Identifying breast cancer patients at risk of relapse despite pathological complete response after neoadjuvant therapy.

This retrospective pooled analysis aims to identify factors predicting relapse despite a pathologic complete response (pCR) in patients with breast cancer (BC). 2066 patients with a pCR from five neoadjuvant GBG/AGO-B trials fulfill the inclusion criteria of this analysis. Primary endpoint is disease-free survival (DFS); secondary endpoints is distant DFS (DDFS) and overall survival (OS). After a median follow-up of 57.6 months, DFS is significantly worse for patients with positive lymph nodes (cN+ vs cN0 hazard ratio [HR] 1.94, 95%CI 1.48-2.54; p < 0.001). In patients with triple-negative tumors, lobular histology (lobular vs other HR 3.55, 95%CI 1.53-8.23; p = 0.003), and clinical nodal involvement (cN+ vs cN0 HR 2.45, 95%CI 1.59-3.79; p < 0.001) predict a higher risk of DFS events. Patients with HER2-positive cT3/4 tumors have a significantly higher risk of relapse (cT3/4 vs cT1 HR 2.07, 95%CI 1.06-4.03; p = 0.033). Initial tumor load and histological type predict relapse in patients with a pCR.

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

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

Utility of the CPS + EG scoring system in triple-negative breast cancer treated with neoadjuvant chemotherapy.

BACKGROUND: Pathological complete response (pCR) after neoadjuvant chemotherapy (NACT) is associated with superior survival. This association is strongest in triple-negative breast cancer (TNBC). The CPS + EG system, based on pre-treatment clinical (CS) and post-treatment pathological stage (PS), oestrogen-receptor status (E) and grade (G), leads to a refined estimate of prognosis after NACT in all-comers and hormone receptor-positive/human epidermal growth factor receptor 2 (HER2)-negative breast cancer. Here, we investigate if CPS + EG scoring provides a superior estimate of prognosis in TNBC to select patients for postneoadjuvant therapy. METHODS: We calculated the CPS + EG score for 1795 patients with TNBC from 8 prospective German trials. Five-year disease-free survival (DFS) and overall survival estimates were calculated using the Kaplan-Meier method. RESULTS: In TNBC, patients with pCR (ypT0/is ypN0, n = 822, 45.8%) had a 5-year DFS of 86%, whereas patients with residual American Joint Committee on Cancer stage I disease (n = 383; 21.3%) had a 5-year DFS of 77.5%.CPS + EG led to superior prognostic information compared with that provided by the clinical stage, but it was inferior to the prognostic information provided by the pathological stage (c-index statistics, p < 0.001). CPS + EG did not discriminate prognosis within the two best prognostic groups (score 1 and 2; n = 362; 37.2%). In contrast, pCR status added prognostic information beyond CPS + EG. Patients with a CPS + EG score of 3 had a 5-year DFS rate of 64% overall, but those with pCR had a 5-year DFS rate of 84%, and those without pCR had a 5-year DFS rate of only 49.7%. CONCLUSIONS: In TNBC, CPS + EG scoring provided inferior prognostic information compared with the pathological stage and was unable to identify patients without pCR and with a sufficiently good prognosis, who could avoid postneoadjuvant therapy. pCR remains the strongest and most clinically useful prognostic factor after NACT. Other biologic factors beyond pCR are needed in TNBC.

Therapy response and prognosis of patients with early breast cancer with low positivity for hormone receptors - An analysis of 2765 patients from neoadjuvant clinical trials.

