Dr. Moore on the Use of Preventive Anastrozole Versus Tamoxifen in DCIS

Halle Moore, MD, director, Breast Medical Oncology, Department of Hematology and Oncology, Cleveland Clinic Taussig Cancer Institute, co-director, Cleveland Clinic Comprehensive Breast Cancer Program, associate professor of medicine, Cleveland Clinic Lerner College of Medicine, discusses the use of preventive anastrozole (Arimidex) versus tamoxifen in ductal carcinoma in situ (DCIS).

During the 2020 San Antonio Breast Cancer Symposium, the 12-year results of the IBIS-II trial were presented. The findings did not show any clear differences between anastrozole and tamoxifen when utilized as treatment for patients with locally excised hormone receptor–positive DCIS.

The results reinforce the fact that patients with this disease have options for treatment, says Moore. For example, a patient with severe osteoporosis may prefer to receive tamoxifen because anastrozole was associated with an increased rate of fractures. Conversely, patients who are concerned about the risk of blood clots or uterine cancer may prefer anastrozole, which demonstrated lower rates of endometrial and ovarian cancers versus anastrozole. Ultimately, the data show that both drugs would be reasonable options for patients in this setting, concludes Moore.