Androgenic progestins in oral contraceptives and the risk of epithelial ovarian cancer

OBJECTIVE: Oral contraceptives (OCs) have been consistently linked to reduced risk of ovarian cancer. Oral contraceptive formulations display varying degrees of androgenicity. Data linking androgens to ovarian cancer suggest that OC androgenicity may impact efficacy in preventing ovarian cancer. The authors investigated whether OC efficacy might differ according to androgenicity by using data from a large, population-based, case-control study (the Steroid Hormones and Reproductions [SHARE] Study). METHODS: Detailed data on OC formulation was obtained by an in-person interview for 568 cases and 1,026 controls. Multivariable logistic regression was used to assess the association of OC androgenicity with ovarian cancer while controlling for the known potential confounders of age, parity, family history of ovarian cancer, and tubal ligation. RESULTS: Androgenic and nonandrogenic OCs conferred a similar and significant reduction in ovarian cancer risk (odds ratio 0.52, 95% confidence interval 0.35-0.76 and odds ratio 0.59, 95% confidence interval 0.45-0.78, respectively). No differences in duration of use, age at first use, and time since last use were found between androgenic and nonandrogenic formulations. CONCLUSION: In general, the androgenicity of an OC does not alter chemopreventive efficacy. LEVEL OF EVIDENCE: II-2.