Efficacy of capecitabine (C)-based therapy in patients with first-line metastatic breast cancer (MBC) previously treated with adjuvant anthracyclines and taxanes.

665 Background: Anthracyclines and taxanes are used increasingly in neoadjuvant and adjuvant chemotherapy (CT) in breast cancer. Consequently, MBC is frequently diagnosed in anthracycline- and/or taxane-pretreated pts. Retreatment with these agents is commonly compromised by resistance and/or cumulative toxicity. C is effective in the management of first-line MBC; the current analysis was undertaken to determine the first-line clinical efficacy of C in pts pretreated with adjuvant CT. Methods: 3 studies of C 1000 mg/m2, bid, d1-14 q3w, were included: a retrospective study of single-agent C (n=226; Debled et al 2009); a phase II study of single-agent C (n=161; Kaufmann et al 2009); a phase III, randomized study (RIBBON-1) of C ± bevacizumab (A; 15mg/kg, d1 q3w; n=615). Results: Prior exposure to neoadjuvant and adjuvant CT was reported in around 50-75% of pts. Of these, around 60-75% and 40-45% received anthracyclines or taxanes, respectively. Overall response rate (ORR) and CBR (CR+PR+SD) were around 25% ...