Anastrozole is not Always Successful in Preventing Endometrial Hyperplasia in Patients with Estrogen (+) Breast Cancer – Case Report

Abstract

Breast cancer is the most common malignancy among women. Anastrozole is the recommended therapeutic for long-term postoperative therapy in postmenopausal women with estrogen (+) breast cancer. Its advantage over Tamoxifen lies in the fact that it does not have a stimulating effect on the proliferation of the endometrium, and therefore does not represent a risk for the development of endometrial atypia and endometrial cancer. However, it is not always 100% effective in suppressing endometrial proliferation and anaplasia. Our case shows exactly the same situation. In our case, endometrial atypia was diagnosed despite Anastrazole therapy for estrogen (+) breast cancer. The lesson that can be drawn from our case is that cases that are on long-term hormonal therapy with Anastrazole due to previous estrogen (+) breast cancer should be vigilantly monitored for the possible development of premalignant and malignant endometrial changes, including ultrasound gynecological examination at least once/6 months and, if necessary, performance of fractional exploratory curettage.