The Association of Abdominal Adiposity With Mortality in Patients With Stage I-III Colorectal Cancer

Background: The quantity and distribution of adipose tissue may be prognostic measures of mortality in colorectal cancer patients, and such associations may vary by patient sex. Methods: This cohort included 3262 stage I-III colorectal cancer patients. Visceral and subcutaneous adipose tissues were quantified using computed tomography. The primary endpoint was all-cause mortality. Restricted cubic splines estimated statistical associations with two-sided P values. Results: Visceral adipose tissue was prognostic of mortality in a reverse L-shaped pattern (nonlinear P = .02); risk was flat to a threshold (similar to 260 cm(2)) then increased linearly. Subcutaneous adipose tissue was prognostic of mortality in a J-shaped pattern (nonlinear P < .001); risk was higher at extreme (<50 cm(2)) but lower at intermediate values (>50 to <= 560 cm(2)). Patient sex modified the prognostic associations between visceral adipose tissue (P-interaction = .049) and subcutaneous adipose tissue (P-interaction = .04) with mortality. Among men, visceral adiposity was associated with mortality in a J-shaped pattern (nonlinear P = .003), whereas among women, visceral adiposity was associated with mortality in a linear pattern (linear P = .008). Among men, subcutaneous adiposity was associated with mortality in an L-shaped pattern (nonlinear P = .01), whereas among women, subcutaneous adiposity was associated with mortality in a J-shaped pattern (nonlinear P < .001). Conclusions: Visceral and subcutaneous adipose tissue were prognostic of mortality in patients with colorectal cancer; the shape of these associations were often nonlinear and varied by patient sex. These results offer insight into the potential biological mechanisms that link obesity with clinical outcomes in patients with cancer, suggesting that the dysregulated deposition of excess adiposity is prognostic of mortality.