AIM: To evaluate HER2-negative breast cancer (BC) with a low hormone receptor (HR) expression, with regard to pathological complete response (pCR) and survival, in comparison to triple-negative BC (TNBC) and strong HR-positive BC. METHODS: We compared negative [oestrogen (ER) and progesterone receptor (PR) <1%], low-positive (ER and/or PR 1-9%) and strong-positive (ER or PR 10-100%) HR-expression in neoadjuvant clinical trial cohorts (n = 2765) of BC patients. End-points were disease-free survival (DFS), distant-disease free survival (DDFS) and overall survival (OS). We performed RNA sequencing on available tumour tissue samples from patients with low-HR expression (n = 38). RESULTS: Ninety-four (3.4%) patients had low HR-positive tumours, 1769 (64.0%) had strong HR-positive tumours, and 902 (32.6%) had TNBC. There were no significant differences in pCR rates between women with low HR-positive tumours (27.7%) and women with TNBC (35.5%). DFS and DDFS were also not different [for DFS, hazard ratio 1.26, 95%-CI (confidence interval) : 0.87-1.83, log-rank test p = 0.951; for DDFS, hazard ratio 1.17, 95%-CI: 0.78-1.76, log-rank test p = 0.774]. Patients with strong HR-positive tumours had a significantly lower pCR rate (pCR 9.4%; odds ratio 0.38, 95%-CI: 0.23-0.63), but better DFS (hazard ratio 0.48, 95%-CI: 0.33-0.70) and DDFS (hazard ratio 0.49, 95%-CI: 0.33-0.74) than patients with low HR-positive tumours. Molecular subtyping (RNA sequencing) of low HR-positive tumours classified these predominantly into a basal subtype (86.8%). CONCLUSION: Low HR-positive, HER2-negative tumours have a similar clinical behaviour to TNBC showing high pCR rates and poor survival and also a basal-like gene expression signature. Patients with low HR-positive tumours should be regarded as candidates for therapy strategies targeting TNBC.

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.

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.

PIK3CA H1047R Mutation Associated with a Lower Pathological Complete Response Rate in Triple-Negative Breast Cancer Patients Treated with Anthracycline-Taxane-Based Neoadjuvant Chemotherapy.

PURPOSE: PIK3CA, encoding for subunit p110a of phosphatidylinositol 3 kinase, is frequently mutated in breast cancer. PIK3CA mutation was predictive for pathological complete response (pCR) in human epidermal growth factor 2 positive breast cancer. This study explores the association of PIK3CA mutation and pCR in triple-negative breast cancer (TNBC) treated with neoadjuvant chemotherapy. MATERIALS AND METHODS: A total of 92 patients with TNBC derived from a prospectively randomized phase II trial GeparSixto study (NCT01426880). Exon 9 and exon 20 of PIK3CA mutations were evaluated by using classical Sanger method with formalin-fixed paraffin-embedded tumor tissues. RESULTS: Seven of 90 tumors (7.8%) were detectable with a PIK3CA H1047R mutation. Overall, PIK3CA H1047R mutation was significantly associated with a lower pCR rate (14.3% vs. 56.6%; odds ratio, 0.128; 95% confidence interval [CI], 0.015 to 1.108; p=0.047). In carboplatin- containing treatment patients, H1047R mutation trended to predict a lower pCR rate (20% vs. 62.5%; p=0.146). In a multivariable analysis, H1047R mutation trended to predict a lower pCR rate (hazard ratio, 0.1; 95% CI, 0.01 to 1; p=0.056). CONCLUSION: TNBC with a PIK3CA H1047R mutation was less likely to achieve pCR after anthracycline-based neoadjuvant chemotherapy. Development of H1047R mutant selective inhibitors might be helpful to conquer this subtype of breast cancer.

Impact of Nuclear Oestrogen Receptor Beta Expression in Breast Cancer Patients Undergoing Neoadjuvant Chemotherapy.

