Adjuvant tamoxifen in breast cancer patients affects the endometrium by time, an effect remaining years after end of treatment and results in an increased frequency of endometrial carcinoma.
Tamoxifen is the most used adjuvant drug in breast cancer treatment. Its main action is as an anti-oestrogen, but in the endometrium of some patients it acts as an oestrogen. Some investigators have even reported an increased risk of developing endometrial carcinoma. The question of how to follow-up these patients and how to identify patients at risk of developing endometrial premalignant changes