Neoadjuvant durvalumab improves survival in early triple-negative breast cancer independent of pathological complete response.

BACKGROUND: Addition of immune checkpoint inhibitors to neoadjuvant chemotherapy (NACT) is a promising strategy in early breast cancer, but the optimal duration of therapy is currently unknown. In the GeparNuevo (NCT02685059) trial, addition of durvalumab to NACT as previously reported led to a moderate increase in pathological complete response (pCR) rate by an absolute 9% (P = 0.287). PATIENTS AND METHODS: Patients with cT1b-cT4a-d triple-negative breast cancer (TNBC) received durvalumab 1.5 g or placebo every 4 weeks added to nab-paclitaxel 125 mg/m2 weekly for 12 weeks, followed by durvalumab/placebo every 4 weeks plus epirubicin/cyclophosphamide every 2 weeks followed by surgery. Durvalumab was not continued after surgery. The primary objective was pCR. Secondary endpoints included invasive disease-free survival (iDFS), distant disease-free survival (DDFS) and overall survival (OS). RESULTS: A total of 174 patients were randomised between June 2016 and October 2017. After a median follow-up of 43.7 months, 34 events had occurred. Despite a non-significant increase in the pCR rate, significant differences were observed for 3-year iDFS, DDFS and OS: iDFS was 85.6% with durvalumab versus 77.2% with placebo [hazard ratio (HR) 0.48, 95% confidence interval (CI) 0.24-0.97, stratified log-rank P = 0.036]; DDFS 91.7% versus 78.4% (HR 0.31, 95% CI 0.13-0.74, P = 0.005); OS 95.2% versus 83.5% (HR 0.24, 95% CI 0.08-0.72, P = 0.006). pCR patients had 3-year iDFS of 95.5% with durvalumab and 86.1% without (HR 0.22, 95% CI 0.05-1.06). In the non-pCR cohort 3-year iDFS was 76.3% versus 69.7% (HR 0.67, 95% CI 0.29-1.54). Multivariable analysis confirmed a durvalumab effect independent of the pCR effect. No new safety signals occurred. CONCLUSIONS: Durvalumab added to NACT in TNBC significantly improved survival despite a modest pCR increase and no adjuvant component of durvalumab. Additional studies are needed to clarify the optimal duration and sequence of checkpoint inhibitors in the treatment of early TNBC.

Outcome of breast cancer patients with low hormone receptor positivity: analysis of a 15-year population-based cohort.

BACKGROUND: Guideline recommendations for the treatment of breast cancer with low hormone receptor (HR) expression (1%-9%) are ambiguous and several studies showed more similarities with HR-negative tumors than with HR strongly positive tumors (≥10%). We used a population-based 15-year cohort to compare patient characteristics and outcome of HR low positive tumors with HR-negative and HR strongly positive tumors, respectively. PATIENTS AND METHODS: A total of 38  560 women diagnosed with early invasive breast cancer between 2004 and 2018 within the scope of the Munich Cancer Registry with 4.9 million inhabitants were included. Descriptive analyses of prognostic factors, treatment, and outcome analyses using the Kaplan-Meier method; cumulative incidence in consideration of competing risks; and multivariate analyses (Cox regression and Fine-Gray model) were conducted. Endpoints were time to local recurrence (TTLR), time to lymph node recurrence (TTLNR), time to metastasis (TTM), overall survival (OS), and relative survival (RS). RESULTS: A total of 861 patients (2%) had HR low positive, 4862 (13%) HR-negative, and 32  837 (85%) HR strongly positive tumors. Within the HER2-negative cohort (n = 33  366), survival of HR low positive tumors was significantly worse than that of HR strongly positive tumors [OS hazard ratio 0.66 (95% confidence interval 0.55-0.78)], whereas between HR low positive and HR-negative tumors no significant survival difference could be detected [OS hazard ratio 0.93 (95% confidence interval 0.78-1.11)]. TTLR, TTLNR, and TTM showed similar results. By contrast, within the HER2-positive cohort (n = 5194), no statistically significant differences between the three HR groups could be detected in multivariate analyses. CONCLUSION: Current definitions for HR positivity and its clinical relevance should be reconsidered. Patients with HR low positive/HER2-negative tumors could be regarded and treated similar to patients with triple-negative tumors.

Association of RAD51 with homologous recombination deficiency (HRD) and clinical outcomes in untreated triple-negative breast cancer (TNBC): analysis of the GeparSixto randomized clinical trial.