Introduction Oestrogen receptor beta (ER-ß) is abundantly expressed in breast cancer (BC), but its impact on neoadjuvant chemotherapy outcome is unknown. Patients and Methods Patients treated in the neoadjuvant GeparTrio trial with available tissue for immunohistochemical analyses were included. Nuclear ER-ß expression was correlated with clinico-pathologic characteristics. The impact of its expression on pathological complete response (pCR [ypT0/ypN0]) and survival was determined. Results Samples of 570 patients were available. Low nuclear ER-ß expression (IRS < 9) was observed in 48.4% of hormone receptor positive and 58.6% of hormone receptor negative tumours. Low nuclear ER-ß expression was associated with higher pCR rates compared to high nuclear ER-ß expression (16.1% vs. 4.7%, p = 0.026). Low ER-ß expression was no independent predictor of pCR in multivariate analyses. Disease-free and overall survival were not statistically different between patients with high and low nuclear ER-ß expression. Triple-negative BCs showed low nuclear ER-ß expression in 57.7%, and pCR rates were 27.1% and 0% (p = 0.23) in low and high ER-ß expressing tumours, respectively. Conclusion Low ER-ß expression is associated with improved pCR rates in univariate analyses. However multivariate analyses and survival analyses do not indicate an impact of ER-ß on survival in patients undergoing neoadjuvant chemotherapy. Further examination of ER-ß as predictor for endocrine therapy might be of value.

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.

Post-Mastectomy Radiotherapy After Neoadjuvant Chemotherapy in Breast Cancer: A Pooled Retrospective Analysis of Three Prospective Randomized Trials.

BACKGROUND: The impact of locoregional radiotherapy (RT) after neoadjuvant chemotherapy (NACT) and mastectomy in breast cancer patients is currently unclear. Several publications have suggested that patients with a favorable response to NACT might not benefit from RT after mastectomy. METHODS: A retrospective analysis of three prospective randomized NACT trials was performed. Information on the use of RT was available for 817 breast cancer patients with non-inflammatory breast cancer who underwent mastectomy after NACT within the GeparTrio, GeparQuattro, and GeparQuinto-trials. RT was administered to 676 of these patients (82.7%). RESULTS: The 5-year cumulative incidence of locoregional recurrence (LRR) was 15.2% (95% confidence interval [CI] 9.0-22.8%) in patients treated without RT and 11.3% in patients treated with RT (95% CI 8.7-14.3%). In the multivariate analysis, RT was associated with a lower risk of LRR (hazard ratio 0.51, 95% CI 0.27-1.0; p = 0.05). This effect was shown especially in patients with cT3/4 tumors, as well as in patients who were cN+ before neoadjuvant therapy, including those who converted to ypN0 after neoadjuvant therapy. In the bivariate analysis, disease-free survival was significantly worse in patients who received RT, however this was not confirmed in the multivariate analysis. CONCLUSIONS: Our results suggest that RT reduces the LRR rates in breast cancer patients who receive a mastectomy after NACT without an improvement in DFS. Prospective randomized controlled trials such as the National Surgical Adjuvant Breast and Bowel Project B-51/RTOG 1304 trial will analyze whether RT has any benefit in patients who have a favorable response after NACT.

Fatal events during clinical trials: an evaluation of deaths during breast cancer studies.

BACKGROUND: Information on deaths occurring during oncological clinical trials has never been systematically assessed. Here, we examine the incidence of death and the profile of patients who died during randomized clinical breast cancer (BC) trials. METHODS: Information on fatal events during German Breast Group (GBG) led BC trials was prospectively captured. Data were derived from the trial databases and death narratives. All deaths were evaluated for possible causes, underlying conditions, treatment relatedness, time point and rate of autopsies. RESULTS: From 12/1996 to 01/2017, 23,387 patients were treated within 32 trials. Of those 88 (0.4%) died on therapy within 17 trials. Median age was 64 [range 35-84] years, 63.2% of patients had a body mass index (BMI) ≥ 25 kg/m2; 65.9% 1-3 and 22.7% ≥ 4 comorbidities; 61.4% 1-2 cardiovascular risk factors (CRFs); 26.4% took > 3 drugs; 81.7% had ECOG 0; 50.0% stage III, 76.7% luminal BC. The main causes of death were infection (38.6%; of those, 82.3% sepsis, 17.6% pneumonia), heart failure (14.8%), and pulmonary embolism (13.6%). Fatal events mainly occurred within the first 4 therapy cycles (55.7%), in the investigational arm (66.7%) and under anthracycline-taxane-based chemotherapy (51.1%). A relationship with the treatment was declared in 27.3% of the cases. An autopsy was performed in 13.6% of patients. CONCLUSIONS: Death during study treatment was mainly related to infections, and patients with advanced disease, high BMI, underlying comorbidities, CRFs and concomitant medications. If considered for study participation these patients need careful monitoring due to their higher risk for death on study.

