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 HER2-non-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 follow-up 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).

A randomized phase II study to determine the efficacy and tolerability of two doses of eribulin plus lapatinib in trastuzumab-pretreated patients with HER-2-positive metastatic breast cancer (E-VITA).

The E-VITA study evaluated the efficacy and tolerability of two schedules of eribulin and lapatinib in patients with trastuzumab-pretreated HER-2-positive metastatic breast cancer. This multicenter, open-label phase II trial, randomly assigned patients with trastuzumab-pretreated HER-2-positive metastatic breast cancer to lapatinib 1000 mg daily with eribulin 1.23 mg/m (equivalent to 1.4 mg/m eribulin mesylate) days 1+8 every 21 days (split-dose arm) or eribulin 1.76 mg/m (equivalent to 2.0 mg/m eribulin mesylate) day 1 every 21 days (3-weekly arm). Time to progression and tolerability were defined as primary end points; no sample size calculation for formal comparison of efficacy data has been performed. Secondary end points included objective response rate, clinical benefit rate, and overall survival. Overall, 43 patients of a planned number of 80 patients were recruited. At a median follow-up of 28.7 months, the median time to progression was 8.1 months [95% confidence interval (CI): 4.8-9.4] in the split-dose arm and 6.5 months (95% CI: 4.6-13.4) in the 3-weekly arm. Objective response rate was 52.4% (95% CI: 31.0-73.7) in the split-dose arm and 45.0% (95% CI: 23.2-66.8) in the 3-weekly arm, and clinical benefit rate was 71.4% (95% CI: 52.1-90.8) and 75.0% (95% CI: 56.0-94.0), respectively. Overall survival was also similar in both arms. The most frequent grade 3-4 adverse events were neutropenia (58.5%) and leukopenia (39.0%). The combination of eribulin and lapatinib showed an acceptable safety profile with less toxicity observed in the eribulin 1.23 mg/m day 1+8 group. This might be an alternative regimen when other treatment options are exhausted. Therefore, further clinical studies are warranted.

Phase III study on efficacy of taxanes plus bevacizumab with or without capecitabine as first-line chemotherapy in metastatic breast cancer.

Taxanes (T) plus bevacizumab (B) and taxanes plus capecitabine (X) showed better progression-free survival (PFS) compared to taxanes alone. Since life-threatening or highly symptomatic situations require polychemotherapy in metastatic breast cancer (MBC), combination of taxanes, capecitabine plus bevacizumab appears reasonable. TABEA (NCT01200212), a prospectively randomized, open-label, phase III trial compares taxanes (paclitaxel 80 mg/m(2) i.v. d1,8,15 q22 or docetaxel 75 mg/m(2) i.v. d1 q22) plus bevacizumab (15 mg/kg i.v. d1 q22) with (TBX) or without capecitabine (TB, 1800 mg/m(2) daily d1-14 q22) as first-line therapy in MBC. Histologically confirmed HER2-negative, locally advanced or MBC patients with a chemotherapy indication and measurable or non-measurable target lesions (RECIST criteria) were included. Primary objective was PFS. Secondary objectives were response rate and duration, clinical benefit rate (complete response, partial response, stable disease ≥24 weeks), 3-year overall survival, PFS in patients ≥65 years, toxicity, and compliance. We assumed 10 and 13.3 months PFS for TB and TBX, respectively (HR = 0.75), requiring 432 patients and 386 events. Preplanned interim futility and safety analyses after 100 events in 202 patients showed no efficacy benefit and higher toxicity for TBX. Recruitment and therapy were stopped following advice from the IDMC. Final analysis revealed a HR 1.13 [95 %CI 0.806-1.59], P = 0.474, for PFS. Overall grade 3-4 adverse event (77.3 vs. 62.1 %, P = 0.014) and serious adverse event (40.0 vs. 30.2 %, P = 0.127) rates were higher for TBX after 26.1 months median follow-up, with six deaths for TBX versus 1 for TB. Adding capecitabine to TB cannot be recommended as first-line therapy in MBC.

Changes in serum levels of miR-21, miR-210, and miR-373 in HER2-positive breast cancer patients undergoing neoadjuvant therapy: a translational research project within the Geparquinto trial.

