Femara vs tamoxifen for gynecomastia

[jjpeabody]

Femara was suggested to prevent gynecomastia while taking casodex, however it seems tamoxifen is overwhelmingly referenced on this board. Can either of these drugs affect PSA lowering results of casodex, and is tamoxifen preferred and if so why. Thanks as always for your support.

[noahware]

It seems not just on this board but in the literature, in general, that tamoxifen has proven to be the most effective choice. But since its long term effects on health and/or its potential to interfere with other meds is not fully understood yet, many docs and patients refrain from using it.

My MO recommended radiation to prevent gynecomastia when I began 150 mg bicalutamide monotherapy a bit under a year ago, but had no problem prescribing 10 mg tamoxifen when I told him that was my preference. It seems to have done its job, but unfortunately the casodex just failed after bringing PSA from about 40 down to 3.9 (which will be the subject of its own post when I get around to it!).

Could it be the tamoxifen helped lead to earlier casodex failure, or a higher PSA nadir, than would have otherwise occurred it I had taken only casodex? I suppose it's possible. But I have not read a single thing in the literature where docs or researchers suspect that to be the case. Some say no interference occurs: ar.iiarjournals.org/content...

Other adverse effects associated with tamoxifen seem to be far more common in men with breast cancer, using it as a primary treatment, as opposed to its use in men with PC: onlinelibrary.wiley.com/doi...

[jjpeabody in reply to noahware]

Noahware, thank you for your timely and thoughtful reply and sharing personal experience. I will do the further research and bring up the use of tamoxifen with my oncologist. Best of luck and thanks again, Jim

[Mascouche in reply to noahware]

It might have been a blessing in disguise that bicalutamide 150mg stopped working for you. I read somewhere on this site that it can lead to neuroendocrinal cancer and that in the UK they no longer prescribe bicalutamide higher than 50mg.

[noahware in reply to Mascouche]

Not sure about the neuroendocrinal idea (I can't recall ever reading that), but a main reason it has fallen out of favor is that it can quickly turn from AR antagonist to AR agonist, and start feeding PC instead of fighting. (Which perhaps it did, with me.) And of course, the newer antiandrogens are better meds at what they do.

That fact that it failed was ultimately an expected outcome, but I was certainly hoping to get more than a year out of it. Waiting for it to wash out now, and hopefully (but not likely) get a little "antiandrogen withdrawal syndrome" effect before starting ADT.

Interestingly, the US was one of the few (maybe only?) countries that never approved bicalutamide 150 mg (or ANY dose) as a PC monotherapy, while 150 other countries did. So that remains an "off-label" use in the US.

[GP24]

These studies looked at using tamoxifen for gynecomastia:

pubmed.ncbi.nlm.nih.gov/163...

pubmed.ncbi.nlm.nih.gov/158...

pubmed.ncbi.nlm.nih.gov/156...

They do not mention Letrozol / Femara.

[jjpeabody in reply to GP24]

Thank you GP24 for being here and your knowledge replies. Your and Noahware's comments and references should answer my concerns and when I meet with my oncologist. Interesting post on estrogen therapy and Lupron by the way. Jim

[Tall_Allen]

Femara is a terrible idea because it reduces your estrogen to near zero. Without any estrogen, you will feel awful, and there may be other side effects. Men need a bit of estrogen. Tamoxifen replaces estrogen in peripheral tissue (like the breasts) but not in other tissue. Like estrogen, it has some activity against prostate cancer on its own. It has been used in many men taking Casodex to prevent gynecomastia.

[jjpeabody in reply to Tall_Allen]

Great! Thanks Tall_Allen.