Outcome after neoadjuvant chemotherapy in elderly breast cancer patients - a pooled analysis of individual patient data from eight prospectively randomized controlled trials.

INTRODUCTION: Recent studies showed the high and independent impact of age (<40 years) on pathologic complete response (pCR) and prognosis for patients undergoing neoadjuvant chemotherapy (NACT). Some physicians might not consider elderly patients (>65 years) for NACT due to poor prognosis or higher toxicity. The aim of this analysis is to help selecting appropriately elderly women who would benefit from NACT. Secondly, survival parameters are investigated in several histological subgroups. METHODS: From 1998 to 2010, eight prospectively randomized German Breast Group (GBG) trials of anthracycline- and taxane-based NACT were performed and analyzed in this study. RESULTS: Compared to the overall average, elderly women had significant larger tumors and more overall lymph node involvement. Histologically, they had more G2 tumors, more estrogen-receptor positive tumors. pCR (ypT0 ypN0) was strongly associated with age. The multivariable logistic regression analysis of clinical parameters showed that young age, clinical stage T4, invasive ductal cancer and poor differentiated breast cancer are predictive for high pCR. The multivariate analyses of molecular subgroups showed that age >65years is a predictor of significant lower pCR in HER2- breast cancers. Nonetheless, HER2+ patients showed pCR rates as high- and HR+/HER2+ even higher - pCR rates compared to younger patients. DISCUSSION: This study underlines the unfavorable impact of higher age on pCR, but it shows a realistic chance for pCR if NACT is applied - especially for HER2+ patients. Furthermore, elderly patients with non-TNBC showed a good prognosis (comparable to younger patients) regarding overall survival, even if they do not have pCR.

Tumour-infiltrating lymphocytes and prognosis in different subtypes of breast cancer: a pooled analysis of 3771 patients treated with neoadjuvant therapy.

BACKGROUND: Tumour-infiltrating lymphocytes (TILs) are predictive for response to neoadjuvant chemotherapy in triple-negative breast cancer (TNBC) and HER2-positive breast cancer, but their role in luminal breast cancer and the effect of TILs on prognosis in all subtypes is less clear. Here, we assessed the relevance of TILs for chemotherapy response and prognosis in patients with TNBC, HER2-positive breast cancer, and luminal-HER2-negative breast cancer. METHODS: Patients with primary breast cancer who were treated with neoadjuvant combination chemotherapy were included from six randomised trials done by the German Breast Cancer Group. Pretherapeutic core biopsies from 3771 patients included in these studies were assessed for the number of stromal TILs by standardised methods according to the guidelines of the International TIL working group. TILs were analysed both as a continuous parameter and in three predefined groups of low (0-10% immune cells in stromal tissue within the tumour), intermediate (11-59%), and high TILs (≥60%). We used these data in univariable and multivariable statistical models to assess the association between TIL concentration and pathological complete response in all patients, and between the amount of TILs and disease-free survival and overall survival in 2560 patients from five of the six clinical trial cohorts. FINDINGS: In the luminal-HER2-negative breast cancer subtype, a pathological complete response (pCR) was achieved in 45 (6%) of 759 patients with low TILs, 48 (11%) of 435 with intermediate TILs, and 49 (28%) of 172 with high TILs. In the HER2-positive subtype, pCR was observed in 194 (32%) of 605 patients with low TILs, 198 (39%) of 512 with intermediate TILs, and 127 (48%) of 262 with high TILs. Finally, in the TNBC subtype, pCR was achieved in 80 (31%) of 260 patients with low TILs, 117 (31%) of 373 with intermediate TILs, and 136 (50%) of 273 with high TILs (p<0·0001 for each subtype, χ2 test for trend). In the univariable analysis, a 10% increase in TILs was associated with longer disease-free survival in TNBC (hazard ratio [HR] 0·93 [95% CI 0·87-0·98], p=0·011) and HER2-positive breast cancer (0·94 [0·89-0·99], p=0·017), but not in luminal-HER2-negative tumours (1·02 [0·96-1·09], p=0·46). The increase in TILs was also associated with longer overall survival in TNBC (0·92 [0·86-0·99], p=0·032), but had no association in HER2-positive breast cancer (0·94 [0·86-1·02], p=0·11), and was associated with shorter overall survival in luminal-HER2-negative tumours (1·10 [1·02-1·19], p=0·011). INTERPRETATION: Increased TIL concentration predicted response to neoadjuvant chemotherapy in all molecular subtypes assessed, and was also associated with a survival benefit in HER2-positive breast cancer and TNBC. By contrast, increased TILs were an adverse prognostic factor for survival in luminal-HER2-negative breast cancer, suggesting a different biology of the immunological infiltrate in this subtype. Our data support the hypothesis that breast cancer is immunogenic and might be targetable by immune-modulating therapies. In light of the results in luminal breast cancer, further research investigating the interaction of the immune system with different types of endocrine therapy is warranted. FUNDING: Deutsche Krebshilfe and European Commission.

