Prognostic value of inflammation-immunity-nutrition score in cancer patients: a meta-analysis.

Cancer remains a leading cause of mortality worldwide, with inflammation and immune dysregulation playing crucial roles in tumor progression. The inflammation-immunity-nutrition score (IINS), integrating high-sensitivity C-reactive protein, lymphocyte count, and albumin, has emerged as a potential prognostic biomarker in cancer, but its generalizability across tumor types is unclear. PubMed, Cochrane Library, and EMBASE were searched for studies up to September 2025 assessing the relationship between IINS and survival outcomes in cancer patients. Hazard ratios (HRs) for overall survival (OS) and progression-free survival (PFS) were pooled using appropriate statistical models. Eight eligible articles involving 3,950 unique participants contributed 11 non-overlapping analytic cohorts. All participants were from Chinese populations, and the evidence was predominantly retrospective, with one prospectively assembled validation cohort. Elevated IINS was significantly associated with poorer OS (HR = 2.13, 95% CI: 1.56-2.90, p < 0.001) and shorter PFS (HR = 1.95, 95% CI: 1.65-2.31, p < 0.001). The binary high-versus-low analyses and the graded IINS-category analyses were based on different sets of cohorts according to the form in which effect estimates were reported. Higher IINS categories were associated with progressively less favorable survival outcomes. Elevated IINS is associated with poorer survival outcomes and may serve as an accessible prognostic marker in cancer. However, the current evidence is predominantly retrospective and entirely derived from Chinese populations. Prospective, multicentre, multiethnic validation and direct comparison with established prognostic indices are required before clinical implementation.