across most key subgroups and a trend toward favorable benefit among patients with ESR1-mutated tumors. Giredestrant was well tolerated, with a safety profile comparable to PCET and consistent with known endocrine therapy risks. Overall, these data support the continued investigation of giredestrant in other studies.

Late onset toxicities associated with the use of CDK 4/6 inhibitors in hormone receptor positive (HR+), human epidermal growth factor receptor-2 negative (HER2-) metastatic breast cancer patients: a multidisciplinary, pan-EU position paper regarding their optimal management. The GIOCONDA project

The personalization of therapies in breast cancer has favoured the introduction of new molecular-targeted therapies into clinical practice. Among them, cyclin-dependent kinases 4 and 6 (CDK4/6) inhibitors have acquired increasing importance, with the approval in recent years of palbociclib, ribociclib, and abemaciclib in combination with endocrine therapy. Currently, no guidelines are available to monitor and manage potential long-term toxicities associated with the use of these drugs. A multidisciplinary panel of European oncologists, was supported by a pharmacologist, a hematologist, a hepatologist and a pulmonologist to discuss the management of long-term toxicities, based on the literature review and their clinical experience. The panel provided detailed roadmaps to manage long-term toxicities associated with the use of CDK4/6 inhibitors in clinical practice. Knowing the frequency and characteristics of the toxicity profile associated with each CDK4/6 inhibitor is important in the decision-making process to match the right drug to the right patient.

Caveolin Gene Expression Predicts Clinical Outcomes for Early-Stage HER2-Negative Breast Cancer Treated with Paclitaxel-Based Chemotherapy in the GeparSepto Trial

PURPOSE

Caveolin-1 and -2 (CAV1/2) dysregulation are implicated in driving cancer progression and may predict response to nab-paclitaxel. We explored the prognostic and predictive potential of CAV1/2 expression for patients with early-stage HER2-negative breast cancer receiving neoadjuvant paclitaxel-based chemotherapy regimens, followed by epirubicin and cyclophosphamide.

EXPERIMENTAL DESIGN

We correlated tumor CAV1/2 RNA expression with pathologic complete response (pCR), disease-free survival (DFS), and overall survival (OS) in the GeparSepto trial, which randomized patients to neoadjuvant paclitaxel- versus nab-paclitaxel-based chemotherapy.

RESULTS

RNA sequencing data were available for 279 patients, of which 74 (26.5%) were hormone receptor (HR)-negative, thus triple-negative breast cancer (TNBC). Patients treated with nab-paclitaxel with high CAV1/2 had higher probability of obtaining a pCR [CAV1 OR, 4.92; 95% confidence interval (CI), 1.70-14.22; P = 0.003; CAV2 OR, 5.39; 95% CI, 1.76-16.47; P = 0.003] as compared with patients with high CAV1/2 treated with solvent-based paclitaxel (CAV1 OR, 0.33; 95% CI, 0.11-0.95; P = 0.040; CAV2 OR, 0.37; 95% CI, 0.12-1.13; P = 0.082). High CAV1 expression was significantly associated with worse DFS and OS in paclitaxel-treated patients (DFS HR, 2.29; 95% CI, 1.08-4.87; P = 0.030; OS HR, 4.97; 95% CI, 1.73-14.31; P = 0.003). High CAV2 was associated with worse DFS and OS in all patients (DFS HR, 2.12; 95% CI, 1.23-3.63; P = 0.006; OS HR, 2.51; 95% CI, 1.22-5.17; P = 0.013), in paclitaxel-treated patients (DFS HR, 2.47; 95% CI, 1.12-5.43; P = 0.025; OS HR, 4.24; 95% CI, 1.48-12.09; P = 0.007) and in patients with TNBC (DFS HR, 4.68; 95% CI, 1.48-14.85; P = 0.009; OS HR, 10.43; 95% CI, 1.22-89.28; P = 0.032).

CONCLUSIONS

Our findings indicate high CAV1/2 expression is associated with worse DFS and OS in paclitaxel-treated patients. Conversely, in nab-paclitaxel-treated patients, high CAV1/2 expression is associated with increased pCR and no significant detriment to DFS or OS compared with low CAV1/2 expression.

Efficacy of Endocrine Therapy Plus Trastuzumab and Pertuzumab vs De-escalated Chemotherapy in Patients with Hormone Receptor-Positive/ERBB2-Positive Early Breast Cancer: The Neoadjuvant WSG-TP-II Randomized Clinical Trial

Importance

Combination of chemotherapy with (dual) ERBB2 blockade is considered standard in hormone receptor (HR)-positive/ERBB2-positive early breast cancer (EBC). Despite some promising data on endocrine therapy (ET) combination with dual ERBB2 blockade in HR-positive/ERBB2-positive BC, to our knowledge, no prospective comparison of neoadjuvant chemotherapy vs ET plus ERBB2 blockade in particular with focus on molecular markers has yet been performed.

Objective

To determine whether neoadjuvant de-escalated chemotherapy is superior to endocrine therapy, both in combination with pertuzumab and trastuzumab, in a highly heterogeneous HR-positive/ERBB2-positive EBC.

Design, Setting, and Participants

This prospective, multicenter, neoadjuvant randomized clinical trial allocated 207 patients with centrally confirmed estrogen receptor-positive and/or progesterone receptor-positive (>1%) HR-positive/ERBB2-positive EBC to 12 weeks of standard ET (n = 100) vs paclitaxel (n = 107) plus trastuzumab and pertuzumab. A total of 186 patients were required to detect a statistically significant difference in pathological complete response (pCR) (assumptions: 19% absolute difference in pCR; power, ≥80%; 1-sided Fisher exact test, 2.5% significance level).

Interventions

Standard ET (aromatase inhibitor or tamoxifen) or paclitaxel, 80 mg/m2, weekly plus trastuzumab and pertuzumab every 21 days.

Main Outcomes and Measures

The primary end point was pCR (ypT0/is, ypN0). Secondary end points included safety, translational research, and health-related quality of life. Omission of further chemotherapy was allowed in patients with pCR. PAM50 analysis was performed on baseline tumor biopsies.

Results

Of the 207 patients included (median [range] age, 53 [25-83] years), 121 (58%) had cT2 to cT4 tumors, and 58 (28%) had clinically node-positive EBC. The pCR rate in the ET plus trastuzumab and pertuzumab arm was 23.7% (95% CI, 15.7%-33.4%) vs 56.4% (95% CI, 46.2%-66.3%) in the paclitaxel plus trastuzumab and pertuzumab arm (odds ratio, 0.24; 95% CI, 0.12-0.46; P < .001). Both immunohistochemical ERBB2 score of 3 or higher and ERBB2-enriched subtype were independent predictors for pCR in both arms. Paclitaxel was superior to ET only in the first through third quartiles but not in the highest ERBB2 quartile by messenger RNA. In contrast with the paclitaxel plus trastuzumab and pertuzumab arm, no decrease in health-related quality of life after 12 weeks was observed in the ET plus trastuzumab and pertuzumab arm.

Conclusions and Relevance

The WSG-TP-II randomized clinical trial is, to our knowledge, the first prospective trial comparing 2 neoadjuvant de-escalation treatments in HR-positive/ERBB2-positive EBC and demonstrated an excellent pCR rate after 12 weeks of paclitaxel plus trastuzumab and pertuzumab that was clearly superior to the pCR rate after ET plus trastuzumab and pertuzumab.

Trial Registration

ClinicalTrials.gov Identifier: NCT03272477.

PRECYCLE: multicenter, randomized phase IV intergroup trial to evaluate the impact of eHealth-based patient-reported outcome (PRO) assessment on quality of life in patients with hormone receptor positive, HER2 negative locally advanced or metastatic breast cancer treated with palbociclib and an aromatase inhibitor or palbociclib and fulvestrant

BACKGROUND

Efficacy and quality of life (QoL) are key criteria for therapy selection in metastatic breast cancer (MBC). In hormone receptor positive (HR +) human epidermal growth factor receptor 2 negative (HER2 -) MBC, addition of targeted oral agents such as everolimus or a cycline-dependent kinase 4/6 (CDK 4/6) inhibitor (e.g., palbociclib, ribociclib, abemaciclib) to endocrine therapy substantially prolongs progression-free survival and in the case of a CDK 4/6i also overall survival. However, the prerequisite is adherence to therapy over the entire course of treatment. However, particularly with new oral drugs, adherence presents a challenge to disease management. In this context, factors influencing adherence include maintaining patients' satisfaction and early detection/management of side effects. New strategies for continuous support of oncological patients are needed. An eHealth-based platform can help to support therapy management and physician-patient interaction.

METHODS

PreCycle is a multicenter, randomized, phase IV trial in HR + HER2 - MBC. All patients (n = 960) receive the CDK 4/6 inhibitor palbociclib either in first (62.5%) or later line (37.5%) together with endocrine therapy (AI, fulvestrant) according to national guidelines. PreCycle evaluates and compares the time to deterioration (TTD) of QoL in patients supported by eHealth systems with substantially different functionality: CANKADO active vs. inform. CANKADO active is the fully functional CANKADO-based eHealth treatment support system. CANKADO inform is a CANKADO-based eHealth service with a personal login, documentation of daily drug intake, but no further functions. To evaluate QoL, the FACT-B questionnaire is completed at every visit. As little is known about relationships between behavior (e.g., adherence), genetic background, and drug efficacy, the trial includes both patient-reported outcome and biomarker screening for discovery of forecast models for adherence, symptoms, QoL, progression free survival (PFS), and overall survival (OS).

DISCUSSION

The primary objective of PreCycle is to test the hypothesis of superiority for time to deterioration (TTD) in terms of DQoL = "Deterioration of quality of life" (FACT-G scale) in patients supported by an eHealth therapy management system (CANKADO active) versus in patients merely receiving eHealth-based information (CANKADO inform). EudraCT Number: 2016-004191-22.

Inferred immune-cell activity is an independent predictor of HER2 negative breast cancer prognosis and response to paclitaxel-based therapy in the GeparSepto trial

PURPOSE

Tumor microenvironment (TME) immune markers have been correlated with both response to neoadjuvant therapy and prognosis in breast cancer (BC) patients. Here, immune-cell activity of BC tumors was inferred by expression-based analysis to determine if it is prognostic and/or predictive of response to neoadjuvant paclitaxel-based therapy in the GeparSepto (G7) trial (NCT01583426).

EXPERIMENTAL DESIGN

Pre-study biopsies from 279 HER2 negative BC patients in the G7 trial underwent RNAseq-based profiling of 104 immune-cell specfic genes to assess inferred Immune Cell Activity (iICA) of 23 immune-cell types. Hierarchical clustering was used to classify tumors as iICA 'hot', 'warm' or 'cold' by comparison of iICA in the G7 cohort relative to that of 1467 samples from a tumor database established by Nantomics LLC. Correlations between iICA cluster, pathology-assessed TILs, and hormone receptor (HR) status for pathologic complete response (pCR), disease-free survival (DFS) and overall survival (OS), were determined.

RESULTS

iICA cluster correlated with TIL levels. The highest pCR rates were observed in hot cluster tumors, and those with relatively higher TILs. Greater inferred activity of several T-cell types was significantly associated with pCR and survival. DFS and OS were prolonged in patients with hot or warm cluster tumors, the latter particularly for HR negative tumors, even if TILs were relatively low.

CONCLUSIONS

Overall, TIL level better predicted pCR, but iICA cluster better predicted survival. Differences in associations between TILs, cluster, pCR and survival were observed for HR positive versus negative tumors, suggesting expanded study of the implication of these findings is warranted.

