ABSTRACT
<p><b>BACKGROUND</b>What benefits and toxicities patients acquire from the use of bevacizumab combined with firstline chemotherapy remains controversial. This study was performed to evaluate the efficacy and safety of first-line chemotherapy plus bevacizumab in patients with metastatic colorectal cancer (mCRC).</p><p><b>METHODS</b>Several databases, including PubMed, Embase, and Cochrane Library, were searched up to April 30, 2013. Eligible studies were only randomized, controlled trials (RCTs) with a direct comparison between mCRC patients treated with and without bevacizumab. Overall risk ratio (RR), hazard ratio (HR), odds ratio (OR), and 95% confidence intervals (CI) were calculated employing fixed or random-effects models depending on the heterogeneity of the included trials.</p><p><b>RESULTS</b>Six RCTs, including 1582 patients in chemotherapy plus bevacizumab group and 1484 patients in chemotherapyalone group, were included. Overall, the addition of bevacizumab to first-line chemotherapy increased overall response rate (ORR) by 4.5%, prolonged both progression-free survival (PFS) and overall survival (OS), and increased the rate of total Grades 3 or 4 adverse events (G3/4AEs) by 6.9%. Significant differences were found in ORR (RR = 1.22 (95% CI 1.01-1.46), P = 0.03), PFS (HR = 0.60 (95% CI 0.47-0.77), P < 0.0001), OS (HR = 0.83 (95% CI 0.70-0.97), P = 0.02), and any G3/4AEs (OR = 1.56 (95% CI 1.29-1.89), P < 0.00001).</p><p><b>CONCLUSION</b>Bevacizumab is a valuable addition to the current first-line chemotherapy regimens used in patients with mCRC, because of conferring a significant improvement in ORR, PFS, and OS, even though it increased adverse events.</p>