Sarcopenia and Visceral Adiposity Did Not Affect Efficacy of Immune-Checkpoint Inhibitor Monotherapy for Pretreated Patients With Advanced Non-Small Cell Lung Cancer

BACKGROUND: This study aimed to investigate the association of computed tomography (CT)-assessed sarcopenia and visceral adiposity with efficacy and prognosis of immune-checkpoint inhibitor (ICI) therapy for pretreated non-small cell lung cancer (NSCLC). METHODS: We retrospectively collected 74 patients with pretreated NSCLC who had initiated programmed cell death protein 1 (PD-1) or programmed cell death ligand 1 (PD-L1) inhibitor monotherapy between December 2015 and November 2018 at our hospital. As CT-assessed pretreatment markers, we used psoas muscle index (PMI), intramuscular adipose tissue content (IMAC), visceral-to-subcutaneous ratio (VSR) and visceral fat area (VFA) at lumbar vertebra L3 level. We divided 74 patients into high and low groups according to each Japanese sex-specific cut-off value. Using Kaplan-Meier curves and log-rank tests, we compared overall survival (OS) and progression-free survival (PFS). Adjusted by serum albumin, neutrophil-to-lymphocyte ratio, performance status and driver mutations, multivariate Cox proportional hazard analyses evaluated various variables as independent prognostic factors of OS and PFS. RESULTS: We could not find significant difference in response rate (RR) and disease control rate (DCR) between low and high groups according to any factors. The OS of patients with body mass index (BMI) < 18.5 was significantly shorter than that of patients with BMI ≥ 18.5 (median 3.3 vs. 15.8 months, P < 0.01), while there was no significant difference in OS and PFS according to PMI, IMAC, VSR and VFA. Multivariate analyses detected no significant prognostic factor in OS and PFS, except for low IMAC (hazard ratio 0.43, 95% confidence interval 0.18 - 0.998, P = 0.0496) as a favorable prognostic factor of longer OS. CONCLUSIONS: Neither PMI nor VSR, VFA might be a significant prognostic factor of PFS and OS of ICI monotherapy for pretreated NSCLC. According to our multivariate analyses, IMAC was a significant prognostic factor of OS, but not of PFS. Thus, neither sarcopenia nor visceral adiposity may be associated with the efficacy of ICI therapy.