Associations of skeletal muscle mass, fat mass and mortality among men and among women with stage I-III colorectal cancer

BACKGROUND: The associations of abdominal skeletal muscle mass index (SMI), visceral and subcutaneous adipose tissue (VAT and SAT respectively) and mortality among stage I-III colorectal cancer (CRC) patients may differ for men and women, but only few studies stratified their data into men and women. We investigated associations of abdominal SMI, VAT and SAT with overall mortality among men and among women with stage I-III CRC. METHODS: SMI, VAT and SAT were assessed from abdominal computed tomography (CT) images for 1,998 stage I-III CRC patients diagnosed between 2006-2015. Restricted cubic splines (RCS) were used to investigate associations of SMI, VAT and SAT with overall mortality. RESULTS: Average age of the participants was 67.9 +/- 10.6 years and 58% were men. During a median follow-up of 4.3 years, 546 (27%) patients died. Among men, the association of SMI and mortality was statistically significantly in a non-linear way in the RCS analyses, with lower SMI levels associated with higher mortality. SMI was not associated with mortality among women. SAT was associated with mortality in a non-linear way for men and for women, with lower SAT levels being associated with higher mortality. VAT was not significantly associated with mortality in men nor women. CONCLUSION: Associations of abdominal skeletal muscle mass with mortality among CRC patients were not the same for men than for women. IMPACT: This study stresses the importance for more attention for sex-related differences in body composition and cancer outcomes.