Evaluating the Prognostic Impact of the Systemic ImmuneInflammation Index On One-Year Survival in Non-Small Cell Lung Cancer Patients Receiving Platinum-Based Chemotherapy: Initial Findings From West Sumatra, Indonesia

Background and objective: The Systemic Immune-Inflammation Index (SII) is a noninvasive biomarker derived from platelet, neutrophil, and lymphocyte counts.It functions as an objective predictor in assessing immune response and inflammation in patients with Non-Small Cell Lung Cancer (NSCLC).Despite its potential clinical value, SII remains relatively underutilized in Indonesia, particularly in West Sumatra.This study seeks to investigate the prognostic role of SII in patients with advanced-stage NSCLC.Methods: This retrospective cohort study included 65 patients diagnosed with advanced-stage NSCLC who had undergone at least three chemotherapy cycles between January 2020 and December 2022 at Dr. M Djamil Hospital, Padang.Survival duration was recorded in months, starting from the commencement of therapy until either the patient's passing or the conclusion of the observation period, with the last followup conducted in December 2023.Patients were categorized into two survival groups: those who lived for less than a year and those who survived for at least a year.The optimal SII cutoff value for predicting oneyear survival was determined through receiver operating characteristic (ROC) curve analysis.Results: The mean SII value in the group with a survival period of less than one year was higher compared to the other group (3,414.95 10/L vs. 1,517.95 10/L).ROC analysis yielded an Area Under the Curve (AUC) value of 0.745 (95% CI: 0.62-0.87).The optimal SII threshold for predicting one-year survival was identified as 1760.00 10/L, with a sensitivity of 74% and a specificity of 81%.Conclusion:.The SII serves as a promising prognostic advanced-stage NSCLC patients.