BACKGROUND: Current genetic and genomic tests measuring homologous recombination deficiency (HRD) show limited predictive value. This study compares the performance of an immunohistology-based RAD51 test with genetic/genomic tests to identify patients with HRD primary triple-negative breast cancer (TNBC) and evaluates its accuracy to select patients sensitive to platinum-based neoadjuvant chemotherapy (NACT). PATIENTS AND METHODS: This is a retrospective, blinded, biomarker analysis from the GeparSixto randomized clinical trial. TNBC patients received neoadjuvant paclitaxel plus Myocet®-nonpegylated liposomal doxorubicin (PM) or PM plus carboplatin (PMCb), both arms including bevacizumab. Formalin-fixed paraffin-embedded (FFPE) tumor samples were laid on tissue microarrays. RAD51, BRCA1 and γH2AX were quantified using an immunofluorescence assay. The predictive value of RAD51 was assessed by regression models. Concordance analyses were carried out between RAD51 score and tumor BRCA (tBRCA) status or genomic HRD score (Myriad myChoice®). Associations with pathological complete response (pCR) and survival were studied. Functional HRD was predefined as a RAD51 score ≤10% (RAD51-low). RESULTS: Functional HRD by RAD51-low was evidenced in 81/133 tumors (61%). RAD51 identified 93% tBRCA-mutated tumors and 45% non-tBRCA mutant cases as functional HRD. The concordance between RAD51 and genomic HRD was 87% [95% confidence interval (CI) 79% to 93%]. In patients with RAD51-high tumors, pCR was similar between treatment arms [PMCb 31% versus PM 39%, odds ratio (OR) 0.71, 0.23-2.24, P = 0.56]. Patients with RAD51-low tumors benefited from PMCb (pCR 66% versus 33%, OR 3.96, 1.56-10.05, P = 0.004; interaction test P = 0.02). This benefit maintained statistical significance in the multivariate analysis. Carboplatin addition showed similar disease-free survival in the RAD51-high [hazard ratio (HR) 0.40, log-rank P = 0.11] and RAD51-low (0.45, P = 0.11) groups. CONCLUSIONS: The RAD51 test identifies tumors with functional HRD and is highly concordant with tBRCA mutation and genomic HRD. RAD51 independently predicts clinical benefit from adding Cb to NACT in TNBC. Our results support further development to incorporate RAD51 testing in clinical decision-making.

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.

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.

Axillary staging for breast cancer during pregnancy: feasibility and safety of sentinel lymph node biopsy.

BACKGROUND: Safety of sentinel lymph node (SLN) biopsy for breast cancer during pregnancy is insufficiently explored. We investigated efficacy and local recurrence rate in a large series of pregnant patients. PATIENTS AND METHODS: Women diagnosed with breast cancer who underwent SLN biopsy during pregnancy were identified from the International Network on Cancer, Infertility and Pregnancy, the German Breast Group, and the Cancer and Pregnancy Registry. Chart review was performed to record technique and outcome of SLN biopsy, locoregional and distant recurrence, and survival. RESULTS: We identified 145 women with clinically N0 disease who underwent SLN during pregnancy. The SLN detection techniques were as follows: 99mTc-labeled albumin nanocolloid only (n = 96; 66.2%), blue dye only (n = 14; 9.7%), combined technique (n = 15; 10.3%), or unknown (n = 20; 13.8%). Mapping was unsuccessful in one patient (0.7%) and she underwent an axillary lymph node dissection (ALND). Mean number of SLNs was 3.2 (interquartile range 1-3; missing n = 15). Positive SLNs were found in 43 (29.7%) patients and 34 subsequently underwent ALND. After a median follow-up of 48 months (range 1-177), 123 (84.8%) patients were alive and free of disease. Eleven patients experienced a locoregional relapse, including 1 isolated ipsilateral axillary recurrence (0.7%). Eleven (7.6%) patients developed distant metastases, of whom 9 (6.2%) died of breast cancer. No neonatal adverse events related to SLN procedure during pregnancy were reported. CONCLUSIONS: SLN biopsy during pregnancy has a comparably low axillary recurrence rate as in nonpregnant women. Therefore, this method can be considered during pregnancy instead of standard ALND for early-stage, clinically node-negative breast cancer.

German Adjuvant Intergroup Node-positive Study (GAIN): a phase III trial comparing two dose-dense regimens (iddEPC versus ddEC-PwX) in high-risk early breast cancer patients.

