Gustave Roussy Immune Score and Royal Marsden Hospital Prognostic Score Are Prognostic Markers for Extensive Disease of Small Cell Lung Cancer

The Royal Marsden Hospital prognostic score (RMH score) and the Gustave Roussy immune score (GRIm-score) were developed in order to select more suitable patient for phase I trials. Lactate dehydrogenase (LDH) and serum albumin concentration are common risk factors to these two systems. As the third risk factor, the RMH score and the GRIm-score adopt number of metastatic sites and neutrophil-to-lymphocyte ratio (NLR), respectively. We aimed to investigate whether these two systems are also useful for extensive disease of small cell lung cancer (ED-SCLC).We retrospectively collected 128 patients who had initiated platinum-based chemotherapy at our hospital between September 2007 and March 2018. We divided our patients into low (score 0 - 1) and high (2 - 3) score groups, and compared overall survival (OS) and progression-free survival (PFS) between them. Multivariate Cox proportional hazard analyses found prognostic factors of survival times.Regarding GRIm-score, OS was significantly shorter in high score group than in low score group (median 6.1 vs. 11.4 months, P < 0.01), while no significant difference was observed in PFS (median 4.7 vs. 5.0 months, P = 0.12). Both OS (median 6.9 vs. 12.4 months, P < 0.01) and PFS (median 4.4 vs. 5.4 months, P = 0.01) were significantly shorter in high RMH score group than in low group. Multivariate analyses detected both high GRIm-score (hazard ratio (HR) 1.80, 95% confidence interval (CI) 1.20 - 2.72, P < 0.01) and high RMH score (HR 1.93, 95% CI 1.27 - 2.92, P < 0.01) as independent worse prognostic factors of OS, and then only high RMH score (HR 1.53, 95% CI 1.04 - 2.25, P = 0.03) as independent worse prognostic factor of PFS.Both RMH score and GRIm-score are useful as independent prognostic factors of OS in ED-SCLC. However, only RMH score is an independent prognostic factor of PFS.