The association of body composition phenotypes before chemotherapy with epithelial ovarian cancer mortality

The association of body composition with epithelial ovarian carcinoma (EOC) mortality is poorly understood. To date, evidence suggests high adiposity associates with decreased mortality (an obesity paradox), but the impact of muscle on this association has not been investigated. Herein, we define associations of muscle and adiposity joint-exposure body composition phenotypes with EOC mortality. Body composition from 500 women in The Body Composition and Epithelial Ovarian Cancer Survival Study was dichotomized as normal/low skeletal muscle index (SMI), a proxy for sarcopenia and high/low adiposity. Four phenotypes were classified as fit/reference (normal SMI/low adiposity; 16.2%), overweight/obese (normal SMI/high adiposity; 51.2%), sarcopenia/overweight-obese (low SMI/high adiposity; 15.6%), and sarcopenia/cachexia (low SMI/low adiposity; 17%). We used multivariable Cox models to estimate associations of each phenotype with mortality for EOC overall and high-grade serous ovarian carcinoma (HGSOC). Overweight/obesity was associated with up to 51% and 104% increased mortality in EOC and HGSOC (HR = 1.51, 95% CI: 1.05-2.19 and HR = 2.04, 95% CI: 1.29-3.21). Sarcopenia/overweight-obesity was associated with up to 66% and 67% increased mortality in EOC and HGSOC (HR = 1.66, 95% CI: 1.13-2.45 and HR = 1.67, 95% CI: 1.05-2.68). Sarcopenia/cachexia was associated with up to 73% and 109% increased mortality in EOC and HGSOC (HR = 1.73, 95% CI: 1.14-2.63 and HR = 2.09, 95% CI: 1.25-3.50). Overweight/obesity, sarcopenia/overweight-obesity and sarcopenia/cachexia phenotypes were each associated with increased mortality in EOC and HGSOC. Exercise and dietary interventions could be leveraged as ancillary treatment strategies for improving outcomes in the most fatal gynecological malignancy with no previously established modifiable prognostic factors.