Leukeran and set backs

I took Leukeran for approximately 7 months in addition to Prednisone. This was 20 years ago and several of my doctors believed this put my autoimmune condition in remission. At least for 18 years it was in remission. Three endocrinologists believed my hyperthyroidism was the result of my taking Leukeran, not to mention, it also threw me into menopause at age 31. Currently, I just went back on Leukeran, in addition to being on Medrol for the past 3 months. They have tried every other medication that has not worked so well in the past 3 years with many set backs of my autoimmune problem - finally they have come back to Leukeran, which personally I'm hopeful will retain my hearing. My doctors here did not want to put me on Leukeran since they said it is too toxic. (Is there a drug that isn't toxic?)

It appears that many of the medications I have had to take (anti-cancer drugs) can cause secondary cancers. I suppose one has to outweigh the risks and what one has. In some medications, the benefit outweighs the risk.