Intense dose-dense epirubicin, paclitaxel, cyclophosphamide versus weekly paclitaxel, liposomal doxorubicin (plus carboplatin in triple-negative breast cancer) for neoadjuvant treatment of high-risk early breast cancer (GeparOcto-GBG 84): A randomised phase III trial

Background: GeparOcto compared efficacy and safety of two chemotherapy regimens in high-risk early breast cancer (BC): sequential treatment with intense dose-dense epirubicin, paclitaxel, and cyclophosphamide (iddEPC) and weekly treatment with paclitaxel plus non-pegylated liposomal doxorubicin (M, Myocet (R)) with additional carboplatin (PM(Cb)) in triple-negative BC (TNBC). Patients and methods: Patients with cT1c-cT4a-d and centrally assessed human epidermal growth factor receptor (HER) 2-positive BC or TNBC were eligible, irrespective of nodal status, luminal B-like tumours only if pN+. Patients were randomised (stratified by BC subtype, Ki67, lymphocyte-predominant BC) to receive 18 weeks of E (150 mg/m(2)) followed by P (225 mg/m(2)) followed by C (2000 mg/m(2)), each q2w for 3 cycles or weekly P (80 mg/m(2)) plus M (20 mg/m(2)) plus, in TNBC, Cb (area under curve (AUC) 1.5). HER2-positive BC patients additionally received trastuzumab (6 [loading dose 8]mg/kg q3w) and pertuzumab (420 [840]mg q3w) with all P and C cycles. Primary end-point was pathological complete response (pCR, ypT0/is ypN0), secondary end-points included other pCR definitions, pCR in stratified subpopulations, tolerability and compliance. This trial is registered with ClinicalTrials.gov number NCT02125344. Results: 945/961 randomised patients started treatment. The median age was 48 years; 7.6% had cT3-4, 46% cN+, 66% G3, 40% HER2-positive, 43% TNBC. pCR rate with iddEPC was 48.3%, with PM(Cb) 48.0%, respectively (PM(Cb) versus iddEPC odds ratio 0.99; 95% confidence interval 0.77-1.28, P = 0.979) with no significant differences observed in TNBC, HER2-positive, luminal B-like subtypes. 16.4% with iddEPC and 34.1% with PM(Cb) discontinued treatment (P < 0.001), mainly due to adverse events; two patients on PM(Cb) died. Conclusions: In high-risk early BC there is no difference in pCR rates following neoadjuvant treatment with iddEPC or weekly PM(Cb), respectively. iddEPC is one of the effective dose-dense regimens feasible in daily practice. (C) 2018 Elsevier Ltd. All rights reserved

Germline BRCA1/2 mutations and severe haematological toxicities in patients with breast cancer treated with neoadjuvant chemotherapy

Background: BRCA1 and BRCA2 play a central role in DNA repair. Therefore, patients harbouring germline (g) BRCA1/2 mutations (m) treated with chemotherapy might be at higher risk of haematological toxicities. Methods: Patients from German Breast Group (GBG) and Arbeitsgemeinschaft Gynakologische Onkologie-breast group studies with early triple-negative breast cancer (TNBC) and known gBRCA1/2m status treated with anthracycline-taxane-based neoadjuvant chemotherapy were analysed. Primary objective was the rate of neutropenia grade (G)III-IV in cycle 1 (C1). Secondary objectives included effects on overall and other haematological toxicities GIII-IV in C1, cumulative haematological toxicity across all cycles, relative total dose intensity, and granulocyte-colony stimulating factor prophylaxis. Haematological toxicities under taxanes, carboplatin, and cyclophosphamide were explored. Results: Two hundred nine of 1171 (17.8%) evaluated patients had gBRCA1/2m. In C1, 37.4% gBRCA1/2m versus 35.7% wild-type patients had neutropenia GIII-IV (P = 0.683). For C1, gBRCA1/2m predicted neither for neutropenia GIII-IV (odds ratio [OR]: 1.26, 95% confidence intervals [CI]: 0.87-1.82, P = 0.226) nor for other haematological toxicities GIII-IV (OR: 0.91, 95% CI: 0.64-1.31, P = 0.625) in multivariable regression models. Analyses of cumulative toxicities across all cycles yielded similar results except thrombocytopaenia GIII-IV, which was increased in gBRCA1m patients. In patients treated with taxanes, the rate of haematological toxicities GIII-IV was higher in gBRCA1/2m compared with wild-type (59.5% versus 43.1%; p < 0.001). No difference was seen under cyclophosphamide or platinum-containing chemotherapies. Conclusions: gBRCA1/2m was not associated with higher risk of overall severe haematological toxicities in the first cycle or cumulatively across all cycles under standard chemotherapy for TNBC. Under taxane, patients with gBRCA1/2m might have a higher risk of haematological toxicities GIII-IV, requiring further research. (C) 2020 Elsevier Ltd. All rights reserved

