Efficacy of chemotherapy plus bevacizumab as first-line therapy in patients with metastatic colorectal cancer: a meta-analysis and up-date

Colorectal cancer (CRC) is a major cause of cancer morbidity and mortality worldwide. Bevacizumab plays an important role in the treatment of metastatic CRC (mCRC). The aim of this study was to evaluate the efficacy and safety of chemotherapy plus bevacizumab as first-line treatment in patients with mCRC. Randomized-controlled clinical trials comparing the efficacy of chemotherapy plus bevacizumab or chemotherapy alone in patients with mCRC were searched using the following electronic database of PubMed, Medline, Embase and CNKI. Total 9 trials, containing 1843 patients in chemotherapy plus bevacizumab group and 1741 patients in chemotherapy alone group, were included. Our results showed that chemotherapy plus bevacizumab statistically increased the Overall response rate (ORR) in patients with mCRC (OR = 1.57, 95% CI = 1.17-2.11, P = 0.003) in a random-effects model. The complete response rate and partial response rate were statistically increased as well (P ≤ 0.05). Subgroup analysis by bevacizumab dosage found that bevacizumab 5 mg/kg statistically increased the ORR. Significant differences were found in PFS (HR = 0.56, 95% CI = 0.46-0.69, P < 0.00001) and OS (HR = 0.83, 95% CI = 0.76-0.91, P < 0.0001) as well. No significant difference was found in adverse events. Overall, the combination of chemotherapy and bevacizumab as first-line treatment is an effective and well-tolerated regimen for patients with mCRC.