I understand your feeling of wanting to know if it is working, but I think it designed to bind to estrogen in our bodies and remove it from our system so that it cannot feed the cancer. I am not sure if knowing what that level is becomes important. However much it can remove is better than not removing any in this case. That being said, if you cannot tolerate it and your quality of life is not there, then that absolutely has to be part of the decision. You have to be living, not just breathing. If you are wanting, you might just start that conversation again with your doctor. There are certainly more choices than just tamoxifen and anastrazole. How long has it been since you quit your therapy?

Totally agree with your statement of having a baseline/benchmark prior to starting Anastrozole or others. This was not done for me. When I asked how do doctors Know med is working he said “we take it for granted “. Not a very professional answer in my book.

I got off chemo several months ago for breast cancer, HER2 positive.. I had radiation also. I don't want to take Tamoxifen. It didn't make me feel well. I talked to a friend who was miserable on it for 3 years and finally stopped. She said our oncologist admitted it only improved the chances of cancer not coming back by 2%. I asked him and he agreed that was true. He is going to find something else for me.