BACKGROUND: Dose-dense (dd) regimens are one of the preferred options for the adjuvant treatment of breast cancer patients with intermediate to high risk. The German Adjuvant Intergroup Node-positive trial aimed at optimizing intense dd (idd) strategies by evaluating drug combinations and the addition of capecitabine. PATIENTS AND METHODS: Women (aged 18 years and biologically <65 years) with histologically involved axillary lymph nodes were randomly assigned to receive three courses each of epirubicin (E) 150 mg/m2, paclitaxel (P) 225 mg/m2 and cyclophosphamide (C) 2500 mg/m2 (reduced to 2000 mg/m2 after recruitment of 1200 patients) q2w intravenously (i.v.) (iddEPC-regimen) or ddEC (E 112.5 mg/m2 + C 600 mg/m2, i.v. q2w for 4 cycles) followed by paclitaxel weekly (Pw 67.5 mg/m2 i.v. q8d for 10 weeks) plus capecitabine (X 2000 mg/m2 p.o. days 1-14, q22 for 4 cycles) (ddEC-PwX-regimen). Further randomization assigned patients to ibandronate for 2 years versus observation and to pegfilgrastim day 2 versus 4. RESULTS: From June 2004 to August 2008, 2994 patients were randomized to either iddEPC (N = 1498), or ddEC-PwX (N = 1496) and started treatment. Median age was 50 years; pN1 (37.8%), pN2 (35.3%); pN3 (26.9%); 46.4% were G3 tumors; 76.9% hormone receptor-positive and 22% HER2-positive. After a median follow-up of 74 months, 645 events and 383 deaths were recorded. Hematological adverse events grades 3-4 were more common with iddEPC (P < 0.001), nonhematological with ddEC-PwX (P = 0.04), even if the toxicity profile of the two regimens was different. At 5 years, estimated disease-free survival rates for ddEC-PwX and iddEPC were 81.7% [95% confidence interval (CI) 79.5-83.6] versus 80.2% (95% CI 78.0-82.2). Hazard ratio (HR)=0.95 (95% CI 0.81-1.11, log-rank P = 0.49). Five-year overall survival rates were 89.4% for ddEC-PwX (95% CI 87.7-91.0) and 89.0% for iddEPC (95% CI 87.2-90.6), HR = 0.85 (95% CI 0.69-1.04, log-rank P = 0.10). CONCLUSION: Adding capecitabine to ddEC-Pw did not improve outcome in comparison to iddEPC but increased toxicity and should not be recommended for further use.

Dual HER2-blockade with pertuzumab and trastuzumab in HER2-positive early breast cancer: a subanalysis of data from the randomized phase III GeparSepto trial.

Background: The neoadjuvant phase III GeparSepto study showed that substituting nab-paclitaxel for standard solvent-based paclitaxel significantly improved the pathologic complete response (pCR) rate achieved with a sequential neoadjuvant chemotherapy regimen of paclitaxel, epirubicin, and cyclophosphamide for high-risk primary breast cancer. Recent trials demonstrated that in HER2+ breast cancer pCR can be increased by using pertuzumab in addition to trastuzumab and chemotherapy. The present analysis focuses on efficacy and safety data from the subset of patients with HER2+ tumors from the GeparSepto trial (n = 396) in comparison to the HER2- cohort. Patients and methods: Patients with histologically confirmed breast cancer (n = 1206) received four cycles of weekly paclitaxel [either solvent-based (Pac) or nab-paclitaxel (nab-Pac), according to randomization] followed by 4 cycles of epirubicin 90 mg/m2 plus cyclophosphamide 600 mg/m2 q3w, with concurrent trastuzumab and pertuzumab q3w for those with HER2+ tumors. The primary endpoint was pCR defined as ypT0 ypN0. Results: Higher rates of pCR were achieved in HER2+ than in HER2- tumors (57.8% versus 22.0%, P < 0.0001), with the highest rate in the HER2+/HR- cohort (71.0%; 66.7% Pac, 74.6% nab-Pac). In HER2+/HR+ tumors, the pCR rate was 52.9% (49.7% Pac, 56.4% nab-Pac). Grade ≥3 toxic effects were significantly more common in HER2+ than in HER2- patients, with grade 3-4 diarrhea in 7.6% versus 0.9% (P < 0.001) and febrile neutropenia in 6.3% versus 3.3% (P = 0.023) of patients. Left ventricular ejection fraction decreases from baseline were uncommon, with 2.0% versus 0.4% of patients showing decreases to <50% along with a ≥10% decrease from baseline. Conclusion: In HER2+ early breast cancer, a dual HER2-targeted combination of pertuzumab and trastuzumab, together with taxane-epirubicin-cyclophosphamide neoadjuvant chemotherapy, achieved high rates of pCR.

