Risk of gastrointestinal perforation in patients with metastatic breast cancer treated with bevacizumab: A meta-analysis.

Abstract

1091 Background: Bevacizumab, a vascular endothelial growth factor inhibitor, has shown to be active in patients with metastatic breast cancer (MBC) as first or second line therapy. In some tumor types, the addition of bevacizumab to chemotherapy increase the risk of gastrointestinal (GI) perforation compared with controls. The aim of this systematic review and meta-analysis of randomized trials was to assess the overall risk of GI perforation associated with bevacizumab in MBC. Methods: We selected all randomized trials which compared chemotherapy with or without bevacizumab in MBC. For the analysis, we used a fixed-effects and random effects models to calculate the pooled event-based relative risk ratios (RR) with 95% confidence interval (CI). The Cochran's Q statistic and I2 statistics were first calculated to assess the heterogeneity among the proportions of the included trials. For this study, we collected all events as reported in these trials. We did not consider differences in grade or outcomes. Results: Five trials were included in the meta-analysis: E2100, AVADO, RIBBON-1, RIBBON-2, and AVF-2119g. In total, 2,368 patients received bevacizumab-based therapy and 1,416 chemotherapy alone. GI perforation was reported in 9 and 3 patients, respectively. There was no statistical heterogeneity (p=0.532) considering all trials, so the fixed-effects model was used. Patients treated with bevacizumab-containing regimens had a RR for GI perforation, of 1.172 (95% CI, 0.342-4.016; p=0.801). Conclusions: GI perforation is an uncommon finding in patients with MBC treated with chemotherapy in the first or second line. According to this meta-analysis, the addition of bevacizumab to chemotherapy was not associated with a significant increase risk of GI perforation in this population. No significant financial relationships to disclose.