Abstract PD11-03: PD11-03 Comparison of a mono Atezolizumab window followed by Atezolizumab and chemotherapy with Atezolizumab and chemotherapy in triple negative breast cancer – an interim analysis of the adaptive randomized neoadjuvant trial NeoMono

Introduction: Improvement of systemic treatment of TNBC represents an unmet medical need. Targeted therapy of regulatory immune pathways has become an important option in the treatment of many malignant diseases including breast cancer. Neodjuvant trials combining chemotherapy and checkpoint inhibitors (KEYNOTE-522 and IMpassion031) have demonstrated a meaningful benefit regarding pathological complete remission (pCR) for the addition of PD-1- or PD-L1-inhibitors to chemotherapy in patients with TNBC. In the KEYNOTE-522 trial, the addition of an immune checkpoint inhibitor (ICI) to neoadjuvant chemotherapy also had a beneficial impact on event-free survival even in patients who did not achieve a pCR. Of note, in the neoadjuvant GeparNuevo trial only those patients with TNBC who received a 2-week checkpoint inhibitor monotherapy window before the start of neoadjuvant chemotherapy in combination with checkpoint inhibition, achieved a significant pCR benefit from the addition of the PD-1 inhibitor Durvalumab to neoadjuvant chemotherapy alone. Methods: NeoMono is a phase 2 randomized multicenter trial recruiting male and female patients with primary TNBC (defined as ER/PR &lt; 10% and HER2 negative). Neoadjuvant treatment in Arm A and B consists of Atezolizumab 1200 mg every 3 weeks in addition to neoadjuvant chemotherapy (i.e., 12 x Carboplatin and Paclitaxel q1w followed by Epirubicin and Cyclophosphamide q3w). Combination therapy in arm A is preceded by an Atezolizumab monotherapy window (i.e., 840 mg Atezolizumab once two weeks prior to initiation of combination therapy). Study goals are to compare the efficacy of neoadjuvant chemotherapy with Atezolizumab with and without an Atezolizumab two-week monotherapy window (primary endpoint: pCR) and the identification of biomarkers predicting (early) response to or resistance against Atezolizumab. The extensive translational program of the neoMono trial aims at identifying these biomarkers on tumor and patient level through analysis of sequential tissue and liquid biopsies. The NeoMono statistical design adapts the idea of a proof-of-concept trial and uses Bayesian posterior and predictive probabilities for inference about the primary hypothesis. Up to four planned efficacy interim analyses provide decision points for early stopping for success or futility. The expected maximum number of patients to be recruited is 458. Results: The predefined number of 50 patients in each arm being evaluable for the primary endpoint pCR has been reached and the results of the first planned interim analysis will be presented at the meeting. Conclusion: The addition of an ICI to state of the art neoadjuvant chemotherapy has recently been established as a new standard of care in TNBC. NeoMono has the potential to answer the question if the beneficial effect of the ICI can be increased by a chemotherapy free ICI monotherapy window prior to a combination with neoadjuvant chemotherapy.

Citation Format: Hans-Christian Kolberg, Johannes Schumacher, Ramona Erber, Michael Braun, Bernhard Heinrich, Oliver Hoffmann, Peter A. Fasching, Georg Kunz, Michael P. Lux, Christian Schem, Eva-Maria Grischke, Mustafa Deryal, Kristina Lübbe, Arndt Hartmann, Sabine Kasimir-Bauer, Cornelia Kolberg-Liedtke. PD11-03 Comparison of a mono Atezolizumab window followed by Atezolizumab and chemotherapy with Atezolizumab and chemotherapy in triple negative breast cancer – an interim analysis of the adaptive randomized neoadjuvant trial NeoMono [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 PD11-03.

Abstract HER2-06: HER2-06 Outcome analysis of HER2-zero or HER2-low hormone receptor-positive (HR+) breast cancer patients - characterization of the molecular phenotype in combination with molecular subtyping

Background: Breast cancer with low HER2 expression (HER2-low) is of high clinical relevance because of new therapeutic options with antibody-drug conjugates. We have recently shown in a large cohort from neoadjuvant clinical trials that HER2-low breast cancer has different molecular characteristics as well as different clinical outcomes compared to HER2-zero. Considering the positive correlation between HER2-low expression and hormone receptor positivity observed consistently in many investigations, we have extended our analysis to HR+ tumors from the post-neoadjuvant PenelopeB trial. In PenelopeB, patients with HR+ breast cancer and residual disease after neoadjuvant chemotherapy (NACT) were randomized to post-neoadjuvant palbociclib versus placebo in addition to endocrine therapy. We evaluated the molecular phenotype and clinical outcomes of HER2-low compared to HER2-zero patients. Methods: A total of 1250 patients were randomized, HER2 status was available for 1151 tumors from pretherapeutic core biopsy, determined mainly by local pathology, and from 1213 tumors from the post-NACT sample, determined as part of central pathology. For 1119 patients a paired HER2-status was both available. HER2-zero was defined as IHC0 and HER2-low-positive was defined as IHC1+ or IHC2+/ISH-. Gene expression analysis of 2549 genes using the HTG oncology biomarker panel was performed in 620 pretherapeutic biopsies and 780 post-NACT residual tumor samples, with 539 paired gene expression samples. Breast cancer subtypes were determined using the AIMS approach. Results: In pretherapeutic biopsies, 695 tumors (60%) were HER2-low and 457 (40%) were HER2-zero. A HER2-low status in the biopsy was significantly linked to improved iDFS (HR 0.76 (0.60-0.96; p=0.02). In residual tumors, 632 tumors (60%) were HER2-low and 581 (40%) were HER2-zero, without any prognostic impact of HER2 low status. In addition, a shift of HER2-low-status comparing core biopsy and residual tumor was observed in 415 (37%) of 1119 tumors. 161 (14%) had a shift from HER2-zero to HER2-low and 254 (23%) shifted from HER2-low to HER2-zero. A shift from HER2-zero to HER2-low in the post-NACT samples was significantly linked to reduced iDFS (HR 1.43 [95%CI 1.01-2.01]), p=0.04), compared to HER2-low group, while a shift from HER2-low to HER2-zero was associated with better iDFS compared to HER2-zero group, although not statistically significant (p=0.17). We did not observe a significant correlation of HER2-low status and AIMS molecular subtypes. In particular, the HER2-enriched (HER2E) subtype was assigned to only 4.3% of HER2-zero and 3.1% of HER2-low tumors. Significant iDFS differences were observed for HER2-low-status in combination with AIMS subtypes (lumB/basal/HER2E vs. lumA/normL; overall p-value &lt; 0.0001) for both pretherapeutic biopsies and residual tumor. Patients with post-NACT HER2-low tumors had an improved survival in the subgroups of aggressive AIMS subtypes (lumB/basal/HER2E), but not in the less aggressive AIMs subtypes (lumA/normL), with a positive test for interaction (p=0.02). For the pre-NACT samples a similar, but non-significant trend was observed. We evaluated a total of 620 core biopsies for differences in gene expression comparing HER2-low and HER2-zero tumors. A total of 417 genes were statistically significantly different, but in a hierarchical clustering there was no clear separation of HER2-low and HER2-zero tumors. Conclusions: In the PenelopeB cohort of HR+ tumors, a HER2-low status in pretherapeutic core biopsies is related to improved disease-free survival, especially for those tumors that have a more aggressive intrinsic subtype. A shift of HER2-low status was observed before and after chemotherapy, indicating an adaptation of the pathway activity to therapy-induced stress, which might become relevant for future diagnostic and therapeutic approaches.

Citation Format: Carsten Denkert, Miguel Martín, Michael Untch, Hervé R. Bonnefoi, Erik S. Knudsen, Seock-Ah Im, Angela DeMichele, Agnieszka Witkiewicz, Laura Van ’t Veer, Sung-Bae Kim, Harry D. Bear, Nicole McCarthy, Karen Gelmon, Frederik Marmé, José Ángel García-Sáenz, Nicholas Turner, Federico Rojo, Martin Filipits, Lesley-Ann Martin, Peter A. Fasching, Christian Schem, Catherine M. Kelly, Toralf Reimer, Masakazu Toi, Hope Rugo, Michael Gnant, Andreas Makris, Yuan Liu, Karsten Weber, Sivaramakrishna Rachakonda, Sibylle Loibl. HER2-06 Outcome analysis of HER2-zero or HER2-low hormone receptor-positive (HR+) breast cancer patients - characterization of the molecular phenotype in combination with molecular subtyping [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 HER2-06.

Abstract PD17-06: Immunohistochemical markers and determinants of clinical response in the Penelope-B trial

Background: The Penelope-B trial did not show improvement in invasive disease-free survival (iDFS) with the addition of palbociclib to endocrine therapy (ET) in patients with high-risk early breast cancer (BC) after neoadjuvant chemotherapy (NACT). Biomarkers may be able to identify subgroups of patients deriving benefit from Palbociclib and guide future studies. Estrogen-receptor (ER), progesterone-receptor (PgR) and Ki-67 might be helpful in identifying patients benefiting from palbociclib. Concordantly, tumors with elevated expression of Cyclin D1 and phosphorylated retinoblastoma protein (phospho-RB) may harbor more dependency on CDK4/6 and thus higher sensitivity to palbociclib. Methods: The percentage of positive ER and PgR cells and Ki-67 assessed in surgical specimens after NACT were combined to obtain the immunohistochemical score 3 (IHC3, Cuzick et al JCO 2011, low vs high based on the median IHC3 value). Cyclin D1 and phospho-RB Ser 807/811 immunoreactive (phospho-RB) scores were analyzed in residual tumors after NACT (range 0-12 each). Proportional hazard regression model was used to assess the predictive and prognostic value of IHC3 and treatment on iDFS. Subgroup analysis was performed according to BC intrinsic subtypes (luminal-A/normal-like, luminal-B/HER2-enriched/basal) and HER2-status (HER2 0, HER2 low). Cox/Fine-Gray regression was used to define the predictive and prognostic value of CyclinD1 (≤1, &gt;1), phospho-RB (≤2, &gt;2) as dichotomized and continuous variables on iDFS, distant DFS (DDFS), locoregional invasive recurrence-free interval (LRRFI) and overall survival (OS). Multivariate analyses (MVA) were adjusted for age (≤50 vs &gt;50), Ki-67 (≤15 vs &gt;15), region (non-Asian vs Asian), ypN (ypN0-1 vs ypN2-3), risk status (CPS-EG=2 ypN+ vs ≥3), cT (cT1-2 vs cT3-4), ypT (ypT0-2 vs ypT3-4), and grade (G1-2 vs G3). The MVA for IHC3 includes all the covariates above except Ki-67. p&lt; 0.05 was defined as statistically significant. Results: Data for ER, PgR, Ki-67, HER2, Cyclin D1 and phospho-RB were available for 1250 patients. Overall, 98.9% of the patients had ER+ tumors, 75.0% PgR+, 52.2% had HER2 low, 25.5% Ki-67&gt;15, 50% had IHC3 score higher than median, 93.9% had Cyclin D1 &gt;1, 57.8% had phospho-RB &gt;2. Patients with IHC3 score high had a worse iDFS compared to patients with IHC3 score low (MVA HR 2.28 95%CI (1.78-2.91), p&lt; 0.0001). Patients with luminal-A/normal-like tumors and IHC3 low had an improved iDFS with the addition of palbociclib to ET (MVA HR 0.35 95%CI (0.14-0.90), test for interaction p=0.01). No difference was observed according to HER2 status. Cyclin D1&gt;1 has no predictive value but is prognostic for better iDFS (MVA HR 0.62 95%CI (0.41-0.94), p=0.023), LRRFI (MVA HR 0.30 95%CI (0.15-0.63), p=0.001) and OS (MVA HR 0.50 95%CI (0.28-0.89), p=0.019). Similar results were obtained when Cyclin D1 was analysed as a continuous variable. Phospho-RB had neither predictive nor prognostic value. Phospho-RB highly correlates with Ki-67 (p&lt; 0.001, Spearman correlation 0.248). Conclusions: Patients with high Cyclin D1 expression had a favorable prognosis independent of treatment arm, but patients with luminal-A/normal-like tumors and IHC3 low after NACT had an improved outcome when receiving palbociclib in addition to adjuvant ET. Theses exploratory studies suggest specific signatures/phenotypes could predict benefit from Palbociclib in high-risk early breast cancer.

Citation Format: Erik S. Knudsen, Sivaramakrishna Rachakonda, Frederik Marmé, Miguel Martín, Michael Untch, Hervé R. Bonnefoi, Wolfgang D. Schmitt, Sung-Bae Kim, Harry D. Bear, Agnieszka Witkiewicz, Seock-Ah Im, Angela DeMichele, Laura Van’t Veer, Nicole McCarthy, Bruno V. Sinn, Karen Gelmon, José Ángel García-Sáenz, Catherine M. Kelly, Toralf Reimer, Nicholas Turner, Federico Rojo, Martin Filipits, Peter A. Fasching, Christian Schem, Lesley-Ann Martin, Yuan Liu, Masakazu Toi, Hope Rugo, Michael Gnant, Andreas Makris, Jenny Furlanetto, Karsten Weber, Carsten Denkert, Sibylle Loibl. Immunohistochemical markers and determinants of clinical response in the Penelope-B trial [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 PD17-06.