Clinical relevance and concordance of HER2 status in local and central testing-an analysis of 1581 HER2-positive breast carcinomas over 12 years.

Human epidermal growth factor receptor 2 (HER2) is a central predictive biomarker in breast cancer. Inaccurate HER2 results in different laboratories could be as high as 20%. However, this statement is based on data generated more than 13 years ago and may not reflect the standards of modern diagnostic pathology. We compared central and local HER2 testing in a total of 1581 HER2-positive tumors from five clinical trials. We evaluated the clinical relevance for pathological complete response (pCR) and disease-free survival in a subgroup of 677 tumors, which received an anti-HER2 therapy. Over the period of 12 years, the discordance rate for HER2 decreased from 52.4 (GeparTrio) to 8.4% (GeparSepto). Discordance rates were significantly higher in hormone receptor (HR)-positive tumors (26.6%), compared to HR-negative tumors (16.3%, P<0.0001), which could be explained by a different distribution of HER2 mRNA levels in HR-positive and HR-negative tumors. pCR rates were significantly lower in discordant tumors (13.7%) compared to concordant tumors (32.2%, GeparQuattro and GeparQuinto, P<0.001). In survival analysis, tumors with discordant HER2 testing had a reduced overall survival (OS) in the HR-negative group (P=0.019) and a trend for improved OS in the HR-positive group (P=0.125). The performance of local HER2 testing was considerably improved over time and has reached a 92% concordance, which shows that quality initiatives in diagnostic pathology are working. Tumors with discordant HER2 testing had a reduced therapy response and different survival rates.

Germline Mutation Status, Pathological Complete Response, and Disease-Free Survival in Triple-Negative Breast Cancer: Secondary Analysis of the GeparSixto Randomized Clinical Trial.