BRCA1-like profile is not significantly associated with survival benefit of non-myeloablative intensified chemotherapy in the GAIN randomized controlled trial.

PURPOSE: The BRCA1-like profile identifies tumors with a defect in homologous recombination due to inactivation of BRCA1. This profile has been shown to predict which stage III breast cancer patients benefit from myeloablative, DNA double-strand-break-inducing chemotherapy. We tested the predictive potential of the BRCA1-like profile for adjuvant non-myeloablative, intensified dose-dense chemotherapy in the GAIN trial. METHODS: Lymph node positive breast cancer patients were randomized to 3 × 3 dose-dense cycles of intensified epirubicin, paclitaxel, and cyclophosphamide (ETC) or 4 cycles concurrent epirubicin and cyclophosphamide followed by 10 cycles of weekly paclitaxel combined with 4 cycles capecitabine (EC-TX). Only triple negative breast cancer patients (TNBC) for whom tissue was available were included in these planned analyses. BRCA1-like or non-BRCA1-like copy number profiles were derived from low coverage sequencing data. RESULTS: 119 out of 163 TNBC patients (73%) had a BRCA1-like profile. After median follow-up of 83 months, disease free survival (DFS) was not significantly different between BRCA1-like and non-BRCA1-like patients [adjusted hazard ratio (adj.HR) 1.02; 95% confidence interval (CI) 0.55-1.86], neither was overall survival (OS; adj.HR 1.26; 95% CI 0.58-2.71). When split by BRCA1-like status, DFS and OS were not significantly different between treatments. However, EC-TX seemed to result in a trend to an improvement in DFS in patients with a BRCA1-like tumor, while the reverse accounted for ETC treatment in patients with a non-BRCA1-like tumor (p for interaction = 0.094). CONCLUSIONS: The BRCA1-like profile is not associated with survival benefit for a non-myeloablative, intensified regimen in this study population. Considering the limited cohort size, capecitabine might have additional benefit for TNBC patients.

Higher rate of severe toxicities in obese patients receiving dose-dense (dd) chemotherapy according to unadjusted body surface area: results of the prospectively randomized GAIN study.

BACKGROUND: In routine clinical practice, chemotherapy doses are frequently capped at a body surface area (BSA) of 2.0 m2 or adjusted to an ideal weight for obese patients due to safety reasons. MATERIALS AND METHODS: Between August 2004 and July 2008, a total of 3023 patients were enrolled in the GAIN study, a randomized phase III adjuvant trial, comparing two types of dose-dense (dd) regimen [epirubicin, docetaxel and cyclophosphamide (iddETC) versus epirubicin and cyclophosphamide (EC) followed by docetaxel (T) plus capecitabine (X)]. We retrospectively evaluated a total of 555 patients with a BMI of ≥30 for safety and outcome. RESULTS: Eighteen percent of all patients were obese: 31% of those received chemotherapy according to an unadjusted BSA. For the remaining patients, BSA was adjusted to ideal weight or was capped at 2.0 m2. A total of 15% of obese patients receiving full (unadjusted) dose of chemotherapy versus 6% of obese patients with an adjusted BSA experienced febrile neutropenia (P = 0.003) and 9% versus 3% high-grade thrombopenia (P = 0.002). Overall, 17% versus 10% had a thromboembolic event (P = 0.017), which was high grade in 13% versus 6%, respectively (P = 0.019), and 3% versus 0.3% high-grade hot flushes (P = 0.013). Dizziness (5% versus 11%; P = 0.016), diarrhea (19% versus 27%; P = 0.033) and an increase in serum creatinine (7% versus 14%; P = 0.019) were higher in the adjusted group. However, no differences in disease-free survival (DFS) and overall survival (OS) were observed between non-obese patients, obese patients receiving full-dose chemotherapy or according to an adjusted BSA [5-year DFS 81% (confidence interval 79% to 83%) versus 82% (75% to 87%) versus 81% (76% to 84%); P = 0.761; 5-year OS 90% (88% to 91%) versus 86% (80% to 91%) versus 88% (84% to 91%); P = 0.143]. CONCLUSION: Obese patients receiving dd chemotherapy according to their real BSA have a higher risk of developing severe toxicities without influencing survival. Therefore, a dose adjustment of intense dd chemotherapy should be carried out to avoid life-threatening complications.

