Efficacy and Toxicity of Addition of Bevacizumab to Chemotherapy in Patients with Metastatic Colorectal Cancer

Background: Pre-treated patients with first-line treatment can be offered a second treatment with the aim of improving their poor clinical prognosis. The therapy of metastatic colorectal cancer (CRC) patients who did not respond to first-line therapy has limited treatment options. Recently, many studies have paid much attention to the efficacy of bevacizumab as an adjuvant treatment for metastatic colorectal cancer. Objectives: We aimed to evaluate the efficacy and toxicity of bevacizumab plus chemotherapy compared with bevacizumab-naive based chemotherapy as second-line treatment in people with metastatic CRC. Methods: Electronic databases were searched for eligible studies updated to March 2018. Randomized-controlled trials comparing addition of bevacizumab to chemotherapy without bevacizumab in MCRC patients were included, of which, the main interesting results were the efficacy and safety profiles of the addition of bevacizumab in patients with MCRC as second-line therapy. Result: Five trials were eligible in the meta-analysis. Patients who received the combined bevacizumab and chemotherapy treatment in MCRC as second-line therapy showed a longer overall survival (OS) (OR=0.80,95%CI=0.72-0.89, P<0.0001) and progression-free survival (PFS) (OR=0.69,95%CI=0.61-0.77, P<0.00001). In addition, there was no significant difference in objective response rate (ORR) (RR=1.36,95%CI=0.82-2.24, P=0.23) or severe adverse event (SAE) (RR=1.02,95%CI=0.88-1.19, P=0.78) between bevacizumab-based chemotherapy and bevacizumabnaive based chemotherapy. Conclusion: Our results suggest that the addition of bevacizumab to the chemotherapy therapy could be an efficient and safe treatment option for patients with metastatic colorectal cancer as second-line therapy and without increasing the risk of an adverse event.