Abstract PD9-04: Immunological and clinical consequences of durvalumab treatment in combination to neoadjuvant chemotherapy in triple-negative breast cancer patients

Background: The implementation of immune checkpoint inhibitors in the therapy of different cancer types has provided promising results, but only a limited number of patients respond. Therefore, biomarkers to identify these responding patients are urgently needed. Methods: The GeparNuevo was a randomized, double-blind phase II trial in which triple-negative breast cancer (TNBC) patients were treated with neoadjuvant chemotherapy (NACT) consisting of nanoparticle albumin-bound paclitaxel in an initial phase followed by treatment with epirubicin and cyclophosphamide. Placebo or durvalumab were given throughout the neo-adjuvant treatment and in the “window” sub-cohort also prior to chemotherapy. Primary objective of this report was to evaluate changes in the blood immune cell repertoires of TNBC patients receiving durvalumab (anti-PD-L1) versus placebo in combination with NACT. At up to 4 different time points during therapy, blood samples were taken and underwent immunomonitoring using multicolor flow cytometry. The absolute counts of the major immune cell subtypes in the blood as well as the frequencies of different immune cell subpopulations and their functional phenotypes along treatment were determined and correlated to clinico-pathologic characteristics of the patients and to treatment response. Results: 120 out of 174 patients included in the GeparNuevo trial underwent blood immunomonitoring; 63 patients belonged to the “window” sub-cohort. Durvalumab administration almost completely blocked the detection of the inhibitory ligand PD-L1 and induced changes in the composition of the immune cell subpopulations. Evaluation of the “window” sub-cohort, in which an enhanced, but not significant pathological clinical response was observed within the immunomonitored patients, identified different markers correlating with clinical response to durvalumab. Higher frequencies of CD4+ T cells at recruitment as well as increased frequencies of T cells bearing the gamma delta TCR along treatment were some of the characteristics of patients responding to durvalumab treatment. Conclusions: The flow cytometry-based immunomonitoring of the clinical trial identified different immune-relevant biomarkers at recruitment as well as during treatment that predict clinical response to durvalumab. After validation of this data in an independent patient cohort, these markers could be implemented for an improved patient stratification to immunotherapy.

Citation Format: Chiara Massa, Thomas Karn, Karsten Weber, Andreas Schneeweiss, Claus Hanusch, Jens-Uwe Blohmer, Dirk-Michael Zahm, Christian Jackisch, Marion van Mackelenbergh, Jörg Thomalla, Frederik Marmé, Jens Huober, Volkmar Müller, Christian Schem, Anja Müller, Elmar Stickeler, Katharina Biehl, Peter A. Fasching, Michael Untch, Sibylle Loibl, Carsten Denkert, Barbara Seliger. Immunological and clinical consequences of durvalumab treatment in combination to neoadjuvant chemotherapy in triple-negative breast cancer patients [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 PD9-04.

Characterization of Hormone Receptor and HER2 Status in Breast Cancer Using Mass Spectrometry Imaging

Immunohistochemical evaluation of estrogen receptor, progesterone receptor, and human epidermal growth factor receptor-2 status stratify the different subtypes of breast cancer and define the treatment course. Triple-negative breast cancer (TNBC), which does not register receptor overexpression, is often associated with worse patient prognosis. Mass spectrometry imaging transcribes the molecular content of tissue specimens without requiring additional tags or preliminary analysis of the samples, being therefore an excellent methodology for an unbiased determination of tissue constituents, in particular tumor markers. In this study, the proteomic content of 1191 human breast cancer samples was characterized by mass spectrometry imaging and the epithelial regions were employed to train and test machine-learning models to characterize the individual receptor status and to classify TNBC. The classification models presented yielded high accuracies for estrogen and progesterone receptors and over 95% accuracy for classification of TNBC. Analysis of the molecular features revealed that vimentin overexpression is associated with TNBC, supported by immunohistochemistry validation, revealing a new potential target for diagnosis and treatment.

Prophylaxis of Neutropenia with Lipegfilgrastim in Breast Cancer Patients with Dose-Dense Chemotherapy: Results of a Noninterventional Study on Therapeutic Routine in Germany (NADENS)

Introduction

Noninterventional study (NIS) on application and effectiveness of primary G-CSF prophylaxis with lipegfilgrastim in primary breast cancer patients undergoing dose-dense (dd) or intense-dose-dense (idd) chemotherapy (CTx) regimen in daily clinical practice.

Methods

Prospective, multicenter, single-arm, NIS in 41 private practices and 27 hospitals in Germany.

Results

Data analysis of 282 patients with a mean age of 49 years (93.6% of patients <65 years) was performed. Hormone receptor status was triple negative in 29.8% of patients, and 81.9% of patients were HER2 negative. A total of 73.8% of patients received "EC dd → taxane CTx." Patients received lipegfilgrastim prophylaxis in 97.5% of 1,121 documented dd/idd cycles. Overall, the study registered 275 events of SN (CTCAE grade 3 or 4) and 9 events of FN. During the first dd cycle, SN occurred in 33.3% and FN in 1.1% of patients. CTx delay or dose reduction due to neutropenia was required in 2.5% of patients during the 4 dd cycles with lipegfilgrastim support. Overall, 314 adverse events (AEs) were reported from 107 patients and 27 serious AEs from 21 patients. None of the SAEs was "fatal," and CTCAE grade was mostly (89.6%) assessed as "1" or "2." According to the treating physicians, 99.3% of all patients benefitted from lipegfilgrastim prophylaxis, and tolerability was mostly rated "very good" or "good."

Conclusion

These results suggest that primary lipegfilgrastim prophylaxis is effective and safe in clinical routine and is beneficial in primary breast cancer patients undergoing dd/idd-ETC CTx.

Low TMB as predictor for additional benefit from neoadjuvant immune checkpoint inhibition in triple-negative breast cancer

581

Background: It is commonly anticipated that a high tumor mutational burden (TMB) is a predictor of response to immune checkpoint blockade (ICB). We previously showed that triple-negative breast cancer (TNBC) from the GeparNuevo study with high TMB displayed increased response both to neoadjuvant chemo-ICB with durvalumab but also to chemotherapy alone, with no significant interaction with treatment arm (Karn et al. Ann Oncol 2020). In contrast, we also observed that cases with very low TMB more often displayed a pCR after treatment with chemo-ICB than with chemotherapy alone. This may in fact suggest a benefit of ICB to those TNBC with rather low TMB. Methods: We have analyzed the distant disease-free survival (DDFS) of GeparNuevo patients according to TMB and treatment arm (neoadjuvant chemotherapy plus durvalumab or chemotherapy plus placebo). For TMB (mut/Mb) we applied the identical cutoff of the upper tertile as in our previous analysis. Results: The median follow-up of the time-to-event data was 43.7 months. Data of TMB was available in 149 of 174 patients. We found that within the high-TMB tumors (durvalumab: n=27; placebo: n=23), DDFS was similar between both arms of the trial (durvalumab vs. placebo: HR (hazard ratio) 0.95 [95%CI 0.19-4.69], p=0.95). Strikingly however, within the low-TMB group (durvalumab: n=47; placebo: n=52) we observed a significantly better DDFS in the durvalumab-chemotherapy combination arm, in contrast to the arm treated only with chemotherapy (durvalumab vs. placebo: HR 0.23 [95%CI 0.06-0.79], p=0.02; interaction test for TMB and treatment arm p=0.17). The observation was also robust to alternative TMB cutoffs. Similar results were obtained for invasive disease-free survival. Conclusions: Our results show, in contrast to other published data, that patients with early TNBC and low TMB/neoantigen counts may benefit from short-term neoadjuvant durvalumab treatment, while for those with high TMB, durvalumab plus chemotherapy does not improve efficacy over chemotherapy alone.

Abstract OT2-29-01: neoMono - An adaptive randomized neoadjuvant two arm trial in patients with TNBC comparing a mono atezolizumab window followed by atezolizumab and chemotherapy with atezolizumab and chemotherapy

Background: Improvement of systemic treatment of TNBC represents an unmet medical need. Recently, targeted therapy of regulatory immune pathways has become an important option in the treatment of numerous malignancies including breast cancer. Neoadjuvant trials combining chemotherapy and checkpoint inhibitors (KEYNOTE-522 and IMPASSION031) have demonstrated a meaningful benefit regarding pathological complete remission (pCR) and event-free survival (EFS) for the addition of PD-1- and PD-L1-inhibitors to chemotherapy among patients with TNBC, respectively. In addition, initial analyzes have presented promising results regarding event-free survival. In the neoadjuvant GeparNuevo trial only a subgroup of patients with TNBC, receiving a 2-week checkpoint inhibitor monotherapy window before the start of neoadjuvant chemotherapy in combination with checkpoint inhibition, achieved a pCR benefit as compared to patients treated with neoadjuvant chemotherapy alone. Trial Design: NeoMono is a phase 2 randomized multicenter trial recruiting male and female patients with primary TNBC (defined as ER/PR &lt; 10% and HER2 negative). Neoadjuvant treatment in Arm A and B consists of Atezolizumab 1200 mg every 3 weeks in addition to neoadjuvant chemotherapy (i.e. 12 x Carboplatin and Paclitaxel q1w followed by Epirubicin and Cyclophosphamide q3w) In Arm A this therapy is preceded by Atezolizumab 840 mg q2w (Atezolizumab mono window). Study goals are the comparison of efficacy and safety of neoadjuvant chemotherapy with Atezolizumab with and without Atezolizumab two-week window (primary endpoint: pCR) and the identification of biomarkers predicting (early) response to or resistance against Atezolizumab. The broad translational program of the neoMono trial aims at identifying these biomarkers on tumor and patient level. The neoMono statistical design adapts the idea of a proof-of-concept trial and uses Bayesian posterior and predictive probabilities for inference about the primary hypothesis. Up to four planned efficacy interim analyses provide decision points for early stopping for success or futility. The expected maximum number of patients to be recruited is 458.

Citation Format: Cornelia Kolberg-Liedtke, Johannes Schumacher, Ramona Erber, Michael Braun, Bernhard Heinrich, Oliver Hoffmann, Peter Fasching, Helmut Forstbauer, Anke Kleine-Tebbe, Georg Kunz, Michael Lux, Joachim Rom, Christian Schem, Nicole Stahl, Arndt Hartmann, Sabine Kasimir-Bauer, Hans-Christian Kolberg. neoMono - An adaptive randomized neoadjuvant two arm trial in patients with TNBC comparing a mono atezolizumab window followed by atezolizumab and chemotherapy with atezolizumab and chemotherapy [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 OT2-29-01.

Abstract P4-04-14: Immunological markers in patients with breast cancer occurring during pregnancy - Results from GBG BCP study

Background: Breast cancer is one of the most common malignancies during pregnancy. Although breast cancer in pregnancy (BCP) is still a rare event (1 in 3000 to 10000 pregnancies), the incidence is likely to increase as more women tend to delay childbearing into later life and the overall lifetime cancer risk increases with age. Pregnancy presents a complex and unique immunological condition. Pregnant women are widely considered to be in an immunosuppressed state, making them more susceptible to infectious diseases. Recent studies have shown similarities between malignancies and the semi-allogenic fetus in terms of immune evasion strategies, for example upregulation of non-classical human leukocyte antigen G (HLA-G). The loss or downregulation of HLA class I is also a way to escape anti-tumor immunity. The aim of this study was to investigate the tumor biology and immunology of pregnant breast cancer patients and the impact of pregnancy on the immunological characteristics of the breast cancer. Methods: 196 of 2831 patient enrolled in the BCP registry (GBG 29) had available tumor material. After identifying representative tumor regions, tissue microarrays (TMAs) of formalin-fixed paraffin embedded core biopsies or surgical specimens from 126 pregnant breast cancer patients treated with neo-(adjuvant) chemotherapy were constructed. TMAs were stained via immunohistochemistry to assess estrogen receptor (ER), progesterone receptor (PgR), human epidermal growth factor receptor 2 (HER2), Ki-67 (&lt;20% vs ≥20%), and immune markers HLA class I (≤5% vs &gt;5%), HLA-G (≤5% vs &gt;5%), TIGIT and Nectin4 as well as hematoxylin-eosin for the prevalence of tumor-infiltrating lymphocytes (TILs, ≤30% vs 31-60% vs &gt;60%). Results: Median age of the patients was 34 (range 26 - 47) years. At the time of diagnosis 50.8% of patients had cT2 tumor and 36.8% nodal involvement. The pre-dominant histological tumor type was ductal or ductal-lobular-invasive carcinoma (89.5%) with poor differentiation (G3: 68.3%). 78.5% of patients were centrally HER2 negative, 42.1% ER-positive and 53.2% PgR-positive; 53.3% had a high expression of Ki-67 (≥20%). With regards to breast cancer subtypes, most patients had either TNBC (34.7%) or HER2-/HR+ breast cancer (43.8%). HLA class I expression (≤5%) was downregulated in 21.3% of patients while 46.3% showed upregulation of HLA-G expression (&gt;5%). Analyzing HLA-G as continuous variable demonstrated an increased but not significant median expression of HLA-G in T3-4 (N=27) compared to T1-2 (N=99) tumor stage (12.4% vs 3.4%, p=0.226). TILs were detected in 62 out of 126 analyzed patients, of whom 93.5% (N=58) had a low expression of TILs (≤30%). Analysis of TIGIT and Nectin4 is ongoing. Conclusions: The high prevalence of low TILs expression in breast cancer during pregnancy might be a sign of reduced maternal immunity associated with pregnancy. HLA class I downregulation detected in our cohort suggests that it is an independent factor of anti-tumor immunity. Additional immune markers and data from a non-pregnant cohort are currently evaluated to make valid conclusions regarding gestational effects on classical and immunological tumor features. Those data will be presented at the meeting.