IMPORTANCE: The GeparSixto trial provided evidence that the addition of neoadjuvant carboplatin to a regimen consisting of anthracycline, taxane, and bevacizumab increases pathological complete response (pCR) rates in patients with triple-negative breast cancer (TNBC). Whether BRCA1 and BRCA2 germline mutation status affects treatment outcome remains elusive. OBJECTIVE: To determine whether BRCA1 and BRCA2 germline mutation status affects therapy response in patients with TNBC. DESIGN, SETTING, AND PARTICIPANTS: This secondary analysis of a randomized clinical trial used archived DNA samples and cancer family history of 315 patients with TNBC enrolled between August 1, 2011, and December 31, 2012, in the GeparSixto trial. In all, 291 participants (92.4%) were included in this multicenter prospective investigation. DNA samples were analyzed for germline mutations in BRCA1, BRCA2, and 16 other cancer predisposition genes. The pCR rates between the carboplatin and noncarboplatin arms were compared. Genetic analyses were performed at the Center for Familial Breast and Ovarian Cancer in Cologne, Germany; data analysis, November 1 through December 31, 2015. MAIN OUTCOMES AND MEASURES: Proportion of patients who achieved pCR and disease-free survival after neoadjuvant treatment according to BRCA1 and BRCA2 germline mutation status. For pCR rates, the ypT0/is ypN0 definition was used as a primary end point. RESULTS: Of the 291 patients with TNBC, all were women; the mean (SD) age was 48 (11) years. The pCR rate in the carboplatin group was 56.8% (83 of 146) and 41.4% (60 of 145) in the noncarboplatin group (odds ratio [OR], 1.87; 95% CI, 1.17-2.97; P = .009). Pathogenic BRCA1 and BRCA2 germline mutations were present in 50 of the 291 patients (17.2%). In the noncarboplatin arm, the pCR rate was 66.7% (16 of 24) for patients with BRCA1 and BRCA2 mutations and 36.4% (44 of 121) for patients without (OR, 3.50; 95% CI, 1.39-8.84; P = .008). The high pCR rate observed in BRCA1 and BRCA2 mutation carriers (16 of 24 [66.7%]) was not increased further by adding carboplatin (17 of 26 [65.4%]). In contrast, carboplatin increased response rates in patients without BRCA1 and BRCA2 mutations: 66 of the 120 patients (55%) without BRCA1 and BRCA2 mutations achieved pCR in the carboplatin arm vs 44 of the 121 patients (36.4%) in the noncarboplatin arm (OR, 2.14; 95% CI, 1.28-3.58; P = .004). Patients without pathogenic BRCA1 and BRCA2 alterations showed elevated disease-free survival rates when carboplatin was added (without carboplatin, 73.5%; 95% CI, 64.1%-80.8% vs with carboplatin, 85.3%; 95% CI, 77.0%-90.8%; hazard ratio, 0.53; 95% CI, 0.29-0.96; P = .04). CONCLUSIONS AND RELEVANCE: Under the nonstandard GeparSixto polychemotherapy regimen, patients without BRCA1 and BRCA2 germline mutations benefited from the addition of carboplatin and those with BRCA1 and BRCA2 mutations showed superior response rates without additive effects observed for carboplatin. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT01426880.

pCR rates in patients with bilateral breast cancer after neoadjuvant anthracycline-taxane based-chemotherapy - A retrospective pooled analysis of individual patients data of four German neoadjuvant trials.

PURPOSE: Patients with bilateral breast cancer (BBC) are usually excluded from participating in clinical trials and little is known about the response and outcome of BBC to neoadjuvant chemotherapy compared to unilateral BC (UBC). METHODS: We prospectively captured the information on patients with BBC in our database treated within four neoadjuvant chemotherapy trials and collected retrospectively the rate of pathological complete response (pCR) defined as ypT0 ypN0, ypT0/is ypN0, ypT0 ypNX, clinical and histologic parameters. Synchronous carcinoma in the contralateral breast was considered as the non-indicator lesion. Patients with UBC only treated within the same neoadjuvant trials performed the control group. RESULTS: From the 6727 patients treated within 4 German neoadjuvant trials 119 (1.8%) patients have been identified with the diagnosis of BBC. The pCR rate (ypT0 ypN0) was 12.6% in the non-indicator lesion group versus 10.9% the indicator lesion group versus 20.9% for patients with unilateral disease (p = 0.003). There were more advanced tumor stages and positive axillary lymph nodes in the indicator lesion than in the nonindicator lesion or in UBC. In 52.5% the molecular subtype was identical between indicator and non-indicator lesion with more triple negative and HER2 positive BC in the group of UBC. The disease free survival rate (DFS) was 25.8% for patients with UBC versus 39.6% for patients with BBC. CONCLUSION: The selection for the indicator lesion was based on tumor size, nodal status and inclusion criteria. Patients with BBC patients had a lower pCR rate and a lower DFS.