PIK3CA mutations are associated with reduced pathological complete response rates in primary HER2-positive breast cancer: pooled analysis of 967 patients from five prospective trials investigating lapatinib and trastuzumab.

BACKGROUND: The predictive value of PIK3CA mutations in HER2 positive (HER2+) breast cancer treated with neoadjuvant anti-HER2 and chemotherapy has been reported, but the power for subgroup analyses was lacking. PATIENTS AND METHODS: We combined individual patient data from five clinical trials evaluating PIK3CA mutations and associations with pathological complete response (pCR), disease-free survival (DFS) and overall survival (OS). Patients received either trastuzumab (T), lapatinib (L) or the combination T/L in addition to a taxane-based chemotherapy. PIK3CA was genotyped in tumour biopsies taken before therapy. RESULTS: A total of 967 patients were included in this analysis; the median follow-up is 47 months. Overall, the pCR rate was significantly lower in the PIK3CA mutant compared with the wild-type group (16.2% versus 29.6%; P < 0.001). Within the hormone-receptor positive (HR+) subgroup, the PIK3CA mutant group had a pCR rate of only 7.6% compared with 24.2% in the wild-type group (P < 0.001). In contrast, in the HER2+/HR- group, there was no difference in pCR (27.2% versus 36.4%; P = 0.125) according to PIK3CA mutation status (interaction test P = 0.036). According to treatment arm, the pCR rate for mutant versus wild-type was 20.3% versus 27.1% for T (P = 0.343), 11.3% versus 16.9% for L (P = 0.369) and 16.7% versus 39.1% for T/L (P < 0.001). In the HR+ T/L group, the pCR rate was 5.5% versus 33.9% (interaction between HR and PIK3CA genotype P = 0.008). DFS and OS were not significantly different by mutation status, though the incidence rate of events was low. However, HR+/PIK3CA mutant patients seemed to have significantly worse DFS {hazard ratio (HR) 1.56 [95% confidence interval (CI) 1.00-2.45], P = 0.050; Pinteraction = 0.021}. T/L tended to improve DFS compared with T in the wild-type cohort, especially in the HR- group [HR 0.72, 95% CI (0.41-1.25), P = 0.242]. CONCLUSION: Overall PIK3CA mutant/HER2+ tumours had significantly lower pCR rates compared with wild-type tumours, however mainly confined to the HR+/PIK3CA mutant population. No definite conclusions can be drawn regarding survival.

Progression-free survival as surrogate end point for overall survival in clinical trials of HER2-targeted agents in HER2-positive metastatic breast cancer.

BACKGROUND: The gold standard end point in randomized clinical trials in metastatic breast cancer (MBC) is overall survival (OS). Although therapeutics have been approved based on progression-free survival (PFS), its use as a primary end point is controversial. We aimed to assess to what extent PFS may be used as a surrogate for OS in randomized trials of anti-HER2 agents in HER2+ MBC. METHODS: Eligible trials accrued HER2+ MBC patients in 1992-2008. A correlation approach was used: at the individual level, to estimate the association between investigator-assessed PFS and OS using a bivariate model and at the trial level, to estimate the association between treatment effects on PFS and OS. Correlation values close to 1.0 would indicate strong surrogacy. RESULTS: We identified 2545 eligible patients in 13 randomized trials testing trastuzumab or lapatinib. We collected individual patient data from 1963 patients and retained 1839 patients from 9 trials for analysis (7 first-line trials). During follow-up, 1072 deaths and 1462 progression or deaths occurred. The median survival time was 22 months [95% confidence interval (CI) 21-23 months] and the median PFS was 5.7 months (95% CI 5.5-6.1 months). At the individual level, the Spearman correlation was equal to ρ = 0.67 (95% CI 0.66-0.67) corresponding to a squared correlation value of 0.45. At the trial level, the squared correlation between treatment effects (log hazard ratios) on PFS and OS was provided by R(2) = 0.51 (95% CI 0.22-0.81). CONCLUSIONS: In trials of HER2-targeted agents in HER2+ MBC, PFS moderately correlates with OS at the individual level and treatment effects on PFS correlate moderately with those on overall mortality, providing only modest support for considering PFS as a surrogate. PFS does not completely substitute for OS in this setting.

