Tamoxifen and endometriosis

rabi43

Hello! I'm new to this forum. I was diagnosed with BC in August 2014, about 2cm tumor with clean margins, ER positive, no lymph node involvement. I had a lumpectomy and radiation, and due to low oncotype score was able to avoid chemotherapy. Now my oncologist is recommending Tamoxifen for 10 years and I'm working on deciding whether to take it or not. My main concern is endometriosis-- I was diagnosed with endometriosis last year and underwent surgery in March 2014 to remove a tennis ball-sized ovarian cyst and blocked fallopian tube due to the endometriosis. It seems unclear how the Tamoxifen will affect that (my oncologist admitted he had no idea) and I'm trying to balance the cancer risk reduction against the possibility of making the endometriosis even worse. I am wondering if there's anyone out there who has wrestled with this issue; I'd very much like to hear what your decision was and if you were able to find any good data or research about the interactions. Thanks so much!

Moderators

Hi Rabi-

We just wanted to welcome you to our community here at BCO. We hope you find this to be a place of support and encouragement!

We're sure some of our members will be along shortly to offer their advice or share their experience with Tamoxifen. In the mean time, we found this on our main site that may be of some interest to you: http://www.breastcancer.org/treatment/side_effects.... In particular:

"Tamoxifen, a hormonal therapy, stimulates the growth of endometrial cells. This can cause endometriosis and also can increase the risk of endometrial cancer. Tamoxifen also can cause uneven thickening of the muscle and supportive tissues within the wall of the uterus."

It seems like there may be some concern that your endometriosis could get worse on the Tamoxifen. If your oncologist isn't sure about the risks, can you perhaps seek the opinion of an OBGYN?

Please let us know if we can be of any more assistance!

The Mods

thrifty1

Hi Rabi-

I'm facing the same concern as you. I have endometriosis and my Onc is wanting me to start Tamoxifen. I'm concerned if it will increase my risk even more of endometrial cancer. Have you found out anything more? Have you talked with your OBGYN? I'm going to give mine a call call today and see what he says...

Good luck

Bounce

Hello Ladies

Any updates re what you have decided to do about Tamoxifen?