PO-GG10 : Breast Cancer in Patients with Endometriosis - Results of HIRA data

Objective: Endometriosis occurs in about 10% to 15% of women in childbearing age and recurred easily even after surgery. Therefore, role of medical treatment in endometriosi is increasing. However, there are concerns about safety for the breast because most of the medication contains estrogen or progesterone. In this study, we aimed to confirm the incidence of breast cancer in endometriosis patients who received female hormone or progesterone-containing agents using the HIRA data. Methods: We compared the incidence of breast cancer among endometriosis patients who received GnRH agonist alone and those who took a female hormone or progesterone - containing drug after surgery using the HIRA database from 2008 to 2018. Results: From 2008 to 2018, a total of 1463 breast cancer cases occurred among 153,868 patients who underwent surgery for endometriosis in the HIRA database. Of these, 43% had a history of taking a product containing a female hormone or progesterone for more than 1 year, and 37% had only a GnRH agonist which showed statistically significant difference. Conclusion: In medical treatment of endometriosis, female hormone or progesterone agents for more than 1 year was more associated with breast cancer than GnRH agonist alone treatment.