Prognostic significance of pre-treatment immune-inflammation biomarkers in anal cancer: A study combining real-world data and a meta-analysis

Abstract

This study examines the prognostic value of pre-treatment inflammatory biomarkers-neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and systemic inflammatory index (SII) in patients with anal cancer (AC). Blood sample analyses from 340 AC patients treated with curative (chemo)radiotherapy were retrieved from patient records to determine pre-treatment NLR, PLR, and SII values. Using receiver operating characteristic curve (RUC) analysis, the Liu method, optimal cut-offs were calculated to 2.96 for NLR, 145.31 for PLR, and 679.86 for SII. Values above the cut-off were significantly associated with worse disease-free survival (DFS) and overall survival (OS). For DFS, the hazard ratios (HRs) were 2.08 for NLR, 1.85 for PLR, and 2.13 for SII, while for OS, the HRs were 1.73 for NLR, 1.14 for PLR, and 1.76 for SII. In multivariate analyses, NLR, PLR, and SII each remained independently significant predictors of DFS. A comprehensive literature review and meta-analysis further substantiated the association between high pre-treatment NLR and OS in AC, although the findings were marked by considerable heterogeneity. These results suggest that NLR, PLR, and SII are valuable and easily measurable prognostic markers in AC. Integrating these biomarkers into clinical practice could enable more personalized treatment strategies by identifying patients at elevated risk of poorer outcomes. Future research should focus on validating these findings across diverse populations and developing standardized methodologies to optimize the clinical utility of these biomarkers.

Keywords: anal cancer; neutrophil‐to‐lymphocyte ratio; platelet‐to‐lymphocyte ratio; prognostic factors; systemic inflammatory index.