269P - Neoadjuvant Chemotherapy in Operable Breast Cancer: Data From the Aster Study (At for 3 Cycles Followed by CMF for 3 Cycles)

Abstract

ABSTRACT Background The ECTO-1 study demonstrated the efficacy of concurrent doxorubicin and paclitaxel (AT) for 4 cycles followed by cyclophosphamyde/methotrexate/fluorouracil (CMF) for 4 cycles in the neoadjuvant treatment of operable breast cancer (Gianni L. et al. Clin Cancer Res 2005). With the purpose of ameliorating the tolerability of the regimen, we designed the ASTER study to reduce both the duration and the total dose of neo-/adjuvant treatment with AT followed by CMF. Herein we report on the efficacy of the neoadjuvant portion of the trial. Methods A total of 70 patients with operable breast cancer were enrolled between September 2008 and November 2011. Median age was 51 years (range 32-73); 74% of patients presented with hormone receptor positive (HR +) and 26% of patients with hormone receptor negative (HR -); 8% of patients presented HER2 overexpression/amplification; most of the patients had cT2 (96%); half presented with node involvement cN1 (54%). Patients were treated with neoadjuvant Adriamycin (60 mg/mq) + Paclitaxel (200 mg/mq) q21 for 3 cycles followed by CMF i.v. 1, 8q28 for 3 cycles. Results The pathological complete response (pCR), defined as the absence of neoplastic cells in the primary tumor was obtained in 11.5% of cases; tnpCR, defined as the absence of neoplastic cells in the primary tumor and in nodes, was obtained in 10% of cases. Overall, 29% of patients with triple negative breast cancer achieved a pCR, while only 6% of HR positive breast cancer achieved a pCR. Conclusions Neoadjuvant treatment with three cycles of AT followed by three cycles of CMF is effective in patients with operable breast cancer. The rate of pCR matched perfectly with the data obtained with the original schema AT x 4 followed by CMF x 4 in 69 patients treated with primary chemotherapy at our institute, within the ECTO-1 study. The ASTER study sets the base for developing a less toxic chemotherapy regimen sequential and non-cross resistant containing anthracycline and taxane for the treatment of operable breast cancer. Disclosure All authors have declared no conflicts of interest.