Survival after neoadjuvant chemotherapy with or without bevacizumab or everolimus for HER2-negative primary breast cancer (GBG 44-GeparQuinto)†.

BACKGROUND: The GeparQuinto study showed that adding bevacizumab to 24 weeks of anthracycline-taxane-based neoadjuvant chemotherapy increases pathological complete response (pCR) rates overall and specifically in patients with triple-negative breast cancer (TNBC). No difference in pCR rate was observed for adding everolimus to paclitaxel in nonearly responding patients. Here, we present disease-free (DFS) and overall survival (OS) analyses. PATIENTS AND METHODS: Patients (n = 1948) with HER2-negative tumors of a median tumor size of 4 cm were randomly assigned to neoadjuvant treatment with epirubicin/cyclophosphamide followed by docetaxel (EC-T) with or without eight infusions of bevacizumab every 3 weeks before surgery. Patients without clinical response to EC ± Bevacizumab were randomized to 12 weekly cycles paclitaxel with or without everolimus 5 mg/day. To detect a hazard ratio (HR) of 0.75 (α = 0.05, ß = 0.8) 379 events had to be observed in the bevacizumab arms. RESULTS: With a median follow-up of 3.8 years, 3-year DFS was 80.8% and 3-year OS was 89.7%. Outcome was not different for patients receiving bevacizumab (HR 1.03; P = 0.784 for DFS and HR 0.974; P = 0.842 for OS) compared with patients receiving chemotherapy alone. Patients with TNBC similarly showed no improvement in DFS (HR = 0.99; P = 0.941) and OS (HR = 1.02; P = 0.891) when treated with bevacizumab. No other predefined subgroup (HR+/HER2-; locally advanced (cT4 or cN3) or not; cT1-3 or cT4; pCR or not) showed a significant benefit. No difference in DFS (HR 0.997; P = 0.987) and OS (HR 1.11; P = 0.658) was observed for nonearly responding patients receiving paclitaxel with or without everolimus overall as well as in subgroups. CONCLUSIONS: Long-term results, in opposite to the results of pCR, do not support the neoadjuvant use of bevacizumab in addition to an anthracycline-taxane-based chemotherapy or everolimus in addition to paclitaxel for nonearly responding patients. CLINICAL TRIAL NUMBER: NCT 00567554, www.clinicaltrials.gov.

Palbociclib combined with endocrine treatment in hormone receptor-positive, HER2-negative breast cancer patients with high relapse risk after neoadjuvant chemotherapy: subgroup analyses of premenopausal patients in PENELOPE-B.

BACKGROUND: The PENELOPE-B study demonstrated that the addition of 1-year post-neoadjuvant palbociclib to endocrine therapy (ET) in patients with high-risk early breast cancer (BC) did not improve invasive disease-free survival (iDFS) compared to placebo. Here, we report results for premenopausal women. PATIENTS AND METHODS: Patients with hormone receptor-positive, human epidermal growth factor receptor 2-negative BC at high risk of relapse [defined as no pathological complete response after neoadjuvant chemotherapy and a clinical, pathological stage, estrogen receptor, grading (CPS-EG) score ≥3 or 2/ypN+] were randomized to receive 13 cycles of palbociclib or placebo + standard ET. Ovarian function (OF) was evaluated by centrally assessed estradiol, follicle-stimulating hormone and anti-Müllerian hormone serum levels. RESULTS: Overall, 616 of 1250 randomized patients were premenopausal; of these, 30.0% were <40 years of age, 47.4% had four or more metastatic lymph nodes, and 58.2% had a CPS-EG score ≥3. 66.1% of patients were treated with tamoxifen alone, and 32.9% received ovarian function suppression (OFS) in addition to either tamoxifen or aromatase inhibitor (AI). After a median follow-up of 42.8 months (97.2% completeness) no difference in iDFS between palbociclib and placebo was observed [hazard ratio = 0.95, 95% confidence interval (CI) 0.69-1.30, P = 0.737]. The estimated 3-year iDFS rate was marginally higher in the palbociclib arm (80.6% versus 78.3%). Three year iDFS was higher in patients receiving AI than tamoxifen plus OFS or tamoxifen alone (86.0% versus 78.6% versus 78.0%). Patients receiving tamoxifen plus OFS showed a favorable iDFS with palbociclib (83.0% versus 74.1%, hazard ratio = 0.52, 95% CI 0.27-1.02, P = 0.057). Hematologic adverse events were more frequent with palbociclib (76.1% versus 1.9% grade 3-4, P < 0.001). Palbociclib seems not to negatively impact the OF throughout the treatment period. CONCLUSIONS: In premenopausal women, who received tamoxifen plus OFS as ET, the addition of palbociclib to ET results in a favorable iDFS. The safety profile seems favorable and in contrast to chemotherapy palbociclib does not impact OF throughout the treatment period.

