Anastrozole seems to be the drug of choice in Australia for estrogen-fed breast cancers. My general practioner, breast surgeon and oncologist - all females - agreed on that. Of course I have only anecdotal evidence.

My doctor switched me to Exemastane plus zoladex injections after being on Tamoxifen since I had bad side effects with Tamoxifen. I still have bad side effects but it's better than with Tamoxifen. I am relatively new to this so I haven't heard of Anastrozole.

In chat,ting with other women on here since my 1/27/2022 lumpectomy, some from the UK, some from the US, I learned that the first "drug of choice" in Europe and England seems to be Laetrozole, versus Anastrozole in the U.S. The chief reason Exemestane is not prescribed first is expense: it is far pricier than either of the other 2 and it is more "different" from Anastrozole and Laetrozole, also. I shouldn't have been prescribed any A.I. drug because of my longstanding participation in a clinical trial for those with a family history of arthritis and some sort of joint injury or damage. In my case, I fell off my bicycle on my left knee while bicycling on vacation in Green Lake, Wisconsin, in 1997. I did not seek medical treatment and could not put any weight on it for a year. I also re-injured the same knee a month or so later when I slipped on a wet marble bathroom floor in Baltmore (MD). I should have sought medical treatment from the get-go, but the couple we were vacationing with (he was a doctor) said that they "wouldn't do much" for such a knee injury, anyway. I applied to be in the MOST study, which was nationwide and went on from 1997 to 2020 until they ran out of money. I had MRIs on my damaged left knee routinely and X-rays of my hips and knees. This was a period of over 20 years, during which my knee had a few "episodes" of being very painful and I received shots for that on 2 occasions, but the pain I experienced after being put on Anastrozole, less than a week out of surgery (Feb. 1, 2022) was truly off the charts. It was the worst pain I have ever had in my life, and I've had 2 children and 3 major surgeries. I was up all night rummaging through my bathroom drawers trying to find something---ANYTHING--to alleviate all of the pain I was experiencing. Oddly enough, I had never had back problems, but my back was killing me, and I also experienced teariness, mood swings, brain fog, blurry vision from dry eyes, dry skin and vivid violent nightmares. Through all this, nobody seemed to care how I was doing, and when I tried to discuss these side effects with my oncologist, he said, "Don't take it then" and got up and walked out. My surgeon called me in for a sort of "exit interview" when I was about 7 months in and I broke down in tears relating the pain and suffering and, also, telling him how much I wished my oncologist had ordered an oncotype (which everyone else in the U.S. seemed to have gotten, and which Google said had been "standard of care" since 2013.) My surgeon suggested that a different test could be done on the tumor (11 mm) that had been removed to gauge its aggressiveness, the ki67. I had asked for the oncotype in December of 2021, when my tumor was discovered, but my oncologist in Illinois simply said, 'You don't need one." When I then asked him about the ki67, suggested by my surgeon, the oncologist said, "I won't order that for you. You'll have to get someone else' and walked out again! We never had a discussion about the 3 A.I. drugs (or anything else) and I don't know if he just didn't know about the MOST study I was in for over 20 years or if he really didn't care, since he only saw me, himself, 2 times in 8 months. So , like a good little soldier, I continued to try to live with the side effects that were literally crippling me, because my left knee blew out on September 15, 2022, as I was walking along a city street in Chcago to meet a girlfriend for lunch. I had to call an Uber to get home and it was really hard to make it to a nearby convenient care clinic, which X-rayed me on September 19th. That place gave me a pain prescription, but said I needed to find someone who could administer injections to my knee for the pain. I couldn't walk to the corner drugstore to pick up the pain pill prescription! I happened to see a joint pain clinic ad on TV for a place located in Oak Brook, IL. I called them and made an appointment and had to drive there in Chicago Rush Hour traffic to be X-rayed again, on September 21. They injected me with 32 ml of an anti-inflammatory, because Anastrozole (or any of the A.I. drugs) will inflame previously injured joints, as I learned firsthand. I was given Tramadol for pain (50 mg.) and I hobbled with a cane and/or had to use a wheelchair, later, for over 6 months. The symptoms mimicked a Meniscus Tear and were very painful. I went back to my home city and had a 3rd X--ray and, when I met with my oncologist for only the second time in 8 months, I was in a wheelchair. He refused to acknowledge that Anastrozole could have anything to do with my semi-crippled left knee. I waited from September until March before I could walk at all and, even now, I have to brace my left knee to do enough walking for the grocery store, for instance. My Illinois oncologist said, "You're just old" and refused to acknowledge that the A.I. drugs had anything to do with my semi-crippling. I now doctor with an oncologist at the University of Iowa, which means a 3-hour drive when in the Midwest, and I have a Texas oncologist, who got me the oncotype the Illinois oncologist refused to order. It was 29. I should have had 3 bouts of chemo according to my Texas oncologist, but 17 months passed before I got the oncotype that nearly everyone else I've spoken with got from the beginning. I had 33 radiation treatments, and I hope that will protect me, since my tumor was 95% estrogen dependent and the odds of a recurrence without Tamoxifen are 36% and with it for 5 years the odds drop to 18%. I tried Tamoxifen for 5 months, also, but that led to debilitating exhaustion and non-stop UTIs. I am off everything since Aug. 30, 2023 and praying that radiation did the trick. I also learned from 3 of my former employees whose mother went to the Illinois oncologist that they feel "He killed our Mom." How? Why? Refused to order any tests to confirm the recurrence that traveled to her pancreas. They tried to take her to the Mayo Clinic, but he said, "Why would you take her there. I interned there. I know everything they know." He blocked or prevented access to her tumor on ice and gave her heavy-duty chemo and she died in hospice. I had a terrible time with the Illinois oncologist and hope no one else ever has to suffer because of his indifference.

I can't with full confidence say why doctors prescribe Anastrozole before Exemestane. What I do know is that when one of my oncologists (I'm now on my 4th) prescribed Exemestane, my pharmacy (chain) did not carry it, had to call around to find it, and charge retail as my insurance Wellcare, did not cover it. I was able to find a GoodRX coupon to make the cost bearable. I recently discovered that the Mark Cuban drug site carries it at an affordable cost.