The role of angiogenesis inhibitors re-challenge in colorectal cancer previously treated with bevacizumab: a meta-analysis of randomized controlled trials.

OBJECTIVE: The potential usefulness of angiogenesis inhibitors (AIs) re-challenge in the treatment of metastatic colorectal cancer (CRC) who previously treated with bevacizumab has not been established yet. MATERIALS AND METHODS: We identified relevant clinical studies through searching databases up to October 2016. Prospective clinical trials investigating AIs re-challenge in metastatic CRC were included for analysis. The primary endpoint was overall survival with secondary endpoint progression-free survival. Estimates of treatment effect from individual trials were combined using standard techniques. RESULTS: A total of 2.686 patients with metastatic CRC who previously received bevacizumab were identified for analysis. The meta-analysis results demonstrated that AI re-challenge significantly improved progression-free survival (hazard ratio: 0.63, 95% confidence interval: 0.52-0.76, p < 0.001) and overall survival (hazard ratio: 0.82, 95% confidence interval: 0.76-0.89, p < 0.001) when compared to non-AI containing regimens. No publication bias was detected by Begg's and Egger's tests for PFS (p = 0.09 and p = 0.32) and OS (p = 0.85 and p = 0.50). CONCLUSIONS: Our pooled analysis shows that AIs re-challenge offers an improved PFS and OS in the treatment of metastatic CRC patients who relapsed after a first-line bevacizumab-containing therapy. Further prospective clinical trials are still needed to confirm our findings.