Evaluation of tolerability and efficacy of incorporating carboplatin in neoadjuvant anthracycline and taxane based therapy in a BRCA1 enriched triple-negative breast cancer cohort.

PURPOSE: The addition of carboplatin (Cb) to neoadjuvant chemotherapy in triple-negative breast cancer (TNBC) has been demonstrated to improve pathologic complete response (pCR) at the expense of increased toxicity. We aimed to evaluate the effectiveness and tolerability of dose-dense anthracycline & cyclophosphamide (ddAC) followed by weekly paclitaxel (wT) in combination with weekly Cb. METHODS: Retrospective data was collected on patients with clinical stage I-III TNBC treated with neoadjuvant ddAC-wTCb (four cycles of ddA 60 mg/m2 and ddC 600 mg/m2 every 2 weeks followed by 12 cycles of wT 80 mg/m2 with Cb AUC 1.5). Indices of tolerability and pCR were evaluated and compared to a historical cohort (n = 76) treated with ddAC-T. A secondary objective was to evaluate the rates of pCR by BRCA status. RESULTS: For 43 eligible patients, mean age was 41.5 years, 51% had clinical stage II disease, 81.4% were clinically node positive and 32.6% carried a deleterious BRCA1 mutation. Only 35% completed all scheduled doses of chemotherapy. Grade 3/4 neutropenia was observed in 42.5% of patients. Overall pCR was 51.2%; 44.8% in BRCA wild-type compared to 64.3% in BRCA-associated TNBC (p = 0.232). pCR rates with ddAC-wTCb were similar to historic institutional rates with ddAC-T (51.2% vs. 51.3%, p = 0.987) and were comparable when stratified by BRCA status. In pooled multivariate analysis, only BRCA status (HR 4.00, 95%CI 1.65-9.75, p = 0.002) was significantly associated with pCR. CONCLUSION: Neoadjuvant ddAC-wTCb is less tolerable in clinical practice compared to most clinical trials, with a pCR comparable to historic rates using non-platinum regimen. The role of Cb in neoadjuvant chemotherapy for BRCA mutated TNBC remains uncertain.

Germline mutations in RAD51C in Jewish high cancer risk families.

Germline mutations in BRCA1 and BRCA2 account for ~30 % of inherited breast cancer. RAD51C was reported as an additional breast/ovarian cancer susceptibility gene in some populations. There is a paucity of data on the putative contribution of this gene to inherited breast/ovarian cancer in Jewish high risk families. High risk Jewish women, none of whom was a carrier of the predominant Jewish mutations in BRCA1 or BRCA2, were screened for RAD51C germline mutations by direct sequencing of exons and flanking intronic sequences. Overall, 206 high risk women, 79 (38.3 %) of Ashkenazi origin, were genotyped for RAD51C mutations: 190 (92.3 %) with uni- or bilateral breast cancer (mean age at diagnosis 51.3 ± 11.1 years), 14 with ovarian cancer (mean age at diagnosis 55.6 ± 8.7 years), and two with both breast and ovarian cancer. No truncating mutations were noted, and two previously described missense mutations were detected: p.Ile144Thr and p.Thr287Ala in Iraqi and mixed ethnicity Balkan-North African participants, respectively. These missense mutations were evolutionarily conserved, possibly pathogenic, based on some prediction algorithms, and were not detected in any of healthy Iraqi (n = 60) and mixed ethnicity (n = 140), cancer free controls, respectively. Germline mutations in RAD51C contribute marginally to breast and ovarian cancer susceptibility in ethnically diverse, Jewish high risk families. The p.Thr287Ala missense mutation may be a recurring, pathogenic RAD51C mutation in ethnically diverse populations.