Predictive response factors (PRF) in an open, nonrandomized, phase II study of a combination of bevacizumab (BZ) and sequential chemotherapy as preoperative treatment in patients with operable HER2-negative breast cancer (BC).

556 Background: Association of BZ to chemotherapy in BC improves time to progression of advanced disease. However, limited studies are still available for primary treatment, and PRF are not still clearly determined, above all in HER2-negative patient subgroup receiving antiangiogenic therapy. Objectives: To determine percentage of pathologic complete responses (pCR) in patients diagnosed of locally advanced BC who receive neoadjuvant sequential therapy in association with BZ, as well as to determine the PRF and perform differential analysis of treatment resistant genes. Methods: 72 patients were included in ML20382 clinical trial. Treatment was 4 cycles of doxorubicin/cyclophosphamide 60/600 mg/m2 × 21 days, followed by 4 cycles of BZ 15 mg/kg + docetaxel 75 mg/m2 × 21 days. Median age was 46 years. Stage classification was 20.8% IIA, 43.1% IIB, 23.6% IIIA, 8.3% IIIB, 4.2% IIIC. Median tumour size was 4.75 cm. 68.1% showed axillary affectation and 80.6% were hormone-receptor positive. Clinical evaluation ...