Neoadjuvant immune checkpoint inhibitors for muscle-invasive urothelial carcinoma: a systematic review and meta-analysis

INTRODUCTION: Muscle-invasive urothelial carcinoma (MIUC) represents one-quarter of cancers and carries morbidity and mortality. Although cisplatin neoadjuvant chemotherapy plus radical cystectomy improves survival, patients may be ineligible due to renal dysfunction or comorbidities. Immune checkpoint inhibitors (ICIs), established in metastatic disease, are emerging as neoadjuvant options. METHODS: < 0.05 considered significant. RESULTS: Eleven studies comprising 573 patients (82.02% male) were included. The pooled pathologic complete response (pCR) rate was 35% (95% CI: 31%-39%). Overall survival (OS), recurrence-free survival (RFS), and event-free survival (EFS) at 2 years were 85% (95% CI: 77%-90%), 78% (95% CI: 72%-83%), and 73% (95% CI: 66%-79%), respectively. Additionally, the incidence of grade ≥3 cardiovascular, hematological, and immune-related adverse events (AEs) was 3% (95% CI: 2%-6%), 16% (95% CI: 11%-23%), and 5% (95% CI: 3%-8%), respectively. CONCLUSIONS: Neoadjuvant ICIs demonstrate favorable efficacy and acceptable safety in MIUC, particularly among cisplatin-ineligible patients. Randomized trials are needed to confirm long-term oncological outcomes and establish their role in curative treatment. PROTOCOL REGISTRATION: www.crd.york.ac.uk/prospero identifier is CRD42025640278.