Gynecological conditions and the risk of endometrial cancer

OBJECTIVE: To examine the association between gynecological conditions (including uterine fibroids, endometriosis, pelvic inflammatory disease and infections of the tubes/womb), and risk of endometrial cancer overall and by histological subtype. METHODS: Data came from a population-based, case-control study, which included 1399 women with endometrial cancer diagnosed between 2005 and 2007 and 1539 controls. Women provided detailed risk factor information via interview or self-completed questionnaire. Logistic regression was used to calculate adjusted odds ratios (OR) and 95% confidence intervals (CI) for the association between gynecological conditions and cancer. RESULTS: A self-reported history of uterine fibroids was associated with an increased risk of endometrial cancer (OR=1.39; 95% CI: 1.10-1.74). This association was reduced for women with body-mass index≥35kg/m(2) (OR=0.71; 95% CI: 0.37-1.37), and increased in groups normally thought to be at low risk including women with normal BMI (OR=1.66; 95% CI: 1.14-2.41) and premenopausal women (OR=1.82; 95% CI: 0.99-3.32). After excluding conditions diagnosed in the previous year, we found no association between endometrial cancer and endometriosis, pelvic inflammatory disease, infections of the tubes/womb. There was no evidence that risk varied by tumor subtype. CONCLUSION: Overall these results suggest that women with uterine fibroids are at increased risk of endometrial cancer, and that greater monitoring of premenopausal and normal weight women with fibroids may be important for the early detection of endometrial cancer.