I had a friend and sister-in-law that was on the tamoxifen, but they both took it for breast cancer. I don't know that they were part of any studies though.
The friend actually took the full course of tamoxifen and finished it about 6 years ago. She ended up with a tumor the size of a grapefruit in her uterus; however, it was not cancer. She got a hyst., but they left her ovaries in.
This past year she discovered a lump in her "good" breast. There were actually 2. They did a needle aspiration and biopsy of the fluid. It didn't show cancer and she had to go for another mamo and ultrasound 6 months later and both spots were now gone. Thank goodness!
As for my sister-in-law. She had the breast cancer and instead of having the breast removed as my friend did, she opted for the lumpectomy with chemo and radiation.
They then put her on Tamoxifen. She did well; however, she didn't finish up her course because when she only had 6 months left of treatment she went to Hawaii with her husband for a vacation and developed a blood clot in her leg. When she returned home they discovered it and she was to be put on Coumadin.
She was told that she couldn't continue the Tamoxifen with the Coumadin therapy. She talked with her oncologist and he told her he thought she would do fine with going off the Tamoxifen and that since there was only 6 months of therapy left he thought she'd still be fine, so she stopped it.
Come to find out, you can take both drugs, but you have to have more frequent blood tests with it to watch you PT levels.
So far she's been off the Tamoxifen for about 3 years and besides getting some breast infections in the breast that had the cancer, she's been doing ok in that respect.
I don't know if this helped or not, but I figured I'd share their experieces with you.
Almost forgot, my sister-in-law also has had a hyst; however, she had it because she had severe endometriosis all over her female organs and her intestines and colon. They did leave her ovaries in though, which I thought strange.