Endometrial hyperplasia risk in relation to recent use of oral contraceptives and post-menopausal hormone therapy

B109

Objective: To examine the relationship between recent use of oral contraceptives and hormone therapy and risk of complex endometrial hyperplasia and endometrial hyperplasia with atypia, precancerous lesions of the lining of the uterus.
 >Methods: In this matched case-control study, cases consisted of women who were diagnosed with complex endometrial hyperplasia (n=289) or endometrial hyperplasia with atypia (n=173) between 1985-2003, and who had their diagnoses confirmed by outside research pathologists. One control was selected for each case, matched by age and enrollment status. Information on prescriptions filled were obtained from a pharmacy database. Medical records were abstracted for anthropometric measures and medical history. We used conditional logistic regression to calculate odds ratios and 95% confidence intervals.
 >Results: Only three (1.1%) women with hyperplasia had used oral contraceptives in the 6 months prior to the reference date, compared to sixteen (6.0%) controls (odds ratio 0.2; 95% confidence interval 0.0-0.6, adjusted for body mass index). Fifty-one (16.8%) cases had taken estrogen-only hormone therapy in the prior 6 months, in contrast to two (0.7%) controls (odds ratio 37.6, 95% confidence interval 8.8-160.0, adjusted for body mass index). The risk of hyperplasia among combined estrogen plus progestin hormone users in the prior 6 months did not substantially differ from that of non-hormone-users.
 >Conclusion: The present study suggests that the results of randomized trials of unopposed and combined hormone post-menopausal therapy in relation to the occurrence of endometrial hyperplasia as a whole are likely to apply specifically both to complex endometrial hyperplasia and to endometrial hyperplasia with atypia. Further examination of the association between oral contraceptives use and endometrial hyperplasia is warranted.