Trastuzumab and lapatinib are established treatments for patients with HER2 (human epidermal growth factor receptor 2)-positive breast cancer with different mechanisms of action. The focus of this study is to investigate, whether altered expression levels of potentially relevant microRNAs (miRs) in serum are associated with response to trastuzumab or lapatinib. Circulating miR-21, miR-210, and miR-373 were quantified with TaqMan MicroRNA assays in serum of 127 HER2-postive breast cancer patients before and after neoadjuvant therapy and in 19 healthy controls. Patients received chemotherapy combined with either trastuzumab or lapatinib within the prospectively randomized Geparquinto trial. The association between miR levels and pathological response (pCR) to therapy and type of therapy was examined. Serum levels of miR-21 (p = 5.04e-08, p = 1.43e-10), miR-210 (p = 0.00151, p = 1.6e-05), and miR-373 (p = 7.87e-06, p = 1.75e-07) were significantly higher in patients before and after chemotherapy than in healthy women. Concentrations of miR-21 (p = 5.73e-08), miR-210 (p = 0.000724), and miR-373 (p = 0.00209) increased further after chemotherapy. A significant association of higher serum levels of miR-373 with advanced clinical tumor stage could be detected (p < 0.002). An association of miR-21 levels before (p = 0.0091) and after (p = 0.037) chemotherapy with overall survival of the patients could be detected, independent of type of anti-HER2 therapy. No association of circulating miRs with pCR was found. Our findings demonstrate a specific influence of neoadjuvant therapy on the serum levels of miR-21, miR-210, and miR-373 in breast cancer patients together with a prognostic value of miR-21.

Anti-hormonal maintenance treatment with the CDK4/6 inhibitor ribociclib after 1st line chemotherapy in hormone receptor positive / HER2 negative metastatic breast cancer: A phase II trial (AMICA).

PURPOSE: This phase II study evaluated the impact of adding ribociclib to maintenance endocrine therapy (ET) treatment of physicians' choice following the first palliative chemotherapy in pre- and post-menopausal women with hormone receptor positive (HR+)/human epidermal growth factor 2 negative (HER2-) metastatic breast cancer (mBC). PATIENTS AND METHODS: The initial randomized study design was later amended into a single-arm study, and all subsequent patients received ribociclib and ET. The primary end point was locally assessed progression-free survival (PFS). Secondary end points included overall survival (OS), clinical benefit rate (CBR), safety, compliance, and quality of life (QoL). RESULTS: A total of 43 patients received ribociclib + ET and 10 patients received ET only. Median PFS was 12.4 months [95% CI 8.7-24.4] for patients who received ribociclib + ET and 4.75 months [95% CI 1.0-10.3] for those who received ET only. Median OS was not reached for patients who received ribociclib + ET, and 28 (65.1%) patients experienced clinical benefit [95% CI 49.1-79.0]. For patients who received ribociclib + ET, grade 3-4 hematological adverse events (AEs) occurred in 25 (58.1%) patients, and grade 3-4 non-hematological AEs occurred in 17 (39.5%) patients. During the study, 15 patients died - 14 of whom due to tumor-related reasons, and one patient due to pneumonia, which was not treatment-related. CONCLUSION: The results of the AMICA study show a promising efficacy and safety of maintenance treatment with ribociclib added to ET after at least stable disease following the first metastatic chemotherapy in patients with HR+/HER2-mBC. TRIAL REGISTRATION: Anti-hormonal Therapy With Ribociclib in HR-positive/HER2- Negative Metastatic Breast Cancer (AMICA), NCT03555877, https://clinicaltrials.gov/ct2/show/NCT03555877.

Adjuvant trastuzumab emtansine in HER2-positive breast cancer patients with HER2-negative residual invasive disease in KATHERINE.

Following chemotherapy and human epidermal growth factor 2 (HER2)-targeted neoadjuvant therapy for HER2-positive early breast cancer, residual invasive breast cancer at surgery may be HER2-negative on retesting in some patients. We evaluated outcomes with T-DM1 and trastuzumab in patients randomized in the phase III KATHERINE trial based on HER2-positive central testing of the pre-treatment core biopsy with HER2-negative central testing on their corresponding surgical specimen after neoadjuvant treatment. In the 70/845 (8.3%) patients with HER2-negative residual disease on retesting at surgery, there were 11 IDFS events in the 42 trastuzumab-treated patients (26.2%) and none in the 28 T-DM1-treated patients, suggesting that T-DM1 should not be withheld in this patient population.

Survival analysis of the randomised phase III GeparOcto trial comparing neoadjuvant chemotherapy of intense dose-dense epirubicin, paclitaxel, cyclophosphamide versus weekly paclitaxel, liposomal doxorubicin (plus carboplatin in triple-negative breast cancer) for patients with high-risk early breast cancer.

