HealthDay News — Tamoxifen treatment is associated with increased risk of endometrial hyperplasia, polyps, and carcinoma, as well as other uterine cancers, according to a study published online Nov. 28 in JAMA Network Open.
Ki-Jin Ryu, M.D., Ph.D., from the Korea University College of Medicine in Seoul, and colleagues examined the association of tamoxifen use with the risk of endometrial cancer and other uterine diseases in a cohort of premenopausal women aged 20 to 50 years with breast cancer diagnosis between January 2003 and December 2018. A total of 78,320 female participants were categorized into the tamoxifen and control groups (44.2 and 55.8 percent, respectively).
The researchers found that during the mean follow-up of 6.13 years, the incidence of newly diagnosed endometrial polyps, endometrial hyperplasia, endometrial cancer, and other uterine cancers was 20.13, 13.49, 2.01, and 0.45 cases per 1,000 person-years, respectively, among tamoxifen users. After adjustment for age, body mass index, history of diabetes, hypertension, dyslipidemia, polycystic ovary syndrome, gonadotropin-releasing hormone agonist treatment, and trastuzumab treatment, the risk of endometrial cancer was increased in the tamoxifen versus the control group (hazard ratio, 3.77).
“These findings suggest that awareness about the absolute risks of uterine diseases with long-term follow-up is essential for the daily management of premenopausal breast cancer survivors receiving tamoxifen and that the risk of uterine diseases in tamoxifen users, specifically in premenopausal women, should be considered,” the authors write.