Hi,
I was on a study for Breast Cancer and the only advice I could give is to make sure you read everything you can. The medication I was on removed any excess of estrogen that I may have been producing, even after a complete hysterectomy. Not sure I can name the medication so I left it out.
I have been off of the study for about 3 months, my Oncologist feels that the med I was taking on the study may have caused the Rheumatoid Arthritis. i did a lot of research before hand but the problem was RA was not listed as a possible side effect when you research the med but when you research RA one of the causes is a dramatic change in hormone levels. I probably would have chosen to go one the study anyway because I have an 85% chance of having Breast CA return. The care you receive on a study is excellent as well.
Do a lot of research and then you can make an informed decision.
Best of luck and keep posting to let us know how it goes.
Raven