BACKGROUND: GeparOcto demonstrated that pathological complete response (pCR) of intense dose-dense epirubicin, paclitaxel and cyclophosphamide (iddEPC) was comparable to weekly paclitaxel/non-pegylated liposomal doxorubicin (plus carboplatin (PM(Cb) in triple-negative breast cancer [TNBC]) in high-risk early breast cancer (BC). Here, we report time-to-event secondary end-points. PATIENTS AND METHODS: Patients were randomised to receive 18 weeks of E (150 mg/m2) followed by P (225 mg/m2) followed by C (2000 mg/m2), each q2w or weekly P (80 mg/m2) plus M (20 mg/m2) plus, in TNBC, Cb (AUC 1.5). Patients with human epidermal growth factor receptor 2-positive (HER2+)BC received trastuzumab (6[loading dose 8]mg/kg q3w) and pertuzumab (420[840]mg q3w) with P and C cycles. RESULTS: 945 patients started treatment (iddEPC n = 470; PM(Cb) n = 475). After a median follow-up of 47.0 (range 1.6-61.5) months, 162 (75 in iddEPC; 87 in PM(Cb)) invasive disease-free survival (iDFS) events and 79 (41 in iddEPC; 38 in PM(Cb)) deaths were reported. No significant difference was observed in 4-year iDFS (81.9% iddEPC versus 79.7% PM(Cb), HR = 1.16 [95%CI 0.85-1.59], log-rank p = 0.334) or 4-year overall survival (OS) (90.3% iddEPC versus 90.6% PM(Cb), HR = 0.90 [95%CI 0.58-1.40], log-rank p = 0.637) overall and in HER2+ and TNBC subgroups. HR+/HER2- BC patients, however, had significantly better 4-year iDFS (77.9% iddEPC versus 62.5% PM, HR = 2.11 [95%CI 1.08-4.10], log-rank p = 0.025) and 4-year OS with iddEPC (94.7% iddEPC versus 80.1% PM, HR = 3.26 [95%CI 1.06-10.00], log-rank p = 0.029). CONCLUSION: While there was no difference in survival for the entire cohort, the HR+/HER2-subgroup significantly benefits from iddEPC. This supports the concept of an additional effect of NACT beyond pCR in patients with HR+/HER2- BC. CLINICALTRIALS. GOV IDENTIFIER: NCT02125344.

Pathological Response in the Breast and Axillary Lymph Nodes after Neoadjuvant Systemic Treatment in Patients with Initially Node-Positive Breast Cancer Correlates with Disease Free Survival: An Exploratory Analysis of the GeparOcto Trial.

BACKGROUND: The conversion of initially histologically confirmed axillary lymph node-positive (pN+) to ypN0 after neoadjuvant systemic treatment (NAST) is an important prognostic factor in breast cancer (BC) patients and may influence surgical de-escalation strategies. We aimed to determine pCR rates in lymph nodes (pCR-LN), the breast (pCR-B), and both (tpCR) in women who present with pN+ BC, to assess predictors for response and the impact of pCR-LN, pCR-B, and tpCR on invasive disease-free survival (iDFS). METHODS: Retrospective, exploratory analysis of 242 patients with pN+ at diagnosis from the multicentric, randomized GeparOcto trial. RESULTS: Of 242 patients with initially pN+ disease, 134 (55.4%) had a pCR-LN, and 109 (45.0%) a pCR-B. Of the 109 pCR-B patients, 9 (8.3%) patients had involved LN, and 100 (41.3%) patients had tpCR. Those with involved LN still had a bad prognosis. As expected, pCR-B and intrinsic subtypes (TNBC and HER2+) were identified as independent predictors of pCR-LN. pCR-LN (ypN0; hazard ratio 0.42; 95%, CI 0.23-0.75; p = 0.0028 for iDFS) was the strongest independent prognostic factor. CONCLUSIONS: In initially pN+ patients undergoing NAST, the conversion to ypN0 is of high prognostic value. Surgical axillary staging after NAST is still essential in these patients to offer tailored treatment.

Predicting Prognosis of Breast Cancer Patients with Brain Metastases in the BMBC Registry-Comparison of Three Different GPA Prognostic Scores.

