Abstract PD12-07: Incidences of endometrial events and frequencies of endometrial invasive diagnostic procedures in breast cancer survivors on tamoxifen: A nationwide study

Abstract

Abstract BackgroundBreast cancer survivors who taking tamoxifen as adjuvant therapy have been reported to have more endometrial lesions. According to guidelines, a gynecological assessment is recommended for postmenopausal women, but there is no mention of premenopausal women. The purpose of this study is to compare the risk of endometrial cancer by age at diagnosis, and to investigate frequencies of gynecological exam in breast cancer patients taking tamoxifen in South Korea. MethodsA nationwide retrospective cohort study was conducted using South Korea Health Insurance Review and Assessment Service claims data. Between 2010 and 2015, a total of 60,545 (mean follow-up, 66.0 months) newly diagnosed female breast cancer survivors were included. Endometrial evaluation and Dilatation & Curettage (D&C) proportion were analyzed by age at diagnosis. The incidence of endometrial cancer and benign lesions were calculated as incident cases per person-year and analyzed with the Kaplan-Meier method. ResultsThe 26,374 patients who taking tamoxifen were divided into four groups by age at diagnosis. The incidence rate of endometrial cancer per 1,000 person-years was 1.13 and 1.45 for age range 50-59 and over 60 and 0.62 and 0.82 for in age under 40 and range 40-49. However, D&C proportion did not all differ from 10 to 11% in each subgroup. ConclusionsThis nationwide cohort study showed that the risk of endometrial cancer in premenopausal breast cancer women taking tamoxifen was lower than that of postmenopausal women. However, the invasive diagnostic procedure such as aspiration, biopsy, polypectomy and D&C was proceeding at a level that makes no difference with those in postmenopausal women. Citation Format: Soojeong Choi, Jae ho Jeong, Jinhong Jung, Young Jae Lee, Jong Won Lee, Beom Seok Ko, Byung Ho Son, Sei Hyun Ahn, Yura Lee, Hee jeong Kim, Il Yong Chung. Incidences of endometrial events and frequencies of endometrial invasive diagnostic procedures in breast cancer survivors on tamoxifen: A nationwide study [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PD12-07.