Association of Germline Variant Status With Therapy Response in High-risk Early-Stage Breast Cancer A Secondary Analysis of the GeparOcto Randomized Clinical Trial

Importance The GeparOcto randomized clinical trial compared the efficacy of 2 neoadjuvant breast cancer (BC) treatment regimens: sequential intense dose-dense epirubicin, paclitaxel, and cyclophosphamide (iddEPC) vs weekly paclitaxel and nonpegylated liposomal doxorubicin (PM) in patients with different biological BC subtypes. Patients with triple-negative BC (TNBC) randomized to the PM arm received additional carboplatin (PMCb). Overall, no difference in pathologic complete response (pCR) rates was observed between study arms. It remained elusive whether the germline variant status of BRCA1/2 and further BC predisposition genes are associated with treatment outcome. Objective To determine treatment outcome for BC according to germline variant status. Design, Setting, and Participants This retrospective biomarker study is a secondary analysis of the GeparOcto multicenter prospective randomized clinical trial conducted between December 2014 and June 2016. Genetic analyses assessing for variants in BRCA1/2 and 16 other BC predisposition genes in 914 of 945 women were performed at the Center for Familial Breast and Ovarian Cancer, Cologne, Germany, from August 2017 through December 2018. Main Outcomes and Measures Proportion of patients who achieved pCR (ypT0/is ypN0 definition) after neoadjuvant treatment according to germline variant status. Results In the study sample of 914 women with different BC subtypes with a mean (range) age at BC diagnosis of 48 (21-76) years, overall higher pCR rates were observed in patients with BRCA1/2 variants than in patients without (60.4% vs 46.7%; odds ratio [OR], 1.74; 95% CI, 1.13-2.68; P = .01); variants in non-BRCA1/2 BC predisposition genes were not associated with therapy response. Patients with TNBC with BRCA1/2 variants achieved highest pCR rates. In the TNBC subgroup, a positive BRCA1/2 variant status was associated with therapy response in both the PMCb arm (74.3% vs 47.0% without BRCA1/2 variant; OR, 3.26; 95% CI, 1.44-7.39; P = .005) and the iddEPC arm (64.7% vs 45.0%; OR, 2.24; 95% CI, 1.04-4.84; P = .04). A positive BRCA1/2 variant status was also associated with elevated pCR rates in patients with ERBB2-negative, hormone receptor-positive BC (31.8% vs 11.9%; OR, 3.44; 95% CI, 1.22-9.72; P = .02). Conclusions and Relevance Effective chemotherapy for BRCA1/2-mutated TNBC is commonly suggested to be platinum based. With a pCR rate of 64.7%, iddEPC may also be effective in these patients, though further prospective studies are needed. The elevated pCR rate in BRCA1/2-mutated ERBB2-negative, hormone receptor-positive BC suggests that germline BRCA1/2 testing should be considered prior to treatment start. Question Is germline variant status of BRCA1/2 and non-BRCA1/2 breast cancer predisposition genes associated with higher response rates in patients enrolled in the GeparOcto trial? Findings In this secondary analysis of 914 patients included in a randomized clinical trial, women with triple-negative breast cancer with BRCA1/2 variants benefited most from both treatment regimens (paclitaxel and nonpegylated liposomal doxorubicin plus carboplatin, 74.3%; epirubicin, paclitaxel, and cyclophosphamide, 64.7%). A positive BRCA1/2 variant status also was associated with higher response rates in ERBB2-negative, hormone receptor-positive breast cancer. Meaning Effective chemotherapy for BRCA1/2-mutated triple-negative breast cancer is commonly suggested to be platinum based; sequential intense dose-dense epirubicin, paclitaxel, and cyclophosphamide appears to also be effective in these patients, though with a lower point estimate. Patients with ERBB2-negative, hormone receptor-positive breast cancer may benefit from BRCA1/2 testing prior to treatment. This secondary analysis of a randomized clinical trial assesses treatment outcomes in women with different biological types of breast cancer according to germline variant status of BRCA1/2 and non-BRCA1/2 breast cancer predisposition genes

