Chemotherapy (CT) with or without carboplatin as neoadjuvant treatment in patients with basal-like breast cancer: GEICAM 2006-03—A multicenter, randomized phase II study.

Abstract

1015 Background: Platinum salts are active in basal-like breast cancer in preclinical models and has been widely used in clinical trials in this subtype. However its utility added to conventional drugs has never been tested in a randomized trial. This study investigates the benefit of the addition of carboplatin to conventional neoadjuvant CT in basal-like breast cancer patients. Methods: Patients (Pt) with tumors ≥ 2 cm (or less with positive axilla) and immunophenotypically defined basal-like disease (ER-/PR-/HER2-/Cytokeratin 5/6+ and/or EGFR+) assessed in a central laboratory were recruited. Pts were randomized to receive epirubicin 90 mg/m2 plus cyclophosphamide 600 mg/m2 x 4 cycles (cy) followed by either docetaxel 100 mg/m2 x 4 cy (EC-T) or docetaxel 75 mg/m2 plus carboplatin AUC 6 x 4 cy (EC-TCb). The primary end-point was pathological complete response (pCR) in the breast measured by the Miller and Payne criteria. Secondary end-points were clinical response, toxicity, type of surgery and axillary status at surgery. Results: From April-07 to January-10, 94 pts were randomized (46 EC-T, 48 EC-TCb). Pts characteristics were well balanced between arms. Median age was 47 years (27−74), 65% of pts were premenopausal, 3% grade I, 73% grade III, 10/69/19/2% were T1/T2/T3/T4 and 53% N+. One patient (in the EC-TCb arm) never received treatment and was not considered evaluable. pCR rate in the breast was 35% for EC-T and 30% for EC-TCb (p-value=0.6064 ). pCR+pN0 was 30% in both arms. Mastectomy rate was similar in both arms (EC-T: 33%, EC-TCb 28%; p-value=0.6029) Patients with any grade III-IV toxicity (excluding amenorrhea) was similar in both arms (54% and 53%), with more neutropenia and febrile neutropenia with EC-T and more anemia and trombocytopenia with EC-TCb. Conclusions: The addition of carboplatin to conventional chemotherapy with EC-T though did not increase the toxicity neither produced a better efficacy in basal-like breast cancer patients, probably because all of them had received already an alkylating agent. The findings from this trial should be taken into account in the future development of PARP inhibitors.