Low Dose Tamoxifen for Mammographic Density Reduction

This is a dose determination study aiming to identify the optimal tamoxifen dose for reducing the risk of breast cancer. The change in mammographic density is a very good marker of therapy response. Investigators will test if 1 mg, 2.5 mg, 5 mg and 10 mg reduce the mammographic density to the same extent as 20 mg. 1440 healthy women 40-74 yrs were included when adhering the national Swedish mammography screening program between 2016- 2019. Women were randomized and treated daily for 6 months. Mammograms were taken at baseline and at end of treatment and side effects were measured throughout the study trough schedueled questionnaires and spontaneous AE-reporting.