I was on Tamoxifen for 18 months and experienced endometrial thickening. I couldn't believe it - the drug that was supposed to be protecting me from breast cancer might be giving me uterine cancer instead?! WTF???
My GP's advice that uterine cancer was slow growing and easily treated wasn't that reassuring. Anyway several lots of scans and tests later (and let me just say I really appreciated how nice and easy breast scans are compared to a transvaginal ultrasound!) and it was decided that I didn't have uterine cancer. Yay me! But as it was determined that I was now post menopausal (thanks chemo) I was switched to Arimidex.
It would have been nice not to have to deal with all that but in the end it was ok. Just another little twist along the way.