Prognostic value of systemic inflammatory markers in renal cell carcinoma with isolated lung metastases: A retrospective analysis

Aim: Metastatic renal cell carcinoma (mRCC) with lung metastases is associated with poor prognosis, and there is a growing interest in systemic inflammatory markers as potential prognostic indicators. This study evaluates the prognostic significance of the Systemic Immune-Inflammation Index (SII), Neutrophil-to-Lymphocyte Ratio (NLR), Platelet-to- Lymphocyte Ratio (PLR), and Advanced Lung Cancer Inflammation Index (ALI) in patients with mRCC. Material and Methods: In our retrospective and multicenter study, we analyzed 76 mRCC patients with isolated lung metastases. Clinical data, including demographic characteristics, treatment details, and inflammatory markers, were collected. Patients were stratified according to the International Metastatic Renal Cell Carcinoma Database Consortium (IMDC) risk classification. The association of clinical and laboratory parameters with progression-free survival (PFS) and overall survival (OS) was analyzed using Kaplan-Meier curves and Cox proportional hazards models. Results: The median age of the patients was 61 years (IQR: 29-84), with the majority being male (74%) and smokers (57%). High SII, NLR, and PLR were significantly associated with poor IMDC risk classification (p=0.001, p=0.003, and p=0.001, respectively). Multivariate analysis identified age >65 years (HR 3.09, 95% CI 1.3-6.9, p=0.006) and high PLR (HR 5.9, 95% CI 2.2-15.8, p=0.001) as independent predictors of worse OS. ALI was not significantly associated with survival outcomes. Conclusion: Systemic inflammatory markers, particularly SII, NLR and PLR are strongly associated with poor prognosis in mRCC patients with lung metastases. These markers could be integrated into existing prognostic models to improve risk stratification and guide clinical decision-making. Further research is warranted to validate these findings and explore the underlying mechanisms linking systemic inflammation to RCC progression.