Efficacy and Safety of Bevacizumab and Chemotherapy in Combination with Atezolizumab in Patients with Metastatic Colorectal Cancer: A Meta-Analysis of Randomized Controlled Trials

Background: Currently, the combination of atezolizumab, chemotherapy and bevacizumab is used to treat patients with metastatic colorectal cancer, but the effects on overall survival and safety are controversial. Therefore, this study systematically evaluated the efficacy and safety of bevacizumab, chemotherapy and atezolizumab in the treatment of this disease. Method: The English literature on treatment of colorectal cancer with bevacizumab and atezolizumab combined with chemotherapy from PubMed, Embase, Web of Science and the Cochrane Library 2023 was systematically searched until June. References were screened according to strictly defined inclusion and exclusion criteria. The included studies were evaluated for quality using Cochrane risk of bias Manual 5.3, and a meta-analysis was performed using Revman5.3. Included outcomes were progression-free survival (PFS), overall survival (OS), objective response rate (ORR), >3 Grade adverse events, and immune-related adverse events. Results: Three randomized controlled trials (RCTs) which included 791 colorectal cancer patients met the criteria. Meta-analysis results showed that bevacizumab and chemotherapy plus atezolizumab led to significantly greater PFS (hazard ratio (HR) = 0.75, 95% confidence interval (CI): 0.66 similar to 0.85, p < 0.00001) than bevacizumab and chemotherapy, with similar OS (HR = 0.97, 95% CI: 0.72 similar to 1.31, p = 0.84), ORR (odds ratio (OR) = 1.00, 95% CI: 0.67 similar to 1.49, p = 0.98), >3 Grade adverse events (OR = 1.37, 95% CI: 1.00 similar to 1.88, p = 0.05), and immune-related adverse events (OR = 3.47, 95% CI: 0.52 similar to 23.33, p = 0.20). Conclusions: Bevacizumab and chemotherapy combined with atezolizumab can prolong PFS in patients with metastatic colorectal cancer, and its safety is comparable to that of bevacizumab and chemotherapy. However, there is no significant improvement in OS and ORR of patients, more studies are needed to prove it.