Would you discontinue tamoxifen for endometrial hyperplasia without dysplasia in the adjuvant setting?

I would not. Endometrial hyperplasia is to be expected on tamoxifen, especially in a postmenopausal woman. It is not recommended to do a transvaginal ultrasound or endometrial biopsy without suspicion of tamoxifen. I would not change therapy in the absence of other suspicious findings.

The short answer is "it depends". Tamoxifen causes endometrial hyperplasia, especially in postmenopausal women, with reported ranges varying, but likely between 2 and 10%.

Endometrial cancer is increased in women taking tamoxifen, but remains quite uncommon, affecting 1-2 per 1000 women.

Endometrial hyperplasia without atypia is not associated with a significantly greater risk of endometrial cancer.

So, I would consider endometrial hyperplasia without atypia as a low-risk finding.

In this situat...