Psoas muscle index at the fifth lumbar vertebra as a predictor of survival in epithelial ovarian cancers.

Almost a quarter of a century has passed since the term sarcopenia was defined. Sarcopenia is recognized as a poor prognostic factor in a variety of cancer types. In ovarian cancer, it remains controversial whether sarcopenia affects prognosis and how it should be evaluated. The present study aimed to evaluate the association between the volume of the psoas major muscle and survival in patients with epithelial ovarian cancer. Medical charts of patients with epithelial ovarian cancer who received first-line chemotherapy with paclitaxel and carboplatin at the National Defense Medical College Hospital (Tokorozawa, Japan) between April 2010 and January 2015 were retrospectively reviewed. The bilateral psoas major muscle areas at the fifth lumbar vertebra were measured using computed tomography images. The Institutional Review Board at National Defense Medical College Hospital (Tokorozawa, Japan) approved the study protocol. A total of 72 patients with epithelial ovarian cancer who received combination therapy with paclitaxel and carboplatin were identified and enrolled. The median psoas muscle index (PMI; psoas muscle major cross-sectional area divided by height squared) was 5.4 cm/m (range, 3.3-10.0). Patients with higher PMI had significantly improved overall survival (OS) compared with those with lower PMI [log-rank test P=0.014; hazard ratio (HR), 2.61; 95% confidence interval (CI), 1.21-6.06]. Multivariate analysis for OS revealed that lower PMI was an independent unfavorable prognostic factor (HR, 3.87; 95% CI, 1.37-12.1; P=0.0098). The volume of psoas major muscle mass could be a potential biomarker for prognosis in patients with epithelial ovarian cancer.