Long-term outcomes of a randomized, open-label, phase II study comparing cabazitaxel versus paclitaxel as neoadjuvant treatment in patients with triple-negative or luminal B/HER2-negative breast cancer (GENEVIEVE).

BACKGROUND: The GENEVIEVE study, comparing neoadjuvant cabazitaxel versus paclitaxel in triple-negative breast cancer (TNBC) and luminal B/human epidermal growth factor receptor 2 (HER2)-negative breast cancer (BC), previously reported significant differences in pathological complete response (pCR) rates. Effects on long-term outcome are unknown. PATIENTS AND METHODS: GENEVIEVE randomized patients with cT2-3, any cN or cT1, cN+/pNSLN+, centrally confirmed TNBC or luminal B/HER2-negative BC (latter defined as estrogen/progesterone receptor-positive and >14% Ki-67-stained cells) to receive either cabazitaxel 25 mg/m2 q3w for four cycles or paclitaxel 80 mg/m2 weekly for 12 weeks. Anthracycline-containing chemotherapy was allowed in case of histologically proven invasive residuals as neoadjuvant treatment or after surgery as adjuvant treatment. Here we report the secondary endpoints invasive disease-free survival (iDFS), distant disease-free survival (DDFS), and overall survival (OS). RESULTS: Of the 333 patients randomized, 74.7% and 83.2% completed treatment in the cabazitaxel and paclitaxel arms, respectively. After a median follow-up of 89.3 months (interquartile range 68.8-97.3 months), 80 iDFS events (43 after cabazitaxel and 37 after paclitaxel) and 47 deaths (23 after cabazitaxel and 24 after paclitaxel) were reported. IDFS rates were not significantly different between the cabazitaxel and paclitaxel arms after a 3-year (83.6% versus 85.0%) and 5-year follow-up (76.2% versus 78.3%) [hazard ratio (HR) = 1.27, 95% confidence interval 0.82-1.96, P = 0.294], respectively. DDFS rates at 3 years (88.6% versus 87.8%) and 5 years (82.1% versus 82.8%) for cabazitaxel and paclitaxel were comparable (HR = 1.15, P = 0.573). Similarly, OS rates at 3 years (91.6% versus 91.8%) and 5 years (89.2% versus 86.8%) showed no significant differences (HR = 1.05, P = 0.872). Subgroup analysis for TNBC and luminal B/HER2-negative BCs indicated no significant variations in 3- or 5-year iDFS, DDFS, or OS. CONCLUSIONS: The significant differences in pCR rates observed in both treatment arms did not significantly impact long-term outcomes for patients treated with cabazitaxel versus paclitaxel in the GENEVIEVE trial.

RNA-based determination of ESR1 and HER2 expression and response to neoadjuvant chemotherapy.

BACKGROUND: Hormone and human epidermal growth factor receptor 2 (HER2) receptors are the most important breast cancer biomarkers, and additional objective and quantitative test methods such as messenger RNA (mRNA)-based quantitative analysis are urgently needed. In this study, we investigated the clinical validity of RT-PCR-based evaluation of estrogen receptor (ESR1) and HER2 mRNA expression. PATIENTS AND METHODS: A total of 1050 core biopsies from two retrospective (GeparTrio, GeparQuattro) and one prospective (PREDICT) neoadjuvant studies were evaluated by quantitative RT-PCR for ESR1 and HER2. RESULTS: ESR1 mRNA was significantly predictive for reduced response to neoadjuvant chemotherapy in univariate and multivariate analysis in all three cohorts. The complete pathologically documented response (pathological complete response, pCR) rate for ESR1+/HER2- tumors was 7.3%, 8.0% and 8.6%; for ESR1-/HER2- tumors it was 34.4%, 33.7% and 37.3% in GeparTrio, GeparQuattro and PREDICT, respectively (P < 0.001 in each cohort). In the Kaplan-Meier analysis in GeparTrio patients with ESR1+/HER2- tumors had the best prognosis, compared with ESR1-/HER2- and ESR1-/HER2+ tumors [disease-free survival (DFS): P < 0.0005, overall survival (OS): P < 0.0005]. CONCLUSIONS: Our results suggest that mRNA levels of ESR1 and HER2 predict response to neoadjuvant chemotherapy and are significantly associated with long-term outcome. As an additional option to standard immunohistochemistry and gene-array-based analysis, quantitative RT-PCR analysis might be useful for determination of the receptor status in breast cancer.

