Type 2 Diabetes Mellitus and the Incidence of Epithelial Ovarian Cancer in the Cancer Prevention Study-II Nutrition Cohort
Menée entre 1992 et 2007 auprès de 63 440 femmes ménopausées incluses dans la cohorte "Cancer Prevention Study-II Nutrition", cette étude évalue l'association entre un diabète mellitus de type 2 et le risque de cancer épithélial de l'ovaire par sous-type histologique (534 cas)
Background: Despite consistent associations of type 2 diabetes mellitus (DM) with hormonally-related cancers such as breast and endometrium, the relation between type 2 DM and ovarian cancer risk is unclear. Methods: Associations of type 2 DM status, duration and insulin use with epithelial ovarian cancer overall, and with serous and non-serous histologic subtypes were examined in the Cancer Prevention Study-II Nutrition Cohort, a prospective study of U.S. men and women predominantly aged 50 years and older. Between 1992 and 2007, 524 incident epithelial ovarian cancer cases were identified among 63,440 post-menopausal women. Multivariable-adjusted relative risks (RRs) and 95% confidence intervals (CIs) were computed using extended Cox regression to updated diabetes status and bilateral oophorectomy status during follow-up. Results: Type 2 DM status (RR=1.05, 95% CI 0.75-1.46) and duration were not associated with epithelial ovarian cancer risk. Although not statistically significantly different (Pdifference=0.39), the RR was higher for type 2 DM with insulin use (RR=1.28, 95% CI 0.74, 2.24) than for type 2 DM without insulin use (RR=0.96, 95%: CI 0.64, 1.43). Diabetes appeared to be more strongly associated with non-serous (RR=1.41, 95%: CI 0.70, 2.85) than serous (RR=0.71, 95%: CI 0.41, 1.23) histologic subtypes. Conclusions: Type 2 DM was not associated with risk of epithelial ovarian cancer, although higher risks with non-serous subtypes and among insulin users cannot be ruled out. Impact: Larger studies are needed to clarify associations of type 2 DM with or without insulin use with risk of ovarian cancer overall and by histologic subtypes.