Background: Both progression-free survival (PFS) and response rate (RR) are significantly improved when bevacizumab (Bev) is combined with first-line chemotherapy for locally recurrent/metastatic breast cancer (LR/mBC), as demonstrated in three randomized, phase III trials (E2100, AVADO, RIBBON-1). The benefit derived from Bev appears to be similar in triple-negative (TN) and non-TN LR/mBC according to subanalyses of the randomized trials. We conducted a subpopulation analysis of TN patients treated with first-line Bev-paclitaxel (Pac) in a large German observational study in the context of routine oncology practice. Methods: Patients with HER2-negative LR/mBC received first-line Bev-Pac according to the European label at the time of study design. Safety and efficacy data were collected for up to 1 year (or until progression, death, or Bev discontinuation if earlier). The endpoints were safety and efficacy (PFS and RR). We conducted an exploratory analysis of the subset of patients with TN disease.

Results: Of the 567 patients for whom data are currently available, 115 (20%) had TN disease. Baseline characteristics and efficacy are summarized below. Overall survival data are immature and follow-up is continuing.

Conclusions: In this ongoing study, first-line Bev-Pac demonstrated a 51% RR and median PFS of 7.7 months in patients with TN LR/mBC. These data are consistent with findings from retrospective analyses of randomized phase III trials and a subpopulation analysis of the ATHENA study. Prospective trials evaluating Bev combination regimens in TN breast cancer are ongoing.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P2-16-12.