Association between prognostic nutritional index and prognosis in non-small cell lung cancer patients receiving PD-1/PD-L1 inhibitors: a meta-analysis.

OBJECTIVE: This study aimed to comprehensively evaluate the predictive value of prognostic nutritional index (PNI) for long-term survival in non-small cell lung cancer (NSCLC) patients treated with programmed death receptor-1 and its ligand (PD-1/PD-L1) inhibitors through systematic review and meta-analysis. METHODS: A systematic search was conducted in PubMed, Embase, Web of Science, and the Cochrane Library databases up to January 2026. Observational studies assessing the association between PNI and survival outcomes in NSCLC patients treated with PD-1/PD-L1 inhibitors were included. Two investigators independently performed literature screening, data extraction, and methodological quality assessment (using the Newcastle-Ottawa Scale). Heterogeneity was assessed using the pooled hazard ratio (HR) and its 95% confidence interval (CI) in a random-effects model, and subgroup analyses, sensitivity analyses, and publication bias assessments were performed. RESULTS: A total of 14 studies involving 2,106 patients were included. Meta-analysis results showed that a higher PNI was associated with significantly improved overall survival (OS) (HR = 0.46, 95% CI: 0.34-0.64, p < 0.00001) and progression-free survival (PFS) (HR = 0.63, 95% CI: 0.52-0.76, p < 0.00001). Subgroup analysis indicated that the prognostic value of PNI remained consistent regardless of study region (China, Turkey, Japan, UK) or PNI cutoff value (>45 or ≤45). OS analysis showed high heterogeneity (I2 = 89%), but sensitivity analysis results were robust. Publication bias assessment suggested publication bias in OS, but after correction using pruning and complementation, the significant association between PNI and OS remained unchanged (corrected HR: 0.47, 95% CI: 0.34-0.64). CONCLUSION: Current evidence suggests an association between higher baseline PNI and improved survival outcomes in NSCLC patients receiving PD-1/PD-L1 inhibitor therapy. The PNI may serve as a candidate biomarker for risk stratification, but its clinical utility requires validation in prospective studies.