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

[Gerri]

Lani,

Thank you once again for posting. I am still in the learning curve of reading abstracts/articles and just want to clarify the statement below taken from the conclusion of the article you posted.


"Tamoxifen is likely to remain an important chemopreventive agent, particularly in the premenopausal setting. Thus, this hypothesis may help us to consider other combinations of agents for prevention, such as combinations of tamoxifen with small molecule inhibitors that target the EGFR family or novel receptor tyrosine kinases. More importantly, it should encourage the design of prevention interventions in a setting where we can follow biomarkers and prospectively test the hypothesis presented in this paper."

To me this is verification that Tamoxifen is still a viable agent for those of us who are premenopausal HER2+ and ER+. Does this apply to those of us already diagnosed with bc or only as a preventative in the high risk population of possibly developing bc?


I am currently on Tamoxifen and was confused about whether it is appropriate for HER2+ bc. I am still premenopausal (age 53) and have been wondering whether I should push for suppresion of my ovaries so I can switch to an AI. My onc doesn't feel there is enough data to support this yet but has left the decision up to me. If my interpretation of the article is incorrect can you guide me to research that supports switching to an AI?


I really appreciate the time you take to help out those of us who are not as skilled in interpreting the results of the research out there. I am very interested in learning how to search for articles and how to to effectively interpret them. Any suggestions of how to hone those skills?


Thanks again,

[Lani]

sorry

more soon, I hope!

[Hopeful]

Gerri,

Here is a paper that may interest you: Synergistic Interactions between Tamoxifen and Trastuzumab (Herceptin) http://clincancerres.aacrjournals.or...full/10/4/1409

The conclusion reached is, in the lab at least, this is an effective combination.

Hope this helps,

Hopeful

[TSund]

I've always heard that AI's were better for HER2 but that might have been before they were treating early bc with Herceptin, and therefore the HER2 was causing Tamoxifen resistance?

I'm confused as to which is going to be better for pre-menopausal (Ruth).

It's possible she'll be thrown into permament menopause by TCH, but possible not also. She has late menopause in her genes. If she goes AI, then we have to go ovary suppression by drugs or ooph. I know that Tamoixfen is much better for the bones (but harder on the heart?)

Comments?

[Becky]

http://breast-cancer-research.com/co.../1/R4/abstract

I knew I would eventually find the article on the small study (only 10 women) in which use of Herceptin changed their bc from ER neg to ER pos (therefore, they then benefited from antihormonal therapy).

[Becky]

Terri

I believe that while on Herceptin, tamoxifen is fine but it is not fine if it is used as a single treatment (blocking just the estrogen receptor but leaving the Her2 receptor open and exposed).

After Herceptin is concluded, Faslodex or an AI should be used as Tamoxifen resistance (really doesn't mean that it doesn't work but that another pathway is being employed to make the cancer grow. In our case, Her2 or something else) can occur.

Secondly, there is a fine trial that looked at metastatic women that were ER+ and Her2+. None of the women had been treated yet with anything. Half the women received Arimidex and the other half received Arimidex and Herceptin. The half that got Arimidex and Herceptin didn't have progression for 2 years (versus 9 months with Arimidex only). This convinced me to get my ooph AND helped me convince my onc for 5 extra treatments to keep me on the combo for a full year.

[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