once again, ER+her2+ breast cancer is found to behave differently than ER-her2+

[carolanno]

Thanks a lot, Lani. I'm new to the forum so I'll look at some of your older posts on this topic. So I guess this means that estrogen emerged as a stronger growth factor for my cancer cells after being dormant for 10 years. Even though it appears that my cells are at least partially resistant to Herceptin, my onc. says there is evidence that it can still be effective w/another chemo agent (Navelbine). I will consider an AI after that, but at 54 already have severe osteoporosis in lumbar spine so I'm not too keen on that idea...I had been trying to avoid osteoporosis drugs...
I'm so grateful to have this forum and access to people like you who are so knowledgeable and up on the latest research. Are you trained in the medical/research field?

[Lani]

A friend of mine who is a librarian in Denmark asks how I find all this stuff--
and tells me I should have been a librarian!

Lizbeth-- progestins and progesterone are two different things. The former has been shown , especially in combination with estrogen to predispose some to breast cancer.

I have seen a poster presentation from a researcher at UCLA five years ago or so @ ASCO or AACR showing an antiprogesterone, RU486 (controversial in US because of its use as a morning after pill) is synergistic with herceptin in the lab/petri dish setting.

I really don't think anyone understands all this, but they are working towards it.

How old are you? DId you have chemo and what was its effects on your periods? Are you on/have you been on Tamoxifen? Have you had a pelvic ultrasound to see how thick your endometrial lining of your uterus is? I am sure your doctor asked you all of these-- perhaps you could ask him if there is any other alternative ie, IUD without the progesterone ? I have no idea and am not qualified to even be commenting on any of this but perhaps I can help you formulate your questions.

Hope this helped