here we go again: How inexact ER status testing is!!!

[Lani]

I have sent a lot of articles on to Jean on the relative merits of various antihormonal treatments for Her2+ER+ bc. Perhaps she can forward some on to you. Gotta go!

[Gerri]

My thanks to Hopeful and Becky for your responses (Lani I look forward to hearing back from you when you get a chance). From the link Hopeful provided it looks like the herception/tamoxifen combo is a good choice, but now that I am done with treatment and am only taking tamoxifen I need to make a decision. Becky, from your signature I know that you had an oomph so you could switch to an AI. What research did you base your decision on? I know my onc will go with what I want but I want to be able to support my position.

Thanks again everyone!

[Hopeful]

I have been looking for the paper I read that talked about one of the mechanisms for Tamoxifen resistance in Her2+ bc patients to give the citation. Apparently, in the lab (could have been in mice, not sure) they found that the ER receptor, normally located in the cell nucleus, was displaced to the outer surface of the cell by Her2 signaling. Apparently, the ER receptor has to be in the cell nucleus for Tamoxifen to work. Blocking the Her2 receptor with Herceptin caused the ER receptor to move back to the nucleus, where it belongs, and allowed the Tamoxifen to work. When I find this paper (as I am looking for another one, that's how it always happens) I will post the link.

Hopeful

[TSund]

Here's maybe a dumb question; does Tamoxifen work differently for POST-menopausal women?

Also, I've been pondering why hormonal positive tumors are MORE common in post-menopausal women. Has there been any determination on why that would be?

Is there any statistical trends different for er+ in menopausal women than post?

[Hopeful]

Terri,

The mechanism of action of Tamoxifen is the same in both pre- and post-menopausal women: it is a weaker form of estrogen than the body's own that competes for the estrogen receptor on the cell. One reason that pre-menopausal ER+ women are rx chemotherapy is to shut down the ovaries. This can be achieved hormonally or via their removal, however. When a woman's ovaries no longer produce estrogen, the body still requires it and a single enzyme converts aromatase into estrogen. Aromatase inhibitors prevent this action, and work via strictly estrogen deprivation - there is no circulating estrogen to attach to the receptor. AI's are thought to be more effective in treating Her2+ bc.

I don't know why ER+ tumors are more common in postmenopausal women, not do I recall reading a paper that addresses this. It seems counterintuitive, but there it is. I think if science could find an answer, we would be further along the road to prevention.

Here is a link to a terrific site with excellent information on all aspects of bc: http://home.earthlink.net/~ckane/brca.htm. There are lots of articles on hormonal therapy cited, one of them may even have those stats you are seeking.

Best of luck to your wife (and you!) with her treatment plan,

Hopeful

[TSund]

Hopeful,

You have great information. Thank-you! Shows hard work on your part.

I cannot remember if you were ER+PR+, but I am wondering what you know about the progesterone end of things. The fact that ER+/PR+ does better than ER+/PR- is another counter-intuitive for me. (if indeed progesterone is BAD for this type of bc) I read very little about the PR+ element, in fact many sources ONLY refer to ER+ without distinguishing between ER+/PR- and ER+/PR+

Are you familiar with Dr. Lee's books on natural progesterone? Much of what he says makes sense, (but rather rattling). If progesterone does work to eliminate estrogen dominance, than it seems to counter the advice on estrogen. Or just the lack-there of re: progesterone (NATURAL)

His bc book, however, says nothing on PR+ tumors one way or the other, at least that I can find.



TRS

[TSund]

Wow, if this is the way that Tamoxifen works, then it seems to fly in the face of advice about phytoestrogens; which are exactly that: very mild forms of estrogen. ...which I believe is why the belief they have protective elements re: breast cancer.

?????