Aim: The use of bevacizumab in combination therapy is an emerging trend in metastatic colorectal cancer treatment. However, the clinical value of different combination types remains under debate. Thus, a meta-analysis of randomized controlled trials (RCTs) comparing bevacizumab-based combination therapy with monotherapy (therapy that uses one type of treatment, such as chemotherapy or surgery alone, to treat metastatic colorectal cancer) was performed, aiming to evaluate the safety and efficacy of bevacizumab-based combination therapy and to find a more beneficial combination.
Methods: We searched for clinical studies that evaluated bevacizumab-based combination therapy in metastatic colorectal cancer. We extracted data from these studies to evaluate the relative risk (RR) of overall response rate (ORR) and grade 3/4 treatment-related adverse events (AEs), HRs of overall survival (OS), and progression-free survival (PFS).
Results: Eight RCTs were identified (n=3,424). Treatments included combinations of bevacizumab and oxaliplatin, fluorouracil, and leucovorin (FOLFOX4), combinations of bevacizumab and capecitabine and oxaliplatin, combinations of bevacizumab and fluorouracil/leucovorin, combinations of bevacizumab and irinotecan, fluorouracil, and leucovorin (IFL), and combinations of bevacizumab and capecitabine. Bevacizumab-based combination therapy showed higher ORR (RR: 1.40; 95% CI: 1.10–1.78; P =0.005), PFS (HR: 0.64; 95% CI: 0.55–0.73; P =0.000), and OS (HR: 0.82; 95% CI: 0.73–0.92; P =0.001) values than monotherapy. However, higher grade 3/4 treatment-related AEs (RR: 1.27; 95% CI: 1.15–1.41; P =0.000) were observed in combination therapy than in monotherapy.
Conclusion: This meta-analysis showed that the addition of IFL to bevacizumab better benefits PFS and safety. Adding FOLFOX4 was associated with better ORR and OS. The efficacy and safety of an IFL–bevacizumab–FOLFOX4 combination should be given greater weight in future clinical trials, guidelines, and clinical practice.
Keywords: combination therapy, bevacizumab, metastatic colorectal cancer, meta-analysis