Several scores have been developed in order to estimate the prognosis of patients with brain metastases (BM) by objective criteria. The aim of this analysis was to validate all three published graded-prognostic-assessment (GPA)-scores in a subcohort of 882 breast cancer (BC) patients with BM in the Brain Metastases in the German Breast Cancer (BMBC) registry. The median age at diagnosis of BM was 57 years. All in all, 22.3% of patients (n = 197) had triple-negative, 33.4% (n = 295) luminal A like, 25.1% (n = 221) luminal B/HER2-enriched like and 19.2% (n = 169) HER2 positive like BC. Age ≥60 years, evidence of extracranial metastases (ECM), higher number of BM, triple-negative subtype and low Karnofsky-Performance-Status (KPS) were all associated with worse overall survival (OS) in univariate analysis (p < 0.001 each). All three GPA-scores were associated with OS. The breast-GPA showed the highest probability of classifying patients with survival above 12 months in the best prognostic group (specificity 68.7% compared with 48.1% for the updated breast-GPA and 21.8% for the original GPA). Sensitivities for predicting 3 months survival were very low for all scores. In this analysis, all GPA-scores showed only moderate diagnostic accuracy in predicting the OS of BC patients with BM.

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 Gynäkologische 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.

Characteristics and Clinical Outcome of Breast Cancer Patients with Asymptomatic Brain Metastases.

Background: Brain metastases (BM) have become a major challenge in patients with metastatic breast cancer. Methods: The aim of this analysis was to characterize patients with asymptomatic BM (n = 580) in the overall cohort of 2589 patients with BM from our Brain Metastases in Breast Cancer Network Germany (BMBC) registry. Results: Compared to symptomatic patients, asymptomatic patients were slightly younger at diagnosis (median age: 55.5 vs. 57.0 years, p = 0.01), had a better performance status at diagnosis (Karnofsky index 80-100%: 68.4% vs. 57%, p < 0.001), a lower number of BM (>1 BM: 56% vs. 70%, p = 0.027), and a slightly smaller diameter of BM (median: 1.5 vs. 2.2 cm, p < 0.001). Asymptomatic patients were more likely to have extracranial metastases (86.7% vs. 81.5%, p = 0.003) but were less likely to have leptomeningeal metastasis (6.3% vs. 10.9%, p < 0.001). Asymptomatic patients underwent less intensive BM therapy but had a longer median overall survival (statistically significant for a cohort of HER2-positive patients) compared to symptomatic patients (10.4 vs. 6.9 months, p < 0.001). Conclusions: These analyses show a trend that asymptomatic patients have less severe metastatic brain disease and despite less intensive local BM therapy still have a better outcome (statistically significant for a cohort of HER2-positive patients) than patients who present with symptomatic BM, although a lead time bias of the earlier diagnosis cannot be ruled out. Our analysis is of clinical relevance in the context of potential trials examining the benefit of early detection and treatment of BM.

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.

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. Trial Registration: ClinicalTrials.gov Identifier: NCT02125344.

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®) 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/m2) followed by P (225 mg/m2) followed by C (2000 mg/m2), each q2w for 3 cycles or weekly P (80 mg/m2) plus M (20 mg/m2) 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.

Everolimus as treatment for breast cancer patients with bone metastases only: results of the phase II RADAR study.

PURPOSE: Everolimus has shown to stop formation and activity of osteoclasts. Breast cancer patients with bone metastases only are candidates for effective but low toxic treatment. PATIENTS AND METHODS: We evaluated everolimus in a double-blind, placebo-controlled, phase II, randomized discontinuation study in breast cancer patients with HER2 negative breast cancer patients with bone metastases only. After being stable on 8 weeks of everolimus 10 mg/day, patients were randomized to everolimus-continuation or placebo. Primary outcome was time (from randomization) to progression (TTP). Seventy-six patients would have had to be randomized to show a hazard ration (HR) of 0.5 for everolimus-continuation. RESULTS: Eighty-nine patients were enrolled in 4 years. Thirty-nine patients with SD after 8 weeks on everolimus were randomized to everolimus-continuation or placebo. TTP in patients with everolimus-continuation was 37.0 (95 % CI 16.7-40.3) versus 12.6 weeks (95 % CI 7.1-17.9) with placebo [HR 0.554 (95 % CI 0.282-1.09) p = 0.0818], adjusted for endocrine therapy [HR 0.464 (95 % CI 0.226-0.954) p = 0.037]. TTP in everolimus responders (n = 6) was 86 weeks. CONCLUSION: The RADAR study is mainly hypothesis generating. It suggests that everolimus has single-agent activity, and patients with bone metastases only may retrieve long-term benefit from everolimus if they do not progress within 8 weeks of treatment.