Tumor-Infiltrating Lymphocytes: A Predictive and Prognostic Biomarker in Neoadjuvant-Treated HER2-Positive Breast Cancer.

PURPOSE: We elucidated the value of tumor-infiltrating lymphocytes (TIL) as an independent predictor for pathologic complete response (pCR) rate and as a prognostic marker for disease-free survival (DFS) in patients with HER2-positive breast cancer in the neoadjuvant setting. EXPERIMENTAL DESIGN: We evaluated stromal TILs in 498 HER2-positive breast cancer samples of the neoadjuvant GeparQuattro (G4) and GeparQuinto (G5) trials. Levels of TILs were determined as a continuous parameter per 10% increase and as lymphocyte-predominant breast cancer (LPBC; ≥ 60% TILs), and correlated with pCR rate and DFS. RESULTS: In the complete cohort, HER2-positive LPBC cases had a significantly increased pCR rates compared with non-LPBC types. They were significant predictors for pCR in univariate (10% TILs: OR 1.12, P = 0.002; LPBC: OR 2.02, P = 0.002) and multivariate analyses (10% TILs: OR 1.1, P = 0.014; LPBC: OR 1.87, P = 0.009). This effect was also detectable in the trastuzumab-treated (10% TILs: OR 1.12, P = 0.018; LPBC: OR 2.08, P = 0.013) but not in the lapatinib-treated subgroup. We identified a low-risk (pCR/LPBC) and a high-risk group (no pCR/no LPBC) regarding DFS. In triple-positive breast cancer, TILs are of more prognostic relevance than pCR. CONCLUSIONS: We could demonstrate the predictive and prognostic impact of TILs in HER2-positive breast cancer in the neoadjuvant setting. In combination with pCR rate, TILs may help to stratify prognostic subgroups, thereby guiding future therapy decisions. Clin Cancer Res; 22(23); 5747-54. ©2016 AACR.

Exploratory Cost-Effectiveness Analysis of Response-Guided Neoadjuvant Chemotherapy for Hormone Positive Breast Cancer Patients.

PURPOSE: Guiding response to neoadjuvant chemotherapy (guided-NACT) allows for an adaptative treatment approach likely to improve breast cancer survival. In this study, our primary aim is to explore the expected cost-effectiveness of guided-NACT using as a case study the first randomized controlled trial that demonstrated effectiveness (GeparTrio trial). MATERIALS AND METHODS: As effectiveness was shown in hormone-receptor positive (HR+) early breast cancers (EBC), our decision model compared the health-economic outcomes of treating a cohort of such women with guided-NACT to conventional-NACT using clinical input data from the GeparTrio trial. The expected cost-effectiveness and the uncertainty around this estimate were estimated via probabilistic cost-effectiveness analysis (CEA), from a Dutch societal perspective over a 5-year time-horizon. RESULTS: Our exploratory CEA predicted that guided-NACT as proposed by the GeparTrio, costs additional €110, but results in 0.014 QALYs gained per patient. This scenario of guided-NACT was considered cost-effective at any willingness to pay per additional QALY. At the prevailing Dutch willingness to pay threshold (€80.000/QALY) cost-effectiveness was expected with 78% certainty. CONCLUSION: This exploratory CEA indicated that guided-NACT (as proposed by the GeparTrio trial) is likely cost-effective in treating HR+ EBC women. While prospective validation of the GeparTrio findings is advisable from a clinical perspective, early CEAs can be used to prioritize further research from a broader health economic perspective, by identifying which parameters contribute most to current decision uncertainty. Furthermore, their use can be extended to explore the expected cost-effectiveness of alternative guided-NACT scenarios that combine the use of promising imaging techniques together with personalized treatments.

Integrated Analysis of PTEN and p4EBP1 Protein Expression as Predictors for pCR in HER2-Positive Breast Cancer.

