Anthropometric factors and risk of endometrial cancer:: the European prospective investigation into cancer and nutrition

Objective To examine the association between anthropometry and endometrial cancer, particularly by menopausal status and exogenous hormone use subgroups. Methods Among 223,008 women in the European Prospective Investigation into Cancer and Nutrition (EPIC) study, there were 567 incident endometrial cancer cases during 6.4 years of follow-up. The analysis was performed with Cox proportional hazards modeling. Results Weight, body mass index (BMI), waist and hip circumferences and waist-hip ratio (WHR) were strongly associated with increased risk of endometrial cancer. The relative risk (RR) for obese (BMI 30- < 40 kg/m(2)) compared to normal weight (BMI < 25) women was 1.78, 95% CI = 1.41-2.26, and for morbidly obese women (BMI >= 40) was 3.02, 95% CI = 1.66-5.52. The RR for women with a waist circumference of >= 88 cm vs. < 80 cm was 1.76, 95% CI = 1.42-2.19. Adult weight gain of >= 20 kg compared with stable weight (+/- 3 kg) increased risk independent of body weight at age 20 (RR = 1.75, 95% CI = 1.11-2.77). These associations were generally stronger for postmenopausal than premenopausal women, and oral contraceptives never-users than ever-users, and much stronger among never-users of hormone replacement therapy compared to ever-users. Conclusion Obesity, abdominal adiposity, and adult weight gain were strongly associated with endometrial cancer risk. These associations were particularly evident among never-users of hormone replacement therapy.