Prognostic evaluation of the systemic immune inflammation index and lymphocyte-to-monocyte, platelet-to-lymphocyte, and neutrophil-to-lymphocyte ratios in NSCLC patients with EGFR mutations: a retrospective study at Dr. Sardjito Hospital

Abstract

Non-Small Cell Lung Cancer (NSCLC) with Epidermal Growth Factor Receptor (EGFR) mutations represents a distinct subpopulation of lung cancer that has shown increasing prevalence in Indonesia. Identifying simple hematological biomarkers like the Systemic Immune Inflammation Index (SII) and lymphocyte-to-monocyte ratio (LMR) may assist in prognostic prediction and clinical decision-making, particularly for patients undergoing targeted therapies. This retrospective cohort study evaluated the prognostic value of SII, LMR, and other inflammatory markers, including neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR), on one-year survival in 109 stage IV EGFR-mutated NSCLC patients treated with tyrosine kinase inhibitors (TKI) at Dr. Sardjito Hospital between January 2022 and December 2024. Demographic, clinical data, peripheral blood test results, and one-year survival status were analyzed. Survival analyses using Kaplan-Meier and log-rank tests were conducted according to biomarker categories, while multivariate Cox regression identified independent prognostic factors with significance set at p<0.05. Multivariate results indicated that elevated NLR and PLR were associated with increased risk of one-year death (HR 1.03, 95% CI: 0.98–1.07, p=0.15), and high PLR corresponded to decreased survival (HR 1.04, 95% CI: 0.99–1.01, p=0.33). Conversely, SII did not demonstrate a significant prognostic relationship independently, while LMR showed a protective effect on one-year survival (HR 0.9, 95% CI: 0.97–1.01, p=0.43) though without statistical significance. Kaplan-Meier analysis revealed that a high LMR significantly correlated with improved one-year survival (p<0.05). Although elevated SII, NLR, and PLR tended to associate with poorer outcomes, these trends lacked statistical significance. Overall, multivariate analysis confirmed LMR as a protective biomarker against mortality at one year, whereas SII, NLR, and PLR were not independent predictors. Thus, LMR may serve as a straightforward hematologic prognostic marker for EGFR-mutated NSCLC patients, while further validation is needed for other inflammatory biomarkers. Tailored application of these markers should consider individual clinical characteristics to improve predictive accuracy and personalize lung cancer therapy.