Tamoxifen induced uterine changes

My mother, 70 is on tamoxifen 20 mg a day for the last 2 years for the treatment of early ca breast.

Her one year follow up ultrasonogram in 2008 was normal.

Her two year follow up ultrasonogram in 2009 showed the following;

Thickened endometrium 20mm with cystic changes.

Question; Does this require further evaluation/treatment?
Thanks

[Elaine Brown, MD]

HI!
If your mother came to see me, I would recommend an endometrial biopsy.  This is a fairly simple straightforward office procedure, and the reason to do it is to rule out endometrial cancer.  There is an eightfold increase in the risk of endometrial cancer in women who are on tamoxifen.  If endometrial cancer is ruled out, she could continue with the tamoxifen.  I would be concerned though given the findings on ultrasound that she might have hyperplasia--(pre-cancerous changes).  If so one option for treatment would be insertion of a Mirena IUD to release progesterone locally to the uterine lining.
Another option would be to switch her to one of the aromatase inhibitors such as Arimidex.  Obviously, her gyn and her oncologist should agree on the course of action.
I would NOT recommend ignoring the ultrasound findings though--early endometrial cancer is easily curable.

Good luck!
Dr B