I had breast cancer 9 years ago, with mastectomy and 5 years tamoxifen.I am now 45. Over the past few years I have had many gynae problems, and have been told I have hyperplasia of the endometrium. Could the tamoxifen have caused it? I am waiting for biopsy results, scan and blood tests. I think i will be advised to have a hysterectomy. Has anyone had a similar experience. Thankyou.