ER & PR - To Paul

[Chandi]

Hi Paul,

I am sorry to drag you again, anyway if you happend to get some information about ER & PR will you explain to us. I know about about ER but not very much about PR.
If you read my history given in my Thank uou message on 8th April, you will see my tumor contained more PR than ER.
Do the drug( Tamoxifen, Femara & Faslodex etc.), used to control ER stop PR also ?
Many thanks.
Chandi

[Paul]

Dear Chandi,

Research is on-going with respect to the nature of the progesterone receptor in the context of breast cancer. I have found very little reliable information on the topic of PR in the context of breast cancer. There is some thought that ER-negative, PR positive breast cancer has a poorer prognosis. I have seen a few preclinical studies relating to the PR receptor and the effect of progesterone on breast cancer, but the results are quite varied. There is some research in play that is looking at progesterone receptor inhibitors. I don't consider the available information all that informative given the lack of overall research results available.

ER-positive designation is generally considered a positive characteristic associated with breast cancer because drugs such as tamoxifen, aromatase inhibitors (e.g., Armidex, Femara, and Aromasin), and estrogen receptor down-regulators (e.g., Faslodex) may be used in an attempt to slow or stop cell proliferation by denying the cancer estrogen. As far as I know, these drugs only work as anti-estrogen treatments. The action of each class of anti-estrogen drug works differently.

It's not much Chandi, but I hope it helps.