Citation Format: Kristin Galas, Moritz Gleitsmann, Julia Rey, Christine Solbach, Isabell Witzel, Thomas Karn, Andreas Schneeweiss, Bruno Sinn, Tanja Fehm, Carsten Denkert, Volkmar Müller, Anne-Sophie Litmeyer, Christian Schem, Paul Jank, Frederik Marmé, Jenny Furlanetto, Peter A. Fasching, Elmar Stickeler, Olaf Ortmann, Marion van Mackelenbergh, Valentina Nekljudova, Sibylle Loibl. Immunological markers in patients with breast cancer occurring during pregnancy - Results from GBG BCP study [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 P4-04-14.

DNA methylation profiling identifies two distinct subgroups in breast cancers with low hormone receptor expression, mainly associated with HER2 amplification status

Background

Current clinical guidelines suggest that breast cancers with low hormone receptor expression (LowHR) in 1–10% of tumor cells should be regarded as hormone receptor positive. However, clinical data show that these patients have worse outcome compared to patients with hormone receptor expression above 10%. We performed DNA methylation profiling on 23 LowHR breast cancer specimens, including 13 samples with HER2 amplification and compared our results with a reference breast cancer cohort from The Cancer Genome Atlas to clarify the status for this infrequent but important patient subgroup.

Results

In unsupervised clustering and dimensionality reduction, breast cancers with low hormone receptor expression that lacked HER2 amplification usually clustered with triple negative breast cancer (TNBC) reference samples (8/10; “LowHR TNBC-like”). In contrast, most specimens with low hormone receptor expression and HER2 amplification grouped with hormone receptor positive cancers (11/13; “LowHR HRpos-like”). We observed highly similar DNA methylation patterns of LowHR TNBC-like samples and true TNBCs. Furthermore, the Ki67 proliferation index of LowHR TNBC-like samples and clinical outcome parameters were more similar to TNBCs and differed from LowHR HRpos-like cases.

Conclusions

We here demonstrate that LowHR breast cancer comprises two epigenetically distinct groups. Our data strongly suggest that LowHR TNBC-like samples are molecularly, histologically and clinically closely related to TNBC, while LowHR HRpos-like specimens are closely related to hormone receptor positive tumors.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13148-021-01176-5.

Correction: MGMT promoter methylation in triple negative breast cancer of the GeparSixto trial

[This corrects the article DOI: 10.1371/journal.pone.0238021.].

TGFB-induced factor homeobox 1 (TGIF) expression in breast cancer

BACKGROUND

Breast cancer (BC) is the most frequent female cancer and preferentially metastasizes to bone. The transcription factor TGFB-induced factor homeobox 1 (TGIF) is involved in bone metabolism. However, it is not yet known whether TGIF is associated with BC bone metastasis or patient outcome and thus of potential interest.

METHODS

TGIF expression was analyzed by immunohistochemistry in 1197 formalin-fixed, paraffin-embedded tissue samples from BC patients treated in the GAIN (German Adjuvant Intergroup Node-Positive) study with two adjuvant dose-dense schedules of chemotherapy with or without bisphosphonate ibandronate. TGIF expression was categorized into negative/low and moderate/strong staining. Endpoints were disease-free survival (DFS), overall survival (OS) and time to primary bone metastasis as first site of relapse (TTPBM).

RESULTS

We found associations of higher TGIF protein expression with smaller tumor size (p = 0.015), well differentiated phenotype (p < 0.001) and estrogen receptor (ER)-positive BC (p < 0.001). Patients with higher TGIF expression levels showed a significantly longer disease-free (DFS: HR 0.75 [95%CI 0.59-0.95], log-rank p = 0.019) and overall survival (OS: HR 0.69 [95%CI 0.50-0.94], log-rank p = 0.019), but no association with TTPBM (HR 0.77 [95%CI 0.51-1.16]; p = 0.213). Univariate analysis in molecular subgroups emphasized that elevated TGIF expression was prognostic for both DFS and OS in ER-positive BC patients (DFS: HR 0.68 [95%CI 0.51-0.91]; log-rank p = 0.009, interaction p = 0.130; OS: HR 0.60 [95%CI 0.41-0.88], log-rank p = 0.008, interaction p = 0.107) and in the HER2-negative subgroup (DFS:HR 0.67 [95%CI 0.50-0.88], log-rank p = 0.004, interaction p = 0.034; OS: HR 0.57 [95%CI 0.40-0.81], log-rank p = 0.002, interaction p = 0.015).

CONCLUSIONS

Our results suggest that moderate to high TGIF expression is a common feature of breast cancer cells and that this is not associated with bone metastases as first site of relapse. However, a reduced expression is linked to tumor progression, especially in HER2-negative breast cancer.

TRIAL REGISTRATION

This clinical trial has been registered with ClinicalTrials.gov ; registration number: NCT00196872 .

Chemotherapy-induced ovarian failure in young women with early breast cancer: Prospective analysis of four randomised neoadjuvant/adjuvant breast cancer trials

BACKGROUND

Young women receiving chemotherapy for early breast cancer (EBC) have a high probability for ovarian failure, defined by chemotherapy-induced amenorrhea (CIA) as a surrogate. CIA is insufficiently reliable and reproducible. We analysed chemotherapy-induced ovarian failure (CIOF) by assessing hormone parameters, CIA, and antral follicle count (AFC).

METHODS

Blood samples of women aged ≤45 years treated with anthracycline/taxane-based chemotherapy for EBC from four neoadjuvant/adjuvant trials were collected at baseline, at the end of treatment (EOT), and at 6, 12, 18, and 24 months after EOT. Centrally assessed oestradiol (cutoff <52.2 ng/L) and follicle-stimulating hormone (cutoff >12.4IU/L) were used to define CIOF for patients with baseline premenopausal hormone levels, anti-Müllerian hormone (AMH), and AFC to assess ovarian reserve. Further analyses included CIA, regain of premenopausal hormone levels, and disease-free survival (DFS) also in subgroups.

RESULTS

Six hundred ninety-six patients aged ≤45 years had premenopausal hormone levels at baseline. Overall, 85.1% (592/696) experienced CIOF at EOT, and 147 of 592 had further hormone measurements after EOT. Of those, 32.7% (48/147) regained premenopausal hormone levels after 6 months, 57.9% (66/114) regained premenopausal hormone levels after 12 months, 83.0% (73/88) regained premenopausal hormone levels after 18 months, and 89.2% (74/83) regained premenopausal hormone levels after 24 months. After 24 months, 72.4% (21/29) of patients without CIOF and 100% (14/14) with CIOF had low AMH levels. Four-year DFS without CIOF versus CIOF was 65.9% versus 84.6% (hazard ratio [HR] = 2.09, 95% confidence interval [CI]: 1.37-3.19; P < 0.001); in hormone receptor positive 61.8% versus 87.5% (HR = 2.69, 95% CI: 1.57-4.60; P < 0.001); in <30 years 68.3% versus 92.6% (HR = 4.87, 95% CI: 1.05-22.63; P = 0.026).

CONCLUSION

Most premenopausal women experienced CIOF after chemotherapy for EBC. After 2 years, nearly all regain premenopausal hormone levels. CIOF was associated with better DFS, especially in patients with hormone receptor-positive EBC or aged <30 years.

ADAPTlate: A randomized, controlled, open-label, phase III trial on adjuvant dynamic marker—Adjusted personalized therapy comparing abemaciclib combined with standard adjuvant endocrine therapy versus standard adjuvant endocrine therapy in (clinical or genomic) high-risk, HR+/HER2- early breast cancer

TPS598

Background: The WSG ADAPT trial program addresses the individualization of (neo)adj. decision-making in EBC. The ADAPT umbrella trial established early predictive molecular surrogate markers for response after a 3-wk endocrine treatment (ET) to omit chemotherapy (CT) in a cohort of early high-risk HR+/HER2- pts. ADAPTlate seeks to improve adj. therapy for pts. at high risk for late disease recurrence, who completed definite locoregional therapy (with / without (neo-)adj. CT) and are under adj. ET. This high-risk population does not derive optimal benefit from standard ET, develops secondary ET resistance, and late recurrences. Methods: Prospective, multi-center, interventional, two-arm, open, randomized, controlled adj. phase III trial (NCT04565054) to investigate additional benefit from 2 years of the CDK4/6-inhibitor abemaciclib combined with ET compared to ET alone in pts. with high-risk HR+/HER2- EBC. Abemaciclib demonstrated to improve outcome in metastatic BC and even in EBC when given as part of primary therapy. Primary objective is to demonstrate superiority of iDFS of abemaciclib + ET vs. standard ET. Secondary objectives include OS, dDFS, occurrence of CNS metastases, QoL, and translational research. Recruitment started in 9/2020 to screen 1250 pts. and to randomize 903 pts. in a ratio 3:2. Until date of submission, 33 pts. were screened and 22 randomized. Pre-/postmenopausal pts. with histologically confirmed invasive HR+/HER2- EBC, 2-6 y after primary diagnosis, with either known high clinical risk (c/pN 2-3 OR high CTS score in pN 0-1 OR non-pCR after neoadj. CT in cN 1 or G3 tumors OR G3 and Ki-67 ≥ 40% in pN 0-1) or known high genomic risk (RS >25 in c/pN 0, RS >18 in c/pN 1 OR high risk Prosigna, EPclin or Mammaprint in pN 0-1) or intermediate clinical, but unknown genomic risk (luminal B-like (G3 or Ki-67 ≥20%) in c/pN 0-1 AND either RS >25 in c/pN 0 or RS >18 in c/p N1 in screening) will be eligible. Treatment duration is 2 years for the abemaciclib + ET (premenopausal: AI + GnRH) arm, followed by at least 3-6 years ET alone. Pts. in control arm will receive 5-8-years ET at investigator´s choice. ePROs are collected using CANKADO. Translational analyses: Exploratory tissue biomarker research to assess alterations in molecular markers. Liquid biopsies (CTC/ctDNA/ctRNA) will be assessed for mutations and gene expression relevant for HR+/HER2- EBC using an appropriate technology at time of testing. Conclusions: ADAPTlate seeks to evaluate whether Abemaciclib + ET is superior to ET alone in pts. with clinical or genomic high-risk EBC even 2-6 years after initial diagnosis. Translational research aims at assessing potential mechanisms of resistance to endocrine and/or CDK4/6 targeted therapy. Clinical trial information: NCT04565054.

Immune-related Gene Expression Predicts Response to Neoadjuvant Chemotherapy but not Additional Benefit from PD-L1 Inhibition in Women with Early Triple-negative Breast Cancer

PURPOSE

We evaluated mRNA signatures to predict response to neoadjuvant PD-L1 inhibition in combination with chemotherapy in early triple-negative breast cancer.