Clinical and molecular characteristics of HER2-low-positive breast cancer: pooled analysis of individual patient data from four prospective, neoadjuvant clinical trials

Background The development of anti-HER2 antibody-drug conjugates opens new therapeutic options for patients with breast cancer, including patients with low expression of HER2. To characterise this new breast cancer subtype, we have compared the clinical and molecular characteristics of HER2-low-positive and HER2-zero breast cancer, including response to neoadjuvant chemotherapy and prognosis. Methods In this pooled analysis of individual patient data, we evaluated a cohort of 2310 patients with HER2non-amplified primary breast cancer that were treated with neoadjuvant combination chemotherapy in four prospective neoadjuvant clinical trials (GeparSepto, NCT01583426; GeparOcto, NCT02125344; GeparX, NCT02682693; Gain-2 neoadjuvant, NCT01690702) between July 30, 2012, and March 20, 2019. Central HER2 testing was done prospectively before random assignment of participants in all trials. HER2-low-positive status was defined as immunohistochemistry (IHC) 1+ or IHC2+/in-situ hybridisation negative and HER2-zero was defined as IHC0, based on the American Society of Clinical Oncology/College of American Pathologists guidelines. Disease-free survival and overall survival data were available for 1694 patients (from all trials except GeparX) with a median followup of 46.6 months (IQR 35.0-52.3). Bivariable and multivariable logistic regression models and Cox-proportional hazards models were performed based on a predefined statistical analysis plan for analysis of the endpoints pathological complete response, disease-free survival, and overall survival. Findings A total of 1098 (47.5%) of 2310 tumours were HER2-low-positive and 1212 (52.5%) were HER2-zero. 703 (64.0%) of 1098 patients with HER2-low-positive tumours were hormone receptor positive, compared with 445 (36.7%) of 1212 patients with HER2-zero tumours (p<0.0001). HER2-low-positive tumours had a significantly lower pathological complete response rate than HER2-zero tumours (321 [29.2%] of 1098 vs 473 [39.0%] of 1212, p=0.0002). Pathological complete response was also significantly lower in HER2-low-positive tumours versus HER2-zero tumours in the hormone receptor-positive subgroup (123 [17.5%] of 703 vs 105 [23.6%] of 445, p=0.024), but not in the hormone receptor-negative subgroup (198 [50.1%] of 395 vs 368 [48.0%] of 767, p=0.21). Patients with HER2-low-positive tumours had significantly longer survival than did patients with HER2-zero tumours (3-year disease-free survival: 83.4% [95% CI 80.5-85.9] vs 76.1% [72.9-79.0]; stratified log-rank test p=0.0084; 3-year overall survival: 91.6% [84.9-93.4] vs 85.8% [83.0-88.1]; stratified log-rank test p=0.0016). Survival differences were also seen in patients with hormone receptor-negative tumours (3-year disease free survival: 84.5% [95% CI 79.5-88.3] vs 74.4% [70.2-78.0]; stratified log-rank test p=0.0076; 3-year overall survival: 90.2% [86.0-93.2] vs 84.3% [80.7-87.3], stratified log-rank test p=0.016), but not in patients with hormone receptor-positive tumours (3-year disease-free survival 82.8% [79.1-85.9] vs 79.3% [73.9-83.7]; stratified log-rank test p=0.39; 3-year overall survival 92.3% [89.6-94.4] vs 88.4% [83.8-91.8]; stratified log-rank test p=0.13). Interpretation Our results show that HER2-low-positive tumours can be identified as new subgroup of breast cancer by standardised IHC, distinct from HER2-zero tumours. HER2-low-positive tumours have a specific biology and show differences in response to therapy and prognosis, which is particularly relevant in therapy-resistant, hormone receptor-negative tumours. Our results provide a basis for a better understanding of the biology of breast cancer subtypes and the refinement of future diagnostic and therapeutic strategies. Funding German Cancer Aid (Deutsche Krebshilfe). Copyright (c) 2021 Elsevier Ltd. All rights reserved