AI's, etc effect on estradiol

[TSund]

Question,

Has there been clear differentiation made on how the various AI's and tamoxifen target the various kinds of estrogen? In particular, targeting estradiol, which I believe is the most dangerous estrogen. While doing a google search I was shocked to see loads of body-building forums talking at great length about taking estrogen suppressing drugs; the exact same drugs bc patients take: tamoxifen, arimidex, aromasin, etc. While I know this is an EXTREMELY dubious souce of info, and I am appalled at what these people do for vanity, one post impied that aromasin was more effective at lowering estradiol than arimidex, which he/she claimed more targeted estrone. (these crazy people are doing bloodwork on a very frequent basis) I am interested if there is any scientific validity in this statement.

Thanks

TRS

[Margerie]

Did you see the movie The Wrestler?? I was shocked to see a scene where he buys Arimidex on the black market.

As far as estradiol and AI's, I am sure there are lots of studies. I do my own study by having my onc check my estradiol level when I get my routine bloodwork done every few months. It varies between 4-8 ng/ml otherwise known as "in the toilet." I have been on Arimidex for almost 4 years.

[TSund]

Haven't seen it Margerie. This whole scene shocked me...but it also shocked me how much information we DON'T seem to have regarding the more specific details of these drugs.

Has there been a comparision between Aromasin and Arimidez for non-metastatic HER2+ bc?

And, if there is a difference between one of these and the other, might it not correlate to its efficiency of attack on the "bad" estrogens?

[Becky]

There is a trial (started about 4 yrs ago) studying 5 yrs of Arimidex vs Femara vs Aromosin. My cousin is in this trial (Arimidex arm) so there won't be alot of results for awhile AND IMHO, it is the sustained results that will be the most interesting as all 3 drugs do a great job in reducing circulating estrogen. It is how well you do after therapy concludes that is very important (much the same as chemotherapy outcomes).

I would not spend alot of time pondering the minute differences in these drugs but rather focus on quality of life. Are there debilatating side effects that may force a change so one does not experience severe joint pain etc. If you are on one drug and are feeling good, great! If not, change.

[TSund]

I am interested in the sustained side effects vs efficacy also. I know you've been doing very well, but it seems so many are really suffering with these AI drugs. We met a woman on our recent cruise who had given up on the Armidex; the joint difficulties were making her hands unusable. Her doc moved her to Aromasin, there seems to be less joint issues there, but I am concerned with the longer lasting issues that could ensue as Aromasin works so differently that Arimidex on the Estrogen receptors.

Ruth is supposed to be switched to AI within the next couple months. I'd like to get a feel for which AI is going to give her the least problems short run, long run, and of course which will be the most effective at keeping cancer at bay.

[Becky]

I think that you need to start one and see if you can tolerate it. In trials on metastatic disease, it has been shown that they think Femara might be the most effective. That said, try that and if Ruth has so many problems that she is almost a cripple, switch to another as that many times solves the problem. It is better to be on something (even if in the future it is proved to not be the most effective drug (by a small percent)) than to not be on anything.

When I began, Arimidex was the only one out of trial AND I don't get the joint side effects from it so I am not taking any chances by switching even though some studies are pointing that Femara might be alittle more effective.

In the metastatic setting, Femara was more effective but not statistically and only in small (less than 12 women) studies. In all, I feel that they are all similarly effective and there is no doubt that they are more effective than Tamoxifen in postmenopausal women.

[TSund]

Thanks for your kind reply Becky. :)

I suspect that the efficacy of Femara and Arimidex are very similar as their mechanism is very similar. It is interesting, tho, that there is a distinction between the two for side effects for various folk. Armomasin is a whole different deal, and I cannot find much literature to compare it to the other two.

Ruth's onc decided to wait another few months for the switch as Ruth's hormone tests were inconclusive early on, and she was on such a regular menstruation cycle before she entered chemo.

I am meanwhile trying to scout as much info as possible regarding the choices.