Body composition phenotypes and long-term survival of endometrial cancer

Although overweight and obesity are associated with a higher risk of cancer, some studies have been reporting a better prognosis among overweight patients. The obesity paradox in cancer needs further investigation, since data are still controversial. The study aimed to examine if there is an association between different phenotypes of body composition and 5-year overall survival (OS) among patients with endometrial cancer.

In a retrospective cohort study, we enrolled 486 endometrial cancer patients who had computed tomography images available prior to first treatment for body composition assessment. Both adipose and skeletal muscle index (SMI) compartments were presented in tertiles. The lower tertile of SMI was considered low SMI. For visceral adipose tissue (VAT), subcutaneous adipose tissue (SAT) and total adipose tissue (TAT), values above the highest tertile were classified as high adiposity. Skeletal muscle radiodensity (SMD) was obtained by averaging the HU of skeletal muscle (SM). The primary outcome was 5-year (OS).

A significantly shorter median survival was found for patients with low SMI, low SMD, and high TAT. The combined decline in SMI and SMD had the greatest impact on survival. In adjusted Cox regression models, low SMI and low SMD were independently associated with increased mortality risk, whereas high TAT showed a protective effect against mortality. Phenotypes combining low SMI with low SMD and high or normal adipose tissue (SAT, VAT, or TAT) were linked to reduced survival, except for 'low SMI + normal SAT'. Conversely, normal SMI with high SAT and TAT was associated with lower mortality risk.

Our findings underscore the important role of SM mass, especially when combined to muscle radiodensity and adipose tissue in predicting OS in endometrial cancer patients.