EXPERIMENTAL DESIGN

Targeted mRNA sequencing of 2,559 transcripts was performed in formalin-fixed, paraffin-embedded samples from 162 patients of the GeparNuevo trial. We focused on validation of four predefined gene signatures and differential gene expression analyses for new predictive markers.

RESULTS

Two signatures [GeparSixto signature (G6-Sig) and IFN signature (IFN-Sig)] were predictive for treatment response in a multivariate model including treatment arm [G6-Sig: OR, 1.558; 95% confidence interval (CI), 1.130-2.182; P = 0.008 and IFN-Sig: OR, 1.695; 95% CI, 1.234-2.376; P = 0.002), while the CYT metric predicted pathologic complete response (pCR) in the durvalumab arm, and the proliferation-associated gene signature in the placebo arm. Expression of PD-L1 mRNA was associated with better response in both arms, indicating that increased levels of PD-L1 are a general predictor of neoadjuvant therapy response. In an exploratory analysis, we identified seven genes that were higher expressed in responders in the durvalumab arm, but not the placebo arm: HLA-A, HLA-B, TAP1, GBP1, CXCL10, STAT1, and CD38. These genes were associated with cellular antigen processing and presentation and IFN signaling.

CONCLUSIONS

Immune-associated signatures are associated with pCR after chemotherapy, but might be of limited use for the prediction of response to additional immune checkpoint blockade. Gene expressions related to antigen presentation and IFN signaling might be interesting candidates for further evaluation.

Reconstructing tumor history in breast cancer: signatures of mutational processes and response to neoadjuvant chemotherapy⋆

BACKGROUND

Different endogenous and exogenous mutational processes act over the evolutionary history of a malignant tumor, driven by abnormal DNA editing, mutagens or age-related DNA alterations, among others, to generate the specific mutational landscape of each individual tumor. The signatures of these mutational processes can be identified in large genomic datasets. We investigated the hypothesis that genomic patterns of mutational signatures are associated with the clinical behavior of breast cancer, in particular chemotherapy response and survival, with a particular focus on therapy-resistant disease.

PATIENTS AND METHODS

Whole exome sequencing was carried out in 405 pretherapeutic samples from the prospective neoadjuvant multicenter GeparSepto study. We analyzed 11 mutational signatures including biological processes such as APOBEC-mutagenesis, homologous recombination deficiency (HRD), mismatch repair deficiency and also age-related or tobacco-induced alterations.

RESULTS

Different subgroups of breast carcinomas were defined mainly by differences in HRD-related and APOBEC-related mutational signatures and significant differences between hormone-receptor (HR)-negative and HR-positive tumors as well as correlations with age, Ki-67 and immunological parameters were observed. We could identify mutational processes that were linked to increased pathological complete response rates to neoadjuvant chemotherapy with high significance. In univariate analyses for HR-positive tumors signatures, S3 (HRD, P < 0.001) and S13 (APOBEC, P = 0.001) as well as exonic mutation rate (P = 0.002) were significantly correlated with increased pathological complete response rates. The signatures S3 (HRD, P = 0.006) and S4 (tobacco, P = 0.011) were prognostic for reduced disease-free survival of patients with chemotherapy-resistant tumors.

CONCLUSION

The results of this investigation suggest that the clinical behavior of a tumor, in particular, response to neoadjuvant chemotherapy and disease-free survival of therapy-resistant tumors, could be predicted by the composition of mutational signatures as an indicator of the individual genomic history of a tumor. After additional validations, mutational signatures might be used to identify tumors with an increased response rate to neoadjuvant chemotherapy and to define therapy-resistant subgroups for future therapeutic interventions.

Fixed-dose combination of pertuzumab and trastuzumab for subcutaneous injection plus chemotherapy in HER2-positive early breast cancer (FeDeriCa): a randomised, open-label, multicentre, non-inferiority, phase 3 study

BACKGROUND

A subcutaneous formulation of pertuzumab and trastuzumab with recombinant human hyaluronidase in one ready-to-use, fixed-dose combination vial (pertuzumab, trastuzumab, and hyaluronidase-zzxf) was approved by the US Food and Drug Administration (FDA) on June 29, 2020. We report the primary analysis of the FeDeriCa study, which was designed to assess the pharmacokinetics, efficacy, and safety of the fixed-dose subcutaneous formulation compared to intravenous pertuzumab plus trastuzumab in patients with HER2-positive early breast cancer in the neoadjuvant-adjuvant setting.

METHODS

FeDeriCa, a randomised, open-label, international, multicentre, non-inferiority, phase 3 study, was done across 106 sites in 19 countries. Patients aged 18 years or older with an Eastern Cooperative Oncology Group performance status of 0 or 1, HER2-positive, operable, locally advanced, or inflammatory stage II-IIIC breast cancer, and a left ventricular ejection fraction of 55% or more were randomly assigned (1:1), using a voice-based or web-based response system, to receive intravenous pertuzumab (840 mg loading dose, followed by 420 mg maintenance doses) plus intravenous trastuzumab (8 mg/kg loading dose, followed by 6 mg/kg maintenance doses) or the fixed-dose combination of pertuzumab and trastuzumab for subcutaneous injection (1200 mg pertuzumab plus 600 mg trastuzumab loading dose in 15 mL, followed by 600 mg pertuzumab plus 600 mg trastuzumab maintenance doses in 10 mL), both administered every 3 weeks with neoadjuvant chemotherapy. Patients were stratified by hormone receptor status, clinical stage, and chemotherapy regimen. The investigator selected one of the two protocol-approved standard chemotherapy regimens before randomisation. Four cycles of HER2-targeted therapy were administered concurrently with the taxane. After surgery, patients continued the HER2-targeted therapy to receive an additional 14 cycles (total of 18). The primary endpoint was non-inferiority of the cycle 7 pertuzumab serum trough concentration (C_trough; ie, cycle 8 predose pertuzumab concentration) within the fixed-dose combination for subcutaneous injection versus intravenous pertuzumab plus trastuzumab in the per-protocol pharmacokinetic population (all enrolled patients who adhered to prespecified criteria for pharmacokinetic assessment). Non-inferiority was concluded if the lower bound of the 90% CI of the geometric mean ratio was 0·8 or higher. The safety population included all patients who received at least one dose of study medication, including chemotherapy or HER2-targeted therapy. Enrolment, neoadjuvant therapy, and surgery have been completed; adjuvant treatment and follow-up are ongoing. The trial is registered with ClinicalTrials.gov, NCT03493854.

FINDINGS

Between June 14, 2018, and Dec 24, 2018, 252 patients were randomly assigned to the intravenous infusion group and 248 to the fixed-dose combination group. The geometric mean ratio of pertuzumab serum C_trough subcutaneous to serum C_trough intravenous was 1·22 (90% CI 1·14-1·31). The most common grade 3-4 adverse events occurring during neoadjuvant treatment with HER2-targeted therapy plus chemotherapy in 5% or more of patients were neutropenia (34 [13%] of 252 patients in the intravenous infusion group vs 35 [14%] of 248 patients in the fixed-dose combination group), decreased neutrophil count (31 [12%] vs 27 [11%]), febrile neutropenia (14 [6%] vs 16 [6%]), diarrhoea (12 [5%] vs 17 [7%]), and decreased white blood cell count (18 [7%] vs nine [4%]). At least one treatment-related serious adverse event was reported in 25 (10%) patients in the intravenous infusion group and 26 (10%) patients in the fixed-dose combination group. One patient in each treatment group had an adverse event that led to death (urosepsis in the intravenous infusion group and acute myocardial infarction in the fixed-dose combination group); neither death was related to HER2-targeted therapy.

INTERPRETATION

The study met its primary endpoint: the fixed-dose combination of pertuzumab and trastuzumab for subcutaneous injection provides non-inferior cycle 7 pertuzumab serum C_trough concentrations to intravenous pertuzumab plus trastuzumab in the neoadjuvant setting with comparable total pathological complete response rates, supporting the FDA approval. Safety was similar between treatment groups, and in line with other pertuzumab, trastuzumab, and chemotherapy trials. Follow-up is ongoing for long-term outcomes, including efficacy and long-term safety.

FUNDING

F Hoffmann-La Roche and Genentech.

Cardiotoxicity and Cardiovascular Biomarkers in Patients With Breast Cancer: Data From the GeparOcto-GBG 84 Trial

Background Patients with breast cancer can be affected by cardiotoxic reactions through cancer therapies. Cardiac biomarkers, like NT-proBNP (N-terminal pro-B-type natriuretic peptide) and high-sensitivity cardiac troponin T, might have predictive value. Methods and Results Echocardiography, ECG, hemodynamic parameters, NT-proBNP and high-sensitivity cardiac troponin T were assessed in 853 patients with early-stage breast cancer randomized in the German Breast Group GeparOcto-GBG 84 phase III trial. Patients received neo-adjuvant dose-dense, dose-intensified epirubicin, paclitaxel, and cyclophosphamide (iddEPC group, n=424) or paclitaxel, non-pegylated doxorubicin, and in triple negative breast cancer, (paclitaxel, non-pegylated doxorubicin, carboplatin group, n=429) treatment for 18 weeks. Patients positive for human epidermal growth receptor 2 (n=354, 41.5%) received monoclonal antibodies on top of allocated therapy; 119 (12.9%) of all patients showed a cardiotoxic reaction during therapy (15 [1.8%] using a more strict definition). Presence of cardiotoxic reactions was irrespective of treatment allocation (P=0.31). Small but significant increases in NT-proBNP developed early in patients with a cardiotoxic reaction as compared with those without in whom NT-proBNP rose only towards the end of therapy (P=0.04). High-sensitivity cardiac troponin T rose early in both groups. Logistic regression showed that NT-proBNP (odds ratio [OR], 1.03; 95% CI, 1.008-1.055; P=0.01) and hemoglobin (OR, 1.31; 95% CI, 1.05-1.63; P=0.02) measured at 6 weeks after treatment initiation were significantly associated with cardiotoxic reactions. Conclusions NT-proBNP and hemoglobin are significantly associated with cardiotoxic reactions in patients with early-stage breast cancer undergoing dose-dense and dose-intensified chemotherapy, but high-sensitivity cardiac troponin T is not. Registration URL: http://www.clinicaltrials.gov; Unique identifier: NCT02125344.

Differential effect on different immune subsets of neoadjuvant chemotherapy in patients with TNBC

Background

Triple-negative breast cancer (TNBC) is the most aggressive form of breast cancer (BC). Due to the absence of targets such as HER2 or hormone receptors, early TNBC is treated with surgery and chemotherapy. Since TNBC is also considered the most immunogenic type of BC with tumor infiltrating lymphocytes that are predictive for chemotherapy response and prognostic for patients′ survival, many different immunotherapeutic strategies are currently explored in clinical trials for the treatment of this disease. In order to efficiently combine chemotherapy with immunotherapy, it is important to evaluate the effect of chemotherapy on immune cells in vivo.

Methods

Peripheral blood was taken from 56 patients with TNBC undergoing neoadjuvant chemotherapy with nanoparticle albumin-bound paclitaxel (Nab-Pac) followed by epirubicin and cyclophosphamide (EC) at three different time points. Multicolor flow cytometry was used to characterize the immune cell composition and functional properties along neoadjuvant chemotherapy.

Results

Whereas the first phase of the neoadjuvant chemotherapy did not significantly alter the patients′ immune cell composition, after the second phase of chemotherapeutic administration most B cells (>90%) were lost and the frequency of natural killer (NK) cells and CD4⁺ T lymphocytes decreased approximately to 50%. In contrast, the frequency of CD8⁺ T cells were less affected.

Conclusions

Despite late consequences of Nab-Pac cannot be ruled out, these data suggest that different chemotherapeutics might have distinct effects on the immune cell repertoire and that different immune cell populations exhibit a specific susceptibility to these chemotherapies with B and NK cells being more affected than T cells. This might also have an impact on the combination of chemotherapies with immunotherapies.

Trial registration number

NCT02685059.

Cytoplasmic levels of high mobility group A2 determine survival prognoses in breast cancer patients

BACKGROUND

High mobility group A proteins are involved in chromatin remodeling, thereby influencing multiple fundamental biological processes. HMGA2 has been linked to oncogenic traits among a variety of malignancies.

OBJECTIVE

To determine the prognostic implications of subcellular distribution patterns of HMGA2 in breast cancer.

METHODS

Nuclear and cytoplasmic HMGA2 was evaluated in 342 breast cancer specimens and matched with clinico-pathological parameters.