BACKGROUND: The PI3K/AKT pathway and phosphatase and tensin homolog (PTEN) aberrations are common in breast cancer. We investigated the correlation between phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha (PIK3CA), PTEN, p4EBP1 (phosphorylated E4 binding protein 1), and pathologic complete response (pCR) in patients receiving neoadjuvant therapy. EXPERIMENTAL DESIGN: We retrospectively evaluated PIK3CA, PTEN, and p4EBP1 protein expression in centrally HER2-positive patients (n = 181) who received epirubicin cyclophosphamide/trastuzumab followed by docetaxel/trastuzumab alone or concomitant/followed by capecitabine within the GeparQuattro study. PTEN was assessed using the automated quantitative immunofluorescence analysis and was analyzed as a dichotomic variable. p4EBP1 was assessed by immunohistochemistry and used as a continuous and dichotomic variable. RESULTS: p4EBP1 was available from 137, PTEN from 108, and PIK3CA genotype from 83 patients. Overall, the pCR rate in PTEN-low tumors was 27.6%, and in PTEN-high tumors, it was 57.1% (P = 0.010). pCR rates were not statistically different between PIK3CA wild-type and mutant (35% vs. 22%) or p4EBP1 IRS ≤ 4 and IRS > 4 (39% vs. 33%). pCR rate was 57.1% (8/14) in PTEN-high/PIK3CA wild-type and decreased to 15.4% in PTEN-low/PIK3CA-mutant tumors (P = 0.023). In multivariable analysis adjusted for baseline parameters, PTEN independently predicted pCR in the following cohorts: overall [OR, 7.54; 95% confidence interval (CI), 2.03-28.06; P = 0.003], PIK3CA wild-type (OR, 23.81; 95% CI, 1.75-324.05; P = 0.017), p4EBP1 IRS > 4 (OR, 11.53; 95% CI, 1.84-72.24; P = 0.009), and hormone receptor-positive (OR, 40.91; 95% CI, 2.93-570.44; P = 0.006). p4EBP1 was independently predictive for pCR in PIK3CA wild-type tumors (OR, 0.14; 95% CI, 0.03-0.78; P = 0.025). CONCLUSIONS: The study showed the potential role of PIK3CA genotype, PTEN, and p4EBP in predicting pCR after anthracycline-taxane-based chemotherapy and anti-HER2 treatment. Clin Cancer Res; 22(11); 2675-83. ©2016 AACR.

Utility of the CPS+EG staging system in hormone receptor-positive, human epidermal growth factor receptor 2-negative breast cancer treated with neoadjuvant chemotherapy.

BACKGROUND: Pathologic complete response after neoadjuvant chemotherapy (NACT) correlates with overall survival (OS) in primary breast cancer. A recently described staging system based on pre-treatment clinical stage (CS), final pathological stage (PS), estrogen receptor (ER) status and nuclear grade (NG) leads to a refined estimation of prognosis in unselected patients. Its performance in luminal type breast cancers has not been determined. This study investigates the clinical utility of this CPS+EG score when restricted to hormone receptor-positive (HR+)/human epidermal growth factor receptor 2-negative (HER2-) patients and compares the results to a cohort of unselected patients. METHODS: The CPS+EG score was calculated for 6637 unselected patients and 2454 patients with HR+/HER2- tumours who received anthracycline/taxane-based NACT within 8 prospective German trials. RESULTS: Five-year disease-free survival (DFS) and OS were 75.6% and 84.1% for the unselected cohort and 80.6% and 87.8% for the HR+/HER2- subgroup, respectively. The CPS+EG system distinguished different prognostic groups with 5-year DFS ranging from 0% to 91%. The CPS+EG system leads to an improved categorisation of patients by outcome compared to CS, PS, ER or NG alone. When applying the CPS+EG score to the HR+/HER2- subgroup, a shift to lower scores was observed compared to the overall population, but 5-year DFS and OS for the individual scores were identical to that observed in the overall population. CONCLUSIONS: In HR+/HER2- patients, the CPS+EG staging system retains its ability to facilitate a refined stratification of patients according to outcome. It can help to select candidates for post-neoadjuvant clinical trials in luminal breast cancer.