Quality is more important than quantity: pre-operative sarcopenia is associated with poor survival in advanced ovarian cancer

Background Sarcopenia is prevalent among older patients with cancer and is associated with poor outcomes. Objective To explore the relationship between muscle mass, quality, and patient age with overall survival after surgery for advanced ovarian cancer. Methods Patients with advanced stage (IIIC/IV) ovarian cancer who underwent primary cytoreductive surgery between January 2006 and July 2016 were included. Body composition measures were calculated from pre-operative CT imaging: skeletal muscle index (skeletal muscle index=skeletal muscle area normalized for height), skeletal muscle density, and skeletal muscle gauge (product of skeletal muscle index and skeletal muscle density). Each measure was transformed to a z-score and evaluated for association with risk of death using Cox proportional hazards models. Recursive partitioning was used to classify patients into homogeneous subgroups considering age and skeletal muscle gauge as predictors of overall survival. Results The study included 429 patients (mean age 64.2 years). Increased age moderately correlated with decreased skeletal muscle gauge (r=-0.45). Decreasing skeletal muscle density and skeletal muscle gauge were significantly associated with increased risk of death; HR (95% CI) per 1-unit decrease in z-score of 1.24 (1.10 to 1.39) for skeletal muscle density and 1.27 (1.12 to 1.44) for skeletal muscle gauge. Associations were diluted after adjusting for age (1.13 (1.00 to 1.29) skeletal muscle density and 1.14 (0.99 to 1.30) skeletal muscle gauge). Recursive partitioning identified three subgroups: <60 years old, >= 60 years old with skeletal muscle gauge >= 937.3, and >= 60 years old with skeletal muscle gauge <937.3; median overall survival was 5.8, 3.3, and 2.3 years, respectively (p<0.001). Conclusions Skeletal muscle gauge, a novel sarcopenia measure incorporating quantity and quality, was associated with poorer survival in patients with advanced ovarian cancer, particularly among patients older than 60. Expanding our knowledge of how sarcopenia relates to solid tumor outcomes among high-risk patients can modify our treatment approach.