Significance of Platelet-to-Lymphocyte Ratio and Prognostic Nutritional Index in the Prognosis of Programmed Cell Death Protein 1 Inhibitor Therapy for Recurrent or Metastatic Head and Neck Squamous Cell Carcinoma

To predict treatment outcomes for patients with Recurrent or Metastatic Head and Neck Squamous Cell Carcinoma (R/M HNSCC) receiving programmed cell death protein 1 (PD-1) inhibitor-based immunotherapy, this protocol attempts to assess the prognostic significance of the Platelet-to-Lymphocyte Ratio (PLR) and Prognostic Nutritional Index (PNI). The research aims to enhance clinical risk classification and direct individualized treatment plans by using standardized blood-based indicators. Clinical and pathological information from 101 R/M HNSCC patients treated with PD-1 inhibitors and chemotherapy between 2019 and 2023 was retrospectively gathered. Blood samples taken within 7 days before treatment initiation were used to calculate PLR, PNI, and other inflammatory indices. Receiver operating characteristic (ROC) analysis was used to identify the appropriate cutoff values, which were then used to stratify patients into risk categories. Cutoff values for PLR, as well as SII, were determined using the Goksuluk Index (J). The Kaplan-Meier and Cox regression techniques were used to evaluate OS and Progression-Free Survival (PFS). PLR and PNI were found to be independent predictors of therapy response and illness progression by multivariate analysis. In particular, low-risk patients demonstrated noticeably higher survival outcomes, whereas high PLR and low PNI were linked to a worse prognosis. Their predictive validity was further supported by variations in the Disease Control Rate (DCR) and Objective Response Rate (ORR) between the PNI groups. This technique shows how to incorporate nutritional and hematological biomarkers into routine clinical examination for R/M HNSCC in a realistic way. This protocol offers a practical, low-cost tool to improve treatment decisions and patient outcomes in real-world oncology practice.