PD-1/L1 inhibitors can improve but not replace chemotherapy for advanced urothelial carcinoma: A systematic review and network meta-analysis

Background: Programmed cell death-1/ligand 1 inhibitors are a new treatment strategy for advanced urothelial carcinoma. Therefore, a comparative evaluation of their efficacy and toxicity compared with chemotherapy is necessary. Methods: We comprehensively searched PubMed, Web of Science, Embase, and Cochrane Library databases and performed a meta-analysis of randomized controlled trials up to July 2021. We considered overall survival as the primary outcome, and progression-free survival, objective response rate, and treatment-related adverse events as secondary outcomes. Results: Overall, 3584 patients from five studies were evaluated. Compared with first-line chemotherapy, programmed cell death-1/ligand 1 inhibitors were significantly associated with worse progression-free survival (p < 0.001) and adverse objective response rates (p < 0.001). However, the treatments were not significantly different in terms of overall survival (p = 0.33). Compared with second-line chemotherapy, programmed cell death-1/ligand 1 inhibitors significantly improved overall survival (p < 0.001), and there was no statistically significant difference in progression-free survival (p = 0.89) or objective response rate (p = 0.34). Compared with chemotherapy, programmed cell death-1/ligand 1 inhibitors were well tolerated (first-line chemotherapy: p < 0.001; second-line chemotherapy: p < 0.001). Conclusions: The efficacy of programmed cell death-1/ligand 1 inhibitors in patients with advanced urothelial carcinoma is not superior to that of first-line platinum-based chemotherapy but is better than second-line chemotherapy; however, programmed cell death-1/ligand 1 inhibitors are safer than first- and second-line chemotherapy and have a broader prospect for use in combination therapy.