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

Background/Objectives: This study evaluates the prognostic value of baseline inflammatory 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 significantly longer PFS and OS. In biomarker-specific multivariable models adjusted for selected clinical covariates, PIV retained the most consistent association with PFS and OS, while MLR was associated with PFS, and PLR with 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 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.