Prognostic Significance of Inflammatory Biomarkers in First-Line Immunotherapy for Metastatic Melanoma: Multicentric Study

Background/Objectives: This study evaluates the prognostic value of baseline inflam-matory biomarkers neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), monocyte-to-lymphocyte ratio (MLR), lymphocyte-to-monocyte ratio (LMR), systemic immune-inflammation index (SII) and pan-immune-inflammation value (PIV) in advanced cutaneous melanoma treated with first-line immunotherapy. Methods: This multicenter retrospective study included 162 patients with unresectable stage III/IV cutaneous melanoma treated with first-line pembrolizumab, nivolumab, or nivolumab plus ipilimumab. Biomarkers were calculated from complete blood counts obtained within 30 days before treatment start. Cut-offs were defined by ROC analysis. Progression free survival (PFS) and overall survival (OS) were analyzed using Kaplan–Meier and Cox regression. Response was assessed by RECIST v1.1. Results: Higher baseline NLR, PLR, MLR, SII and PIV were more common in patients with adverse baseline features, including liver metastases, elevated LDH and poorer ECOG performance status. Patients with biomarker values below the cut-offs had sig-nificantly longer PFS and OS. In multivariable models adjusted for clinical covariates, PIV remained independently associated with the duration of PFS and OS; MLR inde-pendently predicted PFS, while PLR independently predicted OS. Conclusions: Baseline inflammatory biomarkers from routine blood counts provide useful prognostic information in advanced melanoma treated with first-line ICIs. PIV showed the most consistent independent association with survival outcomes and may support initial risk stratification alongside LDH, ECOG and metastasis pattern. However, prospective validation in independent cohorts is needed before routine clinical implementation.