RESULTS

Overall and cytoplasmic, but not nuclear, levels of HMGA2 correlated with better survival prognoses in our collective (hazard ratio (HR) 0.34, P = 0.001 and HR 0.34, P < 0.001, respectively). The protective effect of cytoplasmic HMGA2 persisted in the Luminal A and triple negative breast cancer subgroups. Evaluating Luminal A and B subgroups jointly, only cytoplasmic, but not overall or nuclear HMGA2 levels were associated with better survival (HR 0.42, 95% confidence interval 0.21, 0.86, P = 0.017), irrespective of tumor size and node status. The addition of HMGA2 overall and cytoplasmic scores strengthened the prognostic selectivity in a model of conventional breast cancer risk factors. No predictive significance with regard to endocrine or chemoendocrine therapies was observed.

CONCLUSION

Unexpectedly, we found a favorable survival probability upon overall levels of HMGA2 in our breast cancer collective, which was predominantly determined by the presence of HMGA2 in the cytoplasm.

Abstract P6-10-04: Landscape of immune-cell signatures in early high-risk breast cancer (BC) reveals clinically-relevant enrichment of immune subpopulations

Background: Immunosurveillance suppression, evasion, or avoidance, has emerged as a key targetable hallmark of cancer, driven by e.g. checkpoint expression, T-cell exhaustion, and immunosuppressive tumor microenvironment (TME). Many of these processes generate defined combinations of immune-cell infiltrates at the tumor site, which can be detected by immunohistochemistry (IHC), CyTOF, or more recently can be inferred from gene-expression deconvolution. While significant work has been done to study gene signatures in the TME, the clinical relevance of such immune-cell gene signature on therapy has not been studied to a great extent. We investigate the hypothesis that the individual patterns of immune-cell signatures determine the clinical behavior of breast cancer (BC), in particular response to neoadjuvant chemotherapy. Methods: We performed a retrospective-prospective analysis of a subset of the GeparSepto study (NCT01583426) in which women with primary invasive BC were randomized to either nab-paclitaxel or solvent-based paclitaxel followed by EC. This study was limited to 279 HER2- patients with sufficient quality sample remaining to perform whole-transcriptome RNAseq (~200 × 106 reads per tumor). Immune activity in the TME was inferred by comparing expression of 23 immune-cell-specific gene signatures derived by Bindea et al. (Immunity, 2013) to those from a background population of 1467 similarly-profiled unselected tumor samples from the NantOmics database. Results: Within this cohort the most predominant high immune-cell signatures were for natural killer (NK) cells (71%), and regulatory T-cells (70%). Stimulatory T-cell signatures were high in approximately half of the population including Th2 (53%), effector-memory (53%), follicular helper (51%), Th1 (41%), and Gamma-delta T-cells (39%). While cytotoxic CD8+ T-cell signature was high in only 19.0% of patients, the signature for the CD56dim cytolytic subset of NK cells was high in 48.0% of patients. The most infrequently detected gene signatures were for innate response cell-types: Mast cells (7.5%), Macrophages (10.8%), immature dendritic cells (11.5%) and neutrophils (11.8%). Of the 23 immune signatures, 17 were significantly differentially activated in TNBC compared to hormone-receptor positive (HR+) patients (p&lt;0.05 respectively): 8/10 signatures more active in TNBC are associated with adaptive immune response (e.g. T-cell and B-cell signatures), whereas 5/7 signatures associated with HR+ are related to innate immune response (e.g. eosinophils and dendritic cells). Select adaptive immune signatures were associated with aggressive tumors: Elevated NK CD56dim, Th1, and activated dendritic cell (aDC), signatures were associated with grade 3 tumors as well as with elevated levels of Ki67 (p&lt;0.0001 respectively). The most predictive TME signature for paclitaxel-based therapy was T follicular helper cells (TFH) with DFS and OS hazard ratio of 0.62 (95% CI: 0.47-0.81; p=0.0004) and 0.55 (95% CI: 0.39-0.77; p=0.0005) respectively, as well as a 1.63 (95% CI: 1.12-2.36; p=0.0107) odds-ratio for achieving pCR. Conclusion: Whole-transcriptome sequencing in breast cancer FFPE core biopsies from clinical cohorts can be used to identify immune-cell signatures. Specifically, adaptive immunity through NK rather than T-cell response appears prevalent in high-risk TNBC. The patterns of these immune signatures, in particular the presence of T follicular helper cells, reflect the clinical behavior of breast cancer and might be used to identify tumors with an increased response rate to neoadjuvant chemotherapy.

Citation Format: Christopher Szeto, Carsten Denkert, Peter A Fasching, Stephen Benz, Karsten E Weber, Jan Budczies, Andreas Schneeweiss, Elmar Stickeler, Sabine Schmatloch, Christian Jackisch, Thomas Karn, Hans P Sinn, Mathias Warm, Marion van Mackelenbergh, Shahrooz Rabizadeh, Christian Schem, Ernst Heinmöller, Volkmar Müller, Frederik Marmé, Patrick Soon-Shiong, Valentina Nekljudova, Sibylle Loibl, Michael Untch. Landscape of immune-cell signatures in early high-risk breast cancer (BC) reveals clinically-relevant enrichment of immune subpopulations [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 P6-10-04.

Abstract PD4-07: Subcutaneous administration of the fixed-dose combination of trastuzumab and pertuzumab in combination with chemotherapy in HER2-positive early breast cancer: Primary analysis of the phase III, multicenter, randomized, open-label, two-arm FeDeriCa study

Background: Intravenous pertuzumab (P IV) + trastuzumab (H IV) + chemotherapy (CT) improves outcomes in patients (pts) with HER2-positive breast cancer, compared with H + CT.A new subcutaneous (SC) formulation, for the first time combining two monoclonal antibodies, P + H, with recombinant human hyaluronidase in one vial, was developed. This ready-to-use fixed-dose combination (PH FDC) is administered subcutaneously into the thigh over 5-8 minutes. The dose of H SC was confirmed in the phase III HannaH trial (NCT00950300) and the dose of P SC was established in a phase Ib study (NCT02738970). We report the first results from FeDeriCa (NCT03493854), which was designed to assess the pharmacokinetics, efficacy, and safety of this novel SC PH FDC compared with H IV + P IV in pts with HER2-positive early breast cancer in the neoadjuvant-adjuvant setting.

Methods: Pts with centrally confirmed HER2-positive invasive breast cancer (tumor &gt;2 cm, or node-positive disease; Stage II-IIIC) were randomized 1:1 to receive 8 cycles of CT in the neoadjuvant setting with H IV (loading dose 8 mg/kg, maintenance 6 mg/kg) + P IV (loading dose 840 mg, maintenance 420 mg) (Arm A) or CT per Arm A + PH FDC (loading dose 1200 mg P SC/600 mg H SC, maintenance 600 mg each; Arm B) administered q3w during cycles 5-8. CT was investigator’s choice of either 4 cycles of dose-dense doxorubicin + cyclophosphamide q2w → 4 cycles of weekly paclitaxel (total: 12 weeks), or 4 cycles of doxorubicin + cyclophosphamide q3w → 4 cycles of docetaxel q3w. Post-surgery, pts continued anti-HER2 treatment per randomization to complete 18 cycles. The primary objective was noninferiority (NI) of the pre-dose cycle 8 P serum trough concentration (Ctrough) within the PH FDC versus P IV (NI margin for the lower bound of the 90% confidence interval [CI] of the geometric mean ratio [GMR]: ≥0.8). Key secondary objectives were NI of pre-dose cycle 8 H Ctrough within the PH FDC versus H IV, total pathologic complete response in the breast and axilla (ypT0/is, ypN0; tpCR), and safety (primary cardiac events were defined as heart failure [New York Heart Association III + IV] with significant left ventricular ejection fraction [LVEF] decline; cardiac death. Secondary cardiac events were defined as LVEF decline ≥10% from baseline to below 50% and confirmed LVEF decline).

Results: Five-hundred pts were randomized (252 to Arm A, 248 to Arm B - ITT and safety populations) from 06/14/18-12/24/18 at 122 sites. At clinical cutoff (07/04/19), 242 pts (96.0%) in Arm A and 234 (94.4%) in Arm B completed the neoadjuvant treatment phase. Baseline pt demographics and disease characteristics were well balanced between arms.The study met its primary endpoint: P GMR was 1.22 (90% CI 1.14-1.31) with the lower limit of the 90% CI being above the prespecified NI margin of 0.8. H GMR was 1.33 (90% CI 1.24-1.43), meeting the NI criteria. tpCR rates were comparable between arms (59.5%; 95% CI 53.2-65.6 in Arm A and 59.7%; 95% CI 53.3-65.8 in Arm B) and were similar to other P + H + CT trials. Overall safety, including cardiac safety, was comparable between arms (Table). Safety was as expected for P + H + CT trials.

Conclusions: SC PH FDC demonstrated noninferior pre-dose cycle 8 P + H Ctrough to that of P IV + H IV, with comparable efficacy and safety. PH FDC offers a faster and simpler method of P + H administration for HER2-positive breast cancer.

Pts, %Arm A n = 252Arm B n = 248Any AE in &gt;50% of pts99.6100Alopecia70.277.0Nausea60.358.9Diarrhea55.258.5Grade ≥352.848.8Serious17.916.1CardiacPrimary00.8Secondary3.61.6Asymptomatic LVEF decline needing treatment/discontinuation4.02.0Death0.4*0.4** Unrelated to HER2 treatment

Citation Format: Antoinette R Tan, Seock-Ah Im, Andre Mattar, Ramon Colomer, Daniil Stroyakovskii, Zbigniew Nowecki, Michelino De Laurentiis, Jean-Yves Pierga, Kyung Hae Jung, Christian Schem, Sarah Heeson, Mahesh Shivhare, Whitney P. Kirschbrown, Eleonora Restuccia, Tanja Badovinac Crnjevic, Christian Jackisch. Subcutaneous administration of the fixed-dose combination of trastuzumab and pertuzumab in combination with chemotherapy in HER2-positive early breast cancer: Primary analysis of the phase III, multicenter, randomized, open-label, two-arm FeDeriCa study [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 PD4-07.

Abstract P1-10-01: Caveolin gene expression predicts for response and clinical outcomes of patients treated with preoperative paclitaxel-based chemotherapy regimens in early stage breast cancer

Background: Biomarkers are needed to prognosticate and predict efficacy of therapy for patients undergoing neoadjuvant chemotherapy for HER2-negative breast cancer (BC). Caveolin genes (CAV1, CAV2) are responsible for formation of caveolae, which are 50-100 nM membrane invaginations implicated in endocytosis and transcytosis of nutrients and substances, including albumin. Overexpression of caveolin family genes has been implicated in driving BC progression, but also in predicting response to nab-paclitaxel. We hypothesized that high CAV1/2 expression would correlate with poor clinical outcomes, but that patients with high CAV1/2 expression would have better outcomes with nab-paclitaxel based chemotherapy. Methods: We correlated tumor CAV1/2 RNA expression from available RNA-Seq data with pathologic complete response (pCR) and clinical outcomes (disease-free survival, DFS, and overall survival, OS) in the GeparSepto (G7) clinical trial, which randomized patients with early stage BC to preoperative paclitaxel versus nab-paclitaxel-based chemotherapy regimens. CAV1/2 log-transformed values were analyzed as a continuous variable and dichotomized about the mean for each gene. Multivariable logistic regression models were generated, and included age, T-stage, N-stage, tumor grade (G3 vs G1-2), Ki67 (continuous), and histology (non-ductal versus ductal). Results: There was RNA-Seq expression data available for 279 out of 810 HER2-negative patients, of whom 26.5% were hormone receptor (HR)-negative (triple negative). CAV1 and CAV2 expression values were directly correlated with each other (Pearson coefficient 0.452). There was no difference in CAV1 expression between HR-negative and HR-positive patients, but there was significant up-regulation of CAV2 expression (mean) in HR-negative patients (p=0.003). With regards to pCR, high CAV1/2 expression was associated with a strong benefit from nab-paclitaxel compared to paclitaxel (OR(CAV1)=4.92 (1.70-14.22) and OR(CAV2)=5.39 (1.76-16.47)) in contrast to low CAV1/2 expression (OR(CAV1)=0.94 (0.38-2.34) and OR(CAV2)=0.95 (0.39-2.29)) in multivariate modeling (tests for interaction p=0.023 and p=0.019). For CAV1 this effect continued beyond pCR with regards to survival: high CAV1 expression was associated with superior survival in the nab-paclitaxel arm (HR(DFS)=0.53 (0.27-1.05), HR(OS)=0.29 (0.11-0.77)) but not low CAV1 expression (HR(DFS)=1.37 (0.62-3.04), HR(OS)=2.47 (0.78-7.80)) in multivariate modeling (test for interaction p=0.077 (DFS) and p=0.005 (OS)). No significant interactions in hazard ratios for DFS and OS were detected for CAV2. With regard to prognostic effects, CAV2 expression was significantly associated with worse DFS and OS for all patients. In particular, high CAV2 expression was associated with poor prognosis for HR-negative patients in multivariate modeling (OR(DFS)=4.40 (1.44-13.46), OR(OS)=9.38 (1.13-77.75)), but not for HR-positive patients (OR(DFS)=1.60 (0.84-3.05), OR(OS)=2.05 (0.92-4.58)) (test for interaction p=0.125 and p=0.186). Conclusions: Higher CAV2 expression is associated with worse DFS and OS, in particular for HR-negative patients, confirming potential prognostic roles for CAV1/2. No significant differences in DFS and OS based on CAV1/2 expression were noted for patients who received nab-paclitaxel based treatment, but the odds of obtaining pCR were improved for patients with high CAV1/2 expression. Taken together, these findings suggest that CAV1/2 expression may offset the negative prognostic factor associated with higher CAV1/2 expression in patients treated with nab-paclitaxel regimens by enhancing the efficacy of treatment, perhaps through increased nab-paclitaxel endocytosis/transcytosis.