Neoadjuvant bevacizumab and anthracycline-taxane-based chemotherapy in 678 triple-negative primary breast cancers; results from the geparquinto study (GBG 44).

BACKGROUND: We evaluated the pathological complete response (pCR) rate after neoadjuvant epirubicin, (E) cyclophosphamide (C) and docetaxel containing chemotherapy with and without the addition of bevacizumab in patients with triple-negative breast cancer (TNBC). PATIENTS AND METHODS: Patients with untreated cT1c-4d TNBC represented a stratified subset of the 1948 participants of the HER2-negative part of the GeparQuinto trial. Patients were randomized to receive four cycles EC (90/600 mg/m(2); q3w) followed by four cycles docetaxel (100 mg/m(2); q3w) each with or without bevacizumab (15 mg/kg; q3w) added to chemotherapy. RESULTS: TNBC patients were randomized to chemotherapy without (n = 340) or with bevacizumab (n = 323). pCR (ypT0 ypN0, primary end point) rates were 27.9% without and 39.3% with bevacizumab (P = 0.003). According to other pCR definitions, the addition of bevacizumab increased the pCR rate from 30.9% to 41.8% (ypT0 ypN0/+; P = 0.004), 36.2% to 46.4% (ypT0/is ypN0/+; P = 0.009) and 32.9% to 43.3% (ypT0/is ypN0; P = 0.007). Bevacizumab treatment [OR 1.73, 95% confidence interval (CI) 1.23-2.42; P = 0.002], lower tumor stage (OR 2.38, 95% CI 1.24-4.54; P = 0.009) and grade 3 tumors (OR 1.68, 95% CI 1.14-2.48; P = 0.009) were confirmed as independent predictors of higher pCR in multivariate logistic regression analysis. CONCLUSIONS: The addition of bevacizumab to chemotherapy in TNBC significantly increases pCR rates.

Long-term survival of breast cancer patients with brain metastases: subanalysis of the BMBC registry.

BACKGROUND: Up to 30% of metastatic breast cancer (BC) patients develop brain metastases (BM). Prognosis of patients with BM is poor and long-term survival is rare. Identification of factors associated with long-term survival is important for improving treatment modalities. PATIENTS AND METHODS: A total of 2889 patients of the national registry for BM in BC (BMBC) were available for this analysis. Long-term survival was defined as overall survival (OS) in the upper third of the failure curve resulting in a cut-off of 15 months. A total of 887 patients were categorized as long-term survivors. RESULTS: Long-term survivors compared to other patients were younger at BC and BM diagnosis (median 48 versus 54 years and 53 versus 59 years), more often had HER2-positive tumors (59.1% versus 36.3%), less frequently luminal-like (29.1% versus 35.7%) or triple-negative breast cancer (TNBC) (11.9% versus 28.1%), showed better Eastern Cooperative Oncology Group (ECOG) performance status (PS) at the time of BM diagnosis (ECOG 0-1, 76.9% versus 51.0%), higher pathological complete remission rates after neoadjuvant chemotherapy (21.6% versus 13.7%) and lower number of BM (n = 1, BM 40.9% versus 25.4%; n = 2-3, BM 26.5% versus 26.7%; n ≥4, BM 32.6% versus 47.9%) (P < 0.001). Long-term survivors had leptomeningeal metastases (10.4% versus 17.5%) and extracranial metastases (ECM, 73.6% versus 82.5%) less frequently, and asymptomatic BM more often at the time of BM diagnosis (26.5% versus 20.1%), (P < 0.001). Median OS in long-term survivors was about two times higher than the cut-off of 15 months: 30.9 months [interquartile range (IQR) 30.3] overall, 33.9 months (IQR 37.1) in HER2-positive, 26.9 months (IQR 22.0) in luminal-like and 26.5 months (IQR 18.2) in TNBC patients. CONCLUSIONS: In our analysis, long-term survival of BC patients with BM was associated with better ECOG PS, younger age, HER2-positive subtype, lower number of BM and less extended visceral metastases. Patients with these clinical features might be more eligible for extended local brain and systemic treatment.