To assess the benefit of adjuvant immune checkpoint inhibitors (ICIs) among patients with solid tumors.
Approach:
Search Strategy: Systematic search of PubMed, Embase, CENTRAL, and ASCO/ESMO proceedings from January 2015 to June 2026 for phase II and III RCTs evaluating adjuvant ICIs against non-ICI controls.
Inclusion Criteria: Included studies with ICI-based adjuvant approaches and randomized comparator arms; excluded single-arm studies and those combining ICIs with non-ICI systemic therapies.
Data Analysis: Used random-effects models to pool hazard ratios (HRs) for recurrence-related outcomes (DFS/RFS/PFS) and overall survival (OS).
Key Findings:
21 RCTs included, enrolling 17,446 patients across eight solid tumors.
Adjuvant ICIs significantly improved DFS/RFS/PFS (HR 0.74, 95% CI 0.68–0.82, p<0.0001) and OS (HR 0.84, 95% CI 0.78–0.90, p<0.0001).
DFS/RFS improvements observed in melanoma (HR 0.65), urothelial carcinoma (HR 0.78), renal cell carcinoma (HR 0.84), and NSCLC (HR 0.87).
Significant OS benefits in melanoma (HR 0.76) and urothelial carcinoma (HR 0.85).
Limitations:
Small number of studies and differences at the trial level.
