Predictive Value of the Royal Marsden Hospital Score in Second-line Immunotherapy for Metastatic NSCLC

Objective: Although immune checkpoint inhibitors have transformed routine oncology practice in the treatment of advanced non-small cell lung cancer (NSCLC), the identification of reliable predictive biomarkers, particularly in the second-line setting, remains an unmet clinical need.In this context, where programmed death-ligand 1 (PD-L1) expression alone is often inadequate, the Royal Marsden Hospital (RMH) score, which integrates objective laboratory and imaging data, has emerged as a potential prognostic tool for various cancer types.This study aims to evaluate the predictive value of the RMH score in patients with advanced NSCLC receiving second-line nivolumab and to investigate its role in stratifying patients based on treatment efficacy and survival outcomes. Material and Methods:This retrospective study explores the association between the RMH score, assessed prior to immunotherapy initiation, and survival outcomes in metastatic NSCLC patients.Fifty patients who received second-line nivolumab between 2010 and 2023 were included.The RMH score was categorized into low-risk (0-1) and high-risk (2-3) groups based on baseline serum albumin levels, lactate dehydrogenase levels, and metastatic burden.Patients with conditions affecting these biomarkers were excluded.All assessments were conducted before the initiation of nivolumab. Results:The RMH score was a significant predictor of survival in metastatic NSCLC patients receiving second-line nivolumab.High-risk patients had a median overall survival (OS) of 4 months, while those in the low-risk group had a median OS of 15 months [hazard ratio (HR)=3.1,p=0.003]; and a median progression-free survival (PFS) of 3 months versus a median PFS of 8 months in the low-risk group (HR=2.4,p=0.008).In multivariate analysis, the RMH score remained the significantly independent predictor of OS, while PD-L1 expression showed no significant impact. Conclusion:Our study highlights the RMH score, based on radiological and laboratory parameters, as a predictive marker for survival in metastatic NSCLC patients treated with second-line nivolumab.