The prognostic value of the pan-immune-inflammation value in cancer patients treated with immune checkpoint inhibitors: a systematic review and meta-analysis.

OBJECTIVE: Immune checkpoint inhibitors (ICIs) show substantial therapeutic potential in advanced or metastatic solid malignancies, yet optimization of clinical benefit remains an unmet need. This systematic review and meta-analysis evaluates the pretreatment pan-immune-inflammation value (PIV) as a prognostic biomarker in ICI-treated solid tumors. METHODS: We conducted comprehensive searches in PubMed, EMBASE, Cochrane Library and Web of Science covering all records available up to January 2026. Hazard ratios (HRs) with 95% confidence intervals (CIs) were retrieved, and pooled analyses were performed using STATA 18.0 to quantify correlations between PIV and survival results. Overall survival (OS) was considered the primary outcome, with disease-free, progression-free, and recurrence-free survival (DFS/PFS/RFS) as secondary endpoints. RESULTS: Twenty-two studies comprising 28 cohorts and 3,272 participants were incorporated. Multivariate meta-analysis detected that an elevated PIV was related to shorter OS (HR = 2.31; 95% CI: 2.02-2.65; P < 0.00001) and inferior DFS/PFS/RFS (HR = 1.79; 95% CI: 1.42-2.26; P < 0.00001). Subgroup analyses denoted that follow-up duration, geographic region, PIV cutoff definitions, and cancer type may have modified the predictive performance of PIV for DFS/PFS/RFS. CONCLUSIONS: Among patients receiving ICIs, an elevated pretreatment PIV may serve as a potentially useful adverse prognostic biomarker for survival outcomes. SYSTEMATIC REVIEW REGISTRATION: https://www.crd.york.ac.uk/PROSPERO/, identifier CRD420261290575.