Citation Format: Terence Williams, Andreas Schneeweiss, Christian Jackisch, Changxian Shen, Karsten Weber, Peter Fasching, Carsten Denkert, Jenny Furlanetto, Ernst Heinmoller, Sabine Schmatloch, Thomas Karn, Christopher Szeto, Marion van Mackelenbergh, Valentina Nekljudova, Elmar Stickeler, Patrick Soon-Shiong, Christian Schem, Barbara Fleige, Volkmar Muller, Frederik Marme, Michael Untch, Sibylle Loibl. Caveolin gene expression predicts for response and clinical outcomes of patients treated with preoperative paclitaxel-based chemotherapy regimens in early stage breast cancer [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 P1-10-01.

Abstract P4-04-08: Histological and epigenetic analyses of placenta tissue from breast cancer patients and healthy participants

Background: Breast cancer is one of the most common malignancies during pregnancy. Guidelines for breast cancer treatment during pregnancy demonstrating that breast cancer during pregnancy can be treated similarly to non-pregnancy-associated breast cancer, except for hormonal and anti-HER2 therapies. Nonetheless, a decreased birth weight is often observed in newborns. Therefore, this project aims to analyze the effects of chemotherapy and the impact of cancer progression on the placenta. Methods: Placentas from breast cancer patients (n=63) and non-cancer participants (n=20) enrolled in Breast Cancer in Pregnancy (BCP) study were collected after delivery and embedded in paraffin. Sections were stained with Hematoxylin-Eosin (HE) and IHC (Ki-67, cPARP, p27Kip1); trophoblast morphology was evaluated by an established scoring system and distribution of immunohistochemical markers was assessed. Additionally, epigenetic analyses (cytosine methylation) for the following genes were performed: LINE-1 (general methylation), IGF2-H19 (birth weight), EPO (hypoxia), BDNF (neurobiological development), glucocorticoid receptor, HSD11B2 (inactivation of glucocorticoids), estrogen receptor, P-glycoprotein, CYP-3A4 (drug metabolism). Results: HE staining revealed significant damage of trophoblast nuclei and membranes in placentas from breast cancer patients compared to controls (mean score of damage 1.9/1.8 vs 0.8/0.7, p&lt;0.001). Simultaneously, mean proliferation index (Ki-67 positive cells/ 1000 trophoblasts) was reduced (36.3 vs 58.0, p&lt;0.001). In contrast, nuclear and cytoplasmic expression of the negative cell cycle regulator p27Kip1 was reduced (mean IRS score 1.0/0.9 vs 4.3/4.8, p&lt;0.001). No evidence of enhanced apoptosis was found. Epigenetic analyses showed significant differences in mean percentage of cytosine methylation of EPO (68.4% vs 71.1%, p&lt;0.05) and hCyp-3A4 (87.8% vs 90.0%, p&lt;0.01) gene. Altered methylation of CpG positions of LINE-1, IGF2-H19, HSD11B2, estrogen receptor and P-glycoprotein gene were found. Conclusions: Placentas from breast cancer patients seem to be harmed in contrast to placentas from normal pregnancies, shown by morphologic abnormalities and a decreased proliferation index. Nevertheless, no increase of apoptotic cells could be demonstrated. Altered expression of efflux pumps or drug-metabolizing enzymes might be a reason for good fetal tolerability of chemotherapy during pregnancy as methylation patterns were changed in P-glycoprotein and CYP-3A4 gene.

Citation Format: Karolin Fröhlich, Torsten Plösch, Fenja Seither, Volkmar Müller, Thomas Karn, Elmar Stickeler, Christian Schem, Christine Solbach, Amelie Lupp, Rikst N Verkaik-Schakel, Gitta Turowski, Peter Mallmann, Marion van Mackelenbergh, Bruno Sinn, Valentina Nekljudova, Carsten Denkert, Pamela Schittler, Udo Markert, Sibylle Loibl. Histological and epigenetic analyses of placenta tissue from breast cancer patients and healthy participants [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 P4-04-08.

Abstract OT3-14-02: Impact of CANKADO-based eHealth-support on quality of life in metastatic breast cancer patients treated with palbociclib and endocrine therapy - Precycle

Background: Efficacy and quality of life (QoL) are key factors when selecting therapies for metastatic breast cancer (MBC) patients. The addition of targeted oral agents such as CDK4/6 inhibitors to endocrine therapy is the new standard for hormone receptor (HR)+ HER2- MBC and substantially prolongs progression-free survival. However more complex oral medication in oncology might require substantial improvement of patient management. Despite several advantages of an oral treatment, patients become increasingly self-responsible and physician/patient contact is reduced. Adherence, maintaining patients’ satisfaction, and early detection and management of side effects become important challenges and new ways of continuous support for oncological patients are needed. An eHealth-based platform could help to support therapy management and physician-patient interaction. Methods: PRECYCLE is a multicenter, randomized, phase IV trial in HR+ HER2- MBC. All patients (n = 960) receive the CDK4/6 inhibitor palbociclib either in first (62.5%) or later line (37.5%) together with endocrine therapy (AI, fulvestrant) according to national guidelines. Primary study aim is the time to deterioration (TTD) of QoL in patients supported by two eHealth systems with substantially different functionality. To date (05/07/2019), 250 patients have been registered in all 72 participating centers and 230 randomized to the different study arms: - CANKADO inform with only a CANKADO-based eHealth service with a personal login, documentation of daily drug intake and passive text information (disease, treatment), but no further functions. vs. - CANKADO active with the fully functional CANKADO-based eHealth treatment support system (+ drug diary, QoL, AEs, automated recommendations, etc.) To evaluate QoL, the FACT-B questionnaire is completed at every visit. Primary objective is to test the hypothesis of superiority for TTD with regards to QoL (FACT-G scale) in patients supported by an eHealth therapy management system (CANKADO active) versus in those merely receiving eHealth-based information (CANKADO inform). As little is known about relationships between behavioral patterns (e.g. adherence), genetic background, and drug efficacy. The trial also includes a large translational program that aims at the discovery and validation of biomarkers concerning efficacy, toxicity, adherence and QoL. Recruitment is ongoing.

Citation Format: Tom Degenhardt, Peter Fasching, Diana Luftner, Volkmar Mueller, Christoph Thomssen, Christian Schem, Isabel Witzel, Thomas Decker, Hans Tesch, Sherko Kuemmel, Christoph Uleer, Rachel Wuerstlein, Christoph Riese, Timo Schinköthe, Ronald Kates, Johannes Schumacher, Nadia Harbeck, Marcus Schmidt. Impact of CANKADO-based eHealth-support on quality of life in metastatic breast cancer patients treated with palbociclib and endocrine therapy - Precycle [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 OT3-14-02.

Abstract PD5-08: Tumor immune-cell activity assessed by RNAseq is an independent predictor of therapy response and prognosis after neoadjuvant chemotherapy in HER2 negative breast cancer patients - An analysis of the GeparSepto trial

Background: Tumor immune markers such as tumor infiltrating lymphocytes (TILs) or expression-based profiles have been correlated with both response to neoadjuvant chemotherapy and prognosis in early breast cancer (BC) patients. Some chemotherapies, such as paclitaxel, lead to the development of TILs and in some cases, suppression of regulatory T-cells. Therefore, assessment of the tumor microenvironment (TME) could provide important information for clinical decision-making. The aim of this study was to test if RNAseq-based TME classification of BC tumors is predictive of pathological complete Response (pCR) and prognosis in the neoadjuvant GeparSepto (G7) trial (NCT01583426). Methods: We performed a retrospective-prospective analysis of a subset of 810 subjects of the total of 1207 patients of the G7 trial. In G7 HER2-negative early high-risk BC patients were studied to determine if nab-paclitaxel is superior to solvent-based paclitaxel. In addition to the taxane paclitaxel, both treatment arms received epirubicin plus cyclophosphamide before surgery. For this analysis, a subset of 279 HER2 negative patients with sufficient quality of pretherapeutic core biopsies to perform whole-transcriptome RNAseq (~200x106 reads per tumor) was used. Based on RNAseq data, immune activity classification was provided by ImmunityBio (Culver City, CA) by comparison of expression of 23 immune-cell-specific gene signatures as described by Bindea et al. (Immunity, 2013) to those from a reference population of 1467 similarly-profiled unselected tumor samples from a large tumor database (NantOmics, Culver City, CA). Unsupervised hierarchical clustering of inferred immune activities revealed 3 distinct groups termed “hot”, “warm”, and “cold” clusters. Logistic regression analysis based on age, trial arm, tumor size, nodal status, Ki-67, hormone-receptor (HR) status and immune activity cluster (hot/warm vs. cold) as independent variables was performed to predict pCR (ypT0/ypN0). Cox regression analysis with the same covariates was also performed to predict disease-free survival (DFS) and overall survival (OS). Results: Of the 279 patients, 67 had a pCR (24%). The analyzed subset was similar to the main HER2 negative population (pCR-rate: 22%). Patients with a “hot/warm” or “cold” immune activity assessment had a pCR in 30% and 13% of the cases, respectively. The odds-ratio of the multivariate logistic regression analysis was 2.17 (95% CI: 1.00-4.71, p=0.0512). With regard to DFS and OS, T follicular helper cell B-cell, and T-cell signatures seemed to play a prominent role, and the hazard ratios (also “hot/warm” vs. “cold”) for the multivariate analyses were 0.38 (95% CI: 0.21-0.66; p=0.0007) and 0.34 (95%CI: 0.16-0.72, p= 0.0045), respectively. Within the 23 individual immune-cell-specific gene signatures, CD56dimNatural Killer (NK), type 1 helper T-cells, and CD8+ T-cell signatures seemed to be closely associated with achievement of a pCR. RNAseq-based deconvolution of immune-cell activity was corroborated by IHC-based TIL scoring. Immune-hot/warm patients had more intratumoral lymphocytes compared to cold tumors (mean: 11.6% vs. 4.9%, p&lt;0.0001). Specifically, adaptive immunity gene signatures (i.e. CD8+ T-cell signature, CD56dim NK, and Th1) were moderately correlated with the percentage of TILs (rho correlation coefficients from 0.42 to 0.53). Conclusion: TME profiling by RNAseq may be an independent biomarker useful for predicting response to and prognosis after neoadjuvant chemotherapy including taxanes and anthracyclines in early HER2 negative high-risk BC. These results indicate that the further development of this biomarker could be of direct clinical importance.

