@jillianb when I was prescribed Anastrozole following my mastectomy, I had taken for a year with my oncologist just asking mundane questions how ya feeling etc. When I asked him ‘ How do you know this AI is even working- as there was not a baseline of my estrogen level before I started AI and no testing following a period of time taking.’ My oncologist’s answer was “We just take it for granted “. OMG! I was out of there to never go back to him. That is not the correct response! Doctors need to be more in tuned with their breast cancer patients that they are prescribing meds to - IMHO