(ChemotherapyAdvisor) – A study based on data from the Cancer Prevention Study–II Nutrition Cohort has concluded type 2 diabetes mellitus is not associated with an increased risk of epithelial ovarian cancer, American Cancer Society investigators reported in Cancer Epidemiology, Biomarkers & Prevention online August 31.
However, they noted that “higher risks with non-serous subtypes and among insulin users cannot be ruled out” and called for larger studies to clarify associations of type 2 diabetes mellitus “with or without insulin use with risk of ovarian cancer overall and by histologic subtypes.”
“Despite consistent associations of type 2 diabetes mellitus with hormonally related cancers such as breast and endometrium, the relation between type 2 diabetes mellitus and ovarian cancer risk is unclear,” the investigators wrote.
Between 1992 and 2007, they identified 524 incident epithelial ovarian cancer cases among 63,440 postmenopausal women in the Cancer Prevention Study–II Nutrition Cohort, a prospective study of U.S. men and women predominantly 50 years of age and older. Examined were associations of type 2 diabetes mellitus status, duration, and insulin use with epithelial ovarian cancer and with serous and non-serous histologic subtypes.
Results showed type 2 diabetes status and duration were not associated with increased risk of epithelial ovarian cancer (RR 1.05, 95% CI, 0.75-1.46). The relative risk was found to be higher for type 2 diabetes mellitus with insulin use (RR 1.28, 95% CI, 0.74-2.24) than for type 2 diabetes mellitus without insulin use (RR 0.96, 95% CI, 0.64-1.43); however, this difference was not statistically significant (P difference=0.39). “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,” the investigators reported.