Citation Format: Peter A Fasching, Carsten Denkert, Stephen Benz, Karsten E Weber, Christopher Szeto, Jan Budczies, Andreas Schneeweiss, Elmar Stickeler, Sabine Schmatloch, Christian Jackisch, Thomas Karn, Hans Peter Sinn, Mathias Warm, Marion van Mackelenbergh, Sharooz Rabizadeh, Christian Schem, Ernst Heinmöller, Volkmar Müller, Frederik Marmé, Patrick Soon-Shiong, Valentina Nekljudova, Michael Untch, Sibylle Loibl. Tumor immune-cell activity assessed by RNAseq is an independent predictor of therapy response and prognosis after neoadjuvant chemotherapy in HER2 negative breast cancer patients - An analysis of the GeparSepto trial [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 PD5-08.

A Small Hypoxia Signature Predicted pCR Response to Bevacizumab in the Neoadjuvant GeparQuinto Breast Cancer Trial

PURPOSE

In breast cancer, bevacizumab increased pCR rate but not long-term survival and no predictive markers are available to identify patients with long-term benefit from the drug.

EXPERIMENTAL DESIGN

We profiled 289 pretherapeutic formalin-fixed, paraffin-embedded (FFPE) biopsies of HER2-negative patients from the GeparQuinto trial of neoadjuvant chemotherapy ± bevacizumab by exome-capture RNA-sequencing (RNA-seq). In a prospectively planned study, we tested molecular signatures for response prediction. IHC validation was performed using tissue microarrays.

RESULTS

We found strong agreement of molecular and pathologic parameters as hormone receptors, grading, and lymphocyte infiltration in 221 high-quality samples. Response rates (49.3% pCR overall) were higher in basal-like (68.9%) and HER2-enriched (45.5%) than in luminal B (35.7%), luminal A (17.9%), and normal-like (20.0%) subtypes. T-cell (OR = 1.60; 95% confidence interval, 1.21-2.12; P = 0.001), proliferation (OR = 2.88; 95% CI, 2.00-4.15; P < 0.001), and hypoxia signatures (OR = 1.92; 95% CI, 1.41-2.60; P < 0.001) significantly predicted pCR in univariate analysis. In a prespecified multivariate logistic regression, a small hypoxia signature predicted pCR (OR = 2.40; 95% CI, 1.28-4.51; P = 0.006) with a significant interaction with bevacizumab treatment (P = 0.020). IHC validation using NDRG1 as marker revealed highly heterogenous expression within tissue leading to profound loss of sensitivity in TMA analysis, still a significant predictive value for pCR was detected (P = 0.025).

CONCLUSIONS

Exome-capture RNA-seq characterizes small FFPE core biopsies by reliably detecting factors as for example ER status, grade, and tumor-infiltrating lymphocytes levels. Beside molecular subtypes and immune signatures, a small hypoxia signature predicted pCR to bevacizumab, which could be validated by IHC. The signature can have important applications for bevacizumab treatment in different cancer types and might also have a role for novel combination therapies of bevacizumab with immune checkpoint inhibition.

Human leucocyte antigen class I in hormone receptor-positive, HER2-negative breast cancer: association with response and survival after neoadjuvant chemotherapy

Background

Clinical application of cancer immunotherapy requires a better understanding of tumor immunogenicity and the tumor microenvironment. HLA class I molecules present antigens to CD8⁺ cytotoxic cells. Their loss or downregulation is frequently found in tumors resulting in reduced T cell responses and worse prognosis.

Methods

We evaluated HLA class I heavy chain expression by immunohistochemistry in 863 biopsies (GeparTrio trial). Patients received neoadjuvant chemotherapy and adjuvant endocrine treatment if tumors were hormone receptor-positive (HR+). In parallel, the expression of HLA-A was analyzed using a microarray cohort of 320 breast cancer patients from the MD Anderson Cancer Center. We evaluated its association with clinical outcome, tumor-infiltrating lymphocytes (TILs), and immune cell metagenes.

Results

In HR+/HER2− breast cancer, HLA class I heavy chain expression was associated with increased TILs and better response to chemotherapy (7% vs. 14% pCR rate, P = 0.029), but worse disease-free survival (hazard ratio (HR) 1.6 (1.1–2.4); P = 0.024). The effect was significant in a multivariate model adjusted for clinical and pathological variables (HR 1.7 (1.1–2.6); P = 0.016) and was confirmed by analysis of HLA-A in a microarray cohort. HLA-A was correlated to most immune cell metagenes. There was no association with response or survival in triple-negative or HER2+ disease.

Conclusions

The study confirms the negative prognostic role of lymphocytes in HR+ breast cancer and points at a complex interaction between chemotherapy, endocrine treatment, and tumor immunogenicity. The results point at a subtype-specific and potentially treatment-specific role of tumor-immunological processes in breast cancer with different implications in triple-negative and hormone receptor-positive disease.

Survival analysis of carboplatin added to an anthracycline/taxane-based neoadjuvant chemotherapy and HRD score as predictor of response-final results from GeparSixto

Background

In the neoadjuvant GeparSixto study, adding carboplatin to taxane- and anthracycline-based chemotherapy improved pathological complete response (pCR) rates in patients with triple-negative breast cancer (TNBC). Here, we present survival data and the potential prognostic and predictive role of homologous recombination deficiency (HRD).

Patients and methods

Patients were randomized to paclitaxel plus nonpegylated liposomal doxorubicin (Myocet®) (PM) or PM plus carboplatin (PMCb). The secondary study end points disease-free survival (DFS) and overall survival (OS) were analyzed. Median follow-up was 47.3 months. HRD was among the exploratory analyses in GeparSixto and was successfully measured in formalin-fixed, paraffin-embedded tumor samples of 193/315 (61.3%) participants with TNBC. Homologous recombination (HR) deficiency was defined as HRD score ≥42 and/or presence of tumor BRCA mutations (tmBRCA).

Results

A significantly better DFS (hazard ratio 0.56, 95% CI 0.34-0.93; P = 0.022) was observed in patients with TNBC when treated with PMCb. The improvement of OS with PMCb was not statistically significant. Additional carboplatin did not improve DFS or OS in patients with HER2-positive tumors. HR deficiency was detected in 136 (70.5%) of 193 triple-negative tumors, of which 82 (60.3%) showed high HRD score without tmBRCA. HR deficiency independently predicted pCR (ypT0 ypN0) [odds ratio (OR) 2.60, 95% CI 1.26-5.37, P = 0.008]. Adding carboplatin to PM significantly increased the pCR rate from 33.9% to 63.5% in HR deficient tumors (P = 0.001), but only marginally in HR nondeficient tumors (from 20.0% to 29.6%, P = 0.540; test for interaction P = 0.327). pCR rates with carboplatin were also higher (63.2%) than without carboplatin (31.7%; OR 3.69, 1.46-9.37, P = 0.005) in patients with high HRD score but no tmBRCA. DFS rates were improved with addition of carboplatin, both in HR nondeficient (hazard ratio 0.44, 0.17-1.17, P = 0.086) and HR deficient tumors (hazard ratio 0.49, 0.23-1.04, P = 0.059).

Conclusions

The addition of carboplatin to neoadjuvant PM improved DFS significantly in TNBC. Long-term survival analyses support the neoadjuvant use of carboplatin in TNBC. HR deficiency in TNBC and HRD score in non-tmBRCA TNBC are predictors of response. HRD does not predict for carboplatin benefit.

NAB-Paclitaxel Improves Disease-Free Survival in Early Breast Cancer: GBG 69–GeparSepto

PURPOSE

The GeparSepto trial demonstrated that weekly nanoparticle albumin-bound (NAB)–paclitaxel significantly improves the pathologic complete remission rate compared with weekly solvent-based (sb) paclitaxel followed by epirubicin plus cyclophosphamide as neoadjuvant treatment in patients with primary breast cancer (BC). Here, we report data on long-term outcomes.

METHODS

Patients with histologically confirmed primary BC were randomly assigned in a 1:1 ratio to 12 times weekly NAB-paclitaxel 150 mg/m2 (after study amendment, 125 mg/m2) or weekly sb-paclitaxel 80 mg/m2 followed in both arms by four times epirubicin 90 mg/m2 plus cyclophosphamide 600 mg/m2 every 3 weeks. Patients with human epidermal growth factor receptor 2 (HER2)-positive BC received dual antibody treatment with trastuzumab (8 mg/kg loading dose followed by 6 mg/kg every 3 weeks) and pertuzumab (840 mg loading dose followed by 420 mg every 3 weeks) concurrently to chemotherapy and continued for 1 year.

RESULTS

A total of 1,206 patients started treatment, 606 with NAB-paclitaxel and 600 with sb-paclitaxel. After a median follow-up of 49.6 months (range, 0.5 to 64.0 months), 243 invasive disease–free survival (iDFS) events were reported (143 in the sb-paclitaxel and 100 in the NAB-paclitaxel arm). At 4 years, overall patients treated with NAB-paclitaxel had a significantly better iDFS compared with sb-paclitaxel (84.0% v 76.3%; hazard ratio, 0.66; 95% CI, 0.51 to 0.86; P = .002), whereas overall survival did not significantly differ between the two treatment arms (89.7% v 87.2%, respectively; hazard ratio, 0.82; 95% CI, 0.59 to 1.16; P = .260). Long-term follow-up of the treatment-related peripheral sensory neuropathy (PSN) showed a significant decrease of the median time to resolve PSN after NAB-paclitaxel 125 mg/m2 compared with NAB-paclitaxel 150 mg/m2.

CONCLUSION

The significantly higher pathologic complete response rate with NAB-paclitaxel translated into a significantly improved iDFS in patients with early BC as compared with sb-paclitaxel. PSN improved much faster under NAB-paclitaxel 125 mg/m2 compared with NAB-paclitaxel 150 mg/m2.

Clinical Relevance of Collagen Protein Degradation Markers C3M and C4M in the Serum of Breast Cancer Patients Treated with Neoadjuvant Therapy in the GeparQuinto Trial

Background: Remodeling of extracellular matrix through collagen degradation is a crucial step in the metastatic cascade. The aim of this study was to evaluate the potential clinical relevance of the serum collagen degradation markers (CDM) C3M and C4M during neoadjuvant chemotherapy for breast cancer. Methods: Patients from the GeparQuinto phase 3 trial with untreated HER2-positive operable or locally advanced breast cancer were enrolled between 7 November 2007, and 9 July 2010, and randomly assigned to receive neoadjuvant treatment with EC/docetaxel with either trastuzumab or lapatinib. Blood samples were collected at baseline, after four cycles of chemotherapy and at surgery. Cutoff values were determined using validated cutoff finder software (C3M: Low ≤9.00 ng/mL, high >9.00 ng/mL, C4M: Low ≤40.91 ng/mL, high >40.91 ng/mL). Results: 157 patients were included in this analysis. At baseline, 11.7% and 14.8% of patients had high C3M and C4M serum levels, respectively. No correlation was observed between CDM and classical clinical-pathological factors. Patients with high levels of CDM were significantly more likely to achieve a pathological complete response (pCR, defined as ypT0 ypN0) than patients with low levels (C3M: 66.7% vs. 25.7%, p = 0.002; C4M: 52.7% vs. 26.6%, p = 0.031). Median levels of both markers were lower at the time of surgery than at baseline. In the multivariate analysis including clinical-pathological factors and C3M levels at baseline and changes in C3M levels between baseline and after four cycles of therapy, only C3M levels at baseline (p = 0.035, OR 4.469, 95%-CI 1.115–17.919) independently predicted pCR. In a similar model including clinical-pathological factors and C4M, only C4M levels at baseline (p = 0.028, OR 6.203, 95%-CI 1.220–31.546) and tumor size (p = 0.035, OR 4.900, 95%-CI 1.122–21.393) were independent predictors of pCR. High C3M levels at baseline did not correlate with survival in the entire cohort but were associated with worse disease-free survival (DFS; p = 0.029, 5-year DFS 40.0% vs. 74.9%) and overall survival (OS; p = 0.020, 5-year OS 60.0% vs. 88.3%) in the subgroup of patients randomized to lapatinib. In the trastuzumab arm, C3M did not correlate with survival. In the entire patient cohort, high levels of C4M at baseline were significantly associated with shorter DFS (p = 0.001, 5-year DFS 53.1% vs. 81.6%) but not with OS. When treatment arms were considered separately, the association with DFS was still significant (p = 0.014, 5-year DFS 44.4% vs. 77.0% in the lapatinib arm; p = 0.023, 5-year DFS 62.5% vs. 86.2% in the trastuzumab arm). Conclusions: Collagen degradation markers are associated with response to neoadjuvant therapy and seem to play a role in breast cancer.