The effect of polycystic ovarian syndrome on fibrocystic breast changes in postmenopausal women.

Background: Fibrocystic breast changes (FCCs) are benign lesions thought to be caused by an increased estrogen-to-progesterone ratio. One of the most common endocrinopathies that increases this ratio is polycystic ovarian syndrome (PCOS). Although nonproliferative FCCs do not increase the risk of breast cancer, they can make mammographic detection of malignancy in postmenopausal women more difficult. The aim of this study was to investigate the effects of PCOS on the development of postmenopausal FCCs. Methods: This retrospective cohort study used the TriNetX research network to identify two cohorts of postmenopausal women (Z78.0) older than 45, without a prior diagnosis of FCCs (N60.1) or hormone replacement therapy (Z79.890). One cohort included a diagnosis of PCOS (E28.2). The cohorts were balanced for age, race, ethnicity, and hormonally relevant comorbidities. The cohorts were then evaluated for the development of FCCs after menopause. Results: Postmenopausal patients with PCOS were 52% more likely to develop FCCs than those without PCOS (2.2% vs. 1.4%, relative risk 1.52, 95% confidence interval 1.05, 2.22, Conclusion: Postmenopausal women with PCOS have a higher risk of developing FCCs. Further studies are needed to improve the differentiation of benign FCCs from malignant lesions on imaging for postmenopausal women with PCOS who develop FCCs.