Clinical significance of skeletal muscle density and sarcopenia in patients with pancreatic cancer undergoing first-line chemotherapy: a retrospective observational study.
Abstract Background To investigate the clinical impact of sarcopenia and skeletal muscle density among patients with metastatic pancreatic adenocarcinoma who underwent palliative first line gemcitabine-based chemotherapy. Methods A total of 330 patients with metastatic pancreatic adenocarcinoma who were treated with palliative first line gemcitabine-based chemotherapy between January 2010 and March 2017 were included in this study. Sarcopenia and skeletal muscle density status were identified by L3 vertebra level skeletal muscle index in cm 2 /m 2 and muscle attenuation in Hounsfield units using computed tomography. Results A skeletal muscle index to skeletal muscle density comparison revealed a positive correlation (R 2 = 0.058, P<0.001). Kaplan–Meier analysis showed that low skeletal muscle density was associated with poor overall survival. Multivariate analysis using Cox regression showed that low skeletal muscle index and low skeletal muscle density were poor prognostic factors for overall survival, respectively. Co-presence of low skeletal muscle index and low skeletal muscle density had more powerful prognostic implication for overall survival. Grade 3 or higher toxicity of chemotherapy was more frequently observed in patients with low skeletal muscle index and low skeletal muscle density. Overall survival was not associated with skeletal muscle density status among patients who were chemotherapy responders (complete or partial responses). However, among non-responders (stable or progressive disease), low skeletal muscle density groups had significantly poorer overall survival than did the high skeletal muscle density groups. Conclusions Sarcopenia and skeletal muscle density status can be considered a prognostic factor in patients with metastatic pancreatic adenocarcinoma who receive palliative first line gemcitabine-based chemotherapy. Severe chemotherapy toxicity occurred in the sarcopenia and low skeletal muscle density groups. Our data suggest that comprehensive assessment of skeletal muscle parameters may be more useful prognostic factors.