Efficacy and safety of bevacizumab-based maintenance therapy in metastatic colorectal cancer A meta-analysis

Objective: To identify the optimal treatment strategy after first-line induction chemotherapy for metastatic colorectal cancer (mCRC). Methods: We conducted a meta-analysis of randomized controlled trials comparing bevacizumab-based maintenance therapy, observation, and continuous chemotherapy. We searched the PubMed, Embase, and Cochrane databases for relevant articles published through March 2018. All randomized phase-III trials evaluating bevacizumab-based maintenance treatment after bevacizumab-based induction treatment were eligible for inclusion. The primary and secondary endpoints were progression-free survival (PFS) and overall survival (OS), respectively. Hazard ratios (HRs) with 95% confidence intervals (CIs) or data for calculating HRs with 95% CIs were extracted. The RevMan v5.3 (Copenhagen, Denmark) software was used for data analysis. Results: Nine trials (3121 patients) were included in this meta-analysis. Compared with observation alone, bevacizumab-based maintenance therapy significantly improved PFS (HR: 0.62, 95% CI: 0.47-0.82) and showed a trend toward prolonged OS (HR: 0.93, 95% CI: 0.83-1.05). The incidence of grade 3/4 toxicity, including hypertension and fatigue, was higher after maintenance therapy than after observation alone. PFS (HR: 0.91, 95% CI: 0.70-1.18) and OS (HR: 0.88, 95% CI: 0.74-1.04) did not differ between the maintenance treatment and continuous chemotherapy groups. Grade 3/4 toxicity, including diarrhea and sensory neuropathy, was less common after maintenance therapy than after continuous chemotherapy. Conclusion: Bevacizumab-based maintenance therapy significantly improved PFS, showed a trend toward prolonged OS, and reduced cumulative grade 3/4 toxicity relative to continuous chemotherapy with comparable efficacy. Although maintenance therapy was beneficial, the optimal strategy should be individualized.