Assessment of sarcopenia as a predictor of poor overall survival for advanced non-small-cell lung cancer patients receiving salvage anti-PD-1 immunotherapy

BACKGROUND: Sarcopenia, which is defined as the loss of skeletal muscle mass, has been identified as a poor prognostic factor for cancer patients. This study sought to elucidate the effects of sarcopenia on the outcomes of advanced non-small cell lung cancer (NSCLC) patients receiving salvage anti-programmed death-1 (PD-1) immunotherapy. METHODS: In total, 105 NSCLC patients receiving second-line anti-PD-1 immunotherapy at the Sun Yat-sen University Cancer Center between January 2015 and December 2017 were enrolled in this study, and detailed patient data were collected. Available lumbar computed tomography images of the patients were analyzed to determine the total skeletal muscle cross-section area. The efficacy of the predictive and prognostic role of sarcopenia in progression-free survival (PFS) and overall survival (OS) was analyzed using the Kaplan-Meier method, and the risk factors were analyzed using Cox analyses. RESULTS: We found that patients with sarcopenia receiving salvage anti-PD-1 immunotherapy had significantly worse PFS (2.67 vs. 7.96 months; P<0.001) and OS (9.08 vs. 21.84 months; P<0.001) than their non-sarcopenic counterparts. We also found that sarcopenia was associated with the neutrophil-to-lymphocyte ratio (NLR) (P=0.041), and that the NLR acts as a predictor of OS. CONCLUSIONS: Sarcopenia was associated with a poor prognosis in advanced NSCLC patients receiving salvage anti-PD-1 immunotherapy. Further research needs to be conducted to identify more biomarkers and the patients most likely to benefit from immunotherapy.