Body Size and Risk of Colon Cancer in the European Prospective Investigation into Cancer and Nurtrition (EPIC)

Background: Body mass index (BMI) has been found to be associated with risk of colon cancer in men, whereas weaker associations have been reported for women. Reasons for this discrepancy are unclear but may be related to fat distribution or use of hormone replacement therapy (HRT) in women. Objective: To examine the association between anthropometry and risk of colon cancer in men and women. Design and Methods: During 6.1 years of followup, we identified 984 cases of colon cancer among 368,277 subjects free of cancer at baseline from 9 European countries. Results: BMI was significantly related to colon cancer risk in men (RR per kg/m2, 1.05; 95%-CI 1.02–1.08) but not in women (RR 1.02; 1.00–1.04; p interaction = 0.04), whereas waist-hip-ratio (WHR) was equally strong related to risk in both genders (RR per 0.1, men, 1.24; 95%-CI 1.05–1.46; women, 1.24; 1.10–1.39; p interaction = 0.92). The positive association for WHR was not apparent among postmenopausal women who used HRT. Conclusions: Abdominal obesity is an equally strong risk factor for colon cancer in both sexes and WHR is a disease predictor superior to BMI in women. The association may vary depending on HRT use in postmenopausal women; however, these findings require confirmation in future studies