study: Tamoxifen-resistant breast cancer reversed

new_direction

http://www.sciencedaily.com/releases/2014/06/140613084502.htm

Bounce

How is it possible to tell if the cancer is Tamoxifen resistant in people (not mice) before they relapse/progress?

MusicLover

Thank you for posting this.  I wonder if they are referring to stage IV patients, that's how resistance can be noted.  Hopefully they will do more testing on this and determine an approximate timeframe for this combination to be a viable therapy.

new_direction

bounce - i am interested in that as well. I don't understand why it's not possible to "test" for resistance before starting treatment. Maybe it just seems more easy than it is but i cannot help thinking "the less we know the more women we have to treat"...

floaton

New direction, I agree.  I've often wondered in the last few months if my tumor was/is(?) tamoxifen resistant, and if there is a way to know, since my grade was 3 and I was PR positive but <10%, so by some definitions I'm luminal B, which from what I've read I think is more likely to be tamoxifen resistant?  It's frustrating to think I may be spending all this energy tolerating side effects from a med that may not even be working.  

Lojo

I think the issue is 1) this was in mice injected with cell lines that were known to be tamox resistant 2) If I am thinking about this correctly, the only way to learn whether a particular tumor is tamox resistant other than tamoxifen failing and new tumors growing, is to sample a tumor, grow the cells in a petri dish, and see whether it responds to tamoxifen. The problem is for non stage 4 people, there aren't any tumors to test after initial treatment, just (possibly) stray tumor cells floating around. So, they'd need to develop some sort of test to isolate stray tumor cells, culture them and test for tamox resistance (or develop another biomarker test for tam-resistance). Right?

Or just give everyone this new drug in hopes that it catches the tam-resistant cells.

new_direction

why can't tests be done on the primary tumor or biopsy.