Combining Correlated Outcomes and Surrogate Endpoints in a Network Meta-Analysis of Colorectal Cancer Treatments

SIMPLE SUMMARY: Currently, cytotoxic agents and biological targeted agents are commonly combined for the treatment of advanced or metastatic colorectal cancer. However, questions of ‘which chemotherapy or targeted therapy provides the higher efficacy and lower toxicity’ or ‘whether the addition of targeted therapy to chemotherapy not only increases the treatment effect but also reduces the adverse events’ have been raised. In this study, we firstly calculated the treatment effect on overall survival, which has not been reached in several randomized controlled trials, based on treatment effects on overall response rate and/or progression-free survival. Then we performed the network meta-analysis to compare the efficacy and safety of 12 commonly used regimens. Finally, our analyses showed that FOLFOX+cetuximab and FOLFIRI+bevacizumab have high probabilities of being first-line and second-line treatments in terms of efficacy and safety, respectively. ABSTRACT: This study aimed to investigate the efficacy and safety of systemic therapies in the treatment of unresectable advanced or metastatic colorectal cancer. Predicted hazard ratios (HRs) and their 95% credible intervals (CrIs) for overall survival (OS) were calculated from the odds ratio (OR) for the overall response rate and/or HR for progression-free survival using multivariate random effects (MVRE) models. We performed a network meta-analysis (NMA) of 49 articles to compare the efficacy and safety of FOLFOX/FOLFIRI±bevacizumab (Bmab)/cetuximab (Cmab)/panitumumab (Pmab), and FOLFOXIRI/CAPEOX±Bmab. The NMA showed significant OS improvement with FOLFOX, FOLFOX+Cmab, and FOLFIRI+Cmab compared with that of FOLFIRI (HR = 0.84, 95% CrI = 0.73–0.98; HR = 0.76, 95% CrI = 0.62–0.94; HR = 0.80, 95% CrI = 0.66–0.96, respectively), as well as with FOLFOX+Cmab and FOLFIRI+Cmab compared with that of FOLFOXIRI (HR = 0.69, 95% CrI = 0.51–0.94 and HR = 0.73, 95% CrI = 0.54–0.97, respectively). The odds of adverse events grade ≥3 were significantly higher for FOLFOX+Cmab vs. FOLFIRI+Bmab (OR = 2.34, 95% CrI = 1.01–4.66). Higher odds of events were observed for FOLFIRI+Pmab in comparison with FOLFIRI (OR = 2.16, 95% CrI = 1.09–3.84) and FOLFIRI+Bmab (OR = 3.14, 95% CrI = 1.51–5.89). FOLFOX+Cmab and FOLFIRI+Bmab showed high probabilities of being first- and second-line treatments in terms of the efficacy and safety, respectively. The findings of the efficacy and safety comparisons may support the selection of appropriate treatments in clinical practice. PROSPERO registration: CRD42020153640.