HER2 Support Group Forums - View Single Post - Opinions welcome-- do I get a fourth opinion on hormonal treatments?

Becky · 05-16-2006, 08:14 PM

I am not sure that tamoxifen works better than an AI in strongly positive ER/PR cancer. It has been proven that AIs work better. It just that when you compare studies of:

1. tamoxifen in ER/PR+ vs ER+/PR- - the women who are positive for both do better. However, the probability that the women who are PR- are probably also Her2+ or positive for another Her pathway is most likely high. Therefore, do they do worse because of tamoxifen resistance (really just cross signaling) or because if they were just ER+, it doesn't work as well. My opinion on this is that if a ER+/PR- woman took tamoxifen and she was only that and not Her2+ or Her1+ or anything else, tamoxifen should work just as well as it does in a ER/PR + woman.

2. comparing AIs in the same population as above. There was only one study that compared Arimidex to ER/PR+ women to ER+/PR- women. It would make sense that Arimidex might be more beneficial in a woman that is only ER+ as AIs disrupt estrogen manufacture in the adrenals and fat cells. Currently, there is no known disruption of progesterone.

That said, it is also well known that being PR+ only (and ER-) is not enough for a true cancer to occur. Known literature states that PR will cause a cell to grow (in size and to maturity) but it cannot, by itself, cause it to reproduce uncontrollably. Therefore, one has to assume that a woman who is PR+ but ER- has another driver for uncontrolled cell division. For some of us who may be PR+ but ER-, we know that driver is Her2. For others, it is Her 1 or 3 or other things not measured or discovered yet.

Also, being + for PR is supposed to be a good progostic factor but I really don't think enough research has been done on the PR to truly determine its related function to breast cancer and the determination of its early loss when the Her pathway is involved (as many at least maintain higher ER+ levels than PR+ levels in Her2 disease).

I think anyone who is highly ER/PR needs to be on an antihormonal regardless of Her pathway status. What needs to be assessed is which ones are the best ones to be on and more work needs to be done in this area for premenopausal women who are also Her2+ (especially if they are not highly positive and have lost the positive nature of the progesterone receptor).

Sorry this is so longggg.

Kind regards

Becky

05-16-2006, 08:14 PM	#22
Becky Senior Member Join Date: Sep 2005 Location: Stockton, NJ Posts: 4,179	Hi Angel I am not sure that tamoxifen works better than an AI in strongly positive ER/PR cancer. It has been proven that AIs work better. It just that when you compare studies of: 1. tamoxifen in ER/PR+ vs ER+/PR- - the women who are positive for both do better. However, the probability that the women who are PR- are probably also Her2+ or positive for another Her pathway is most likely high. Therefore, do they do worse because of tamoxifen resistance (really just cross signaling) or because if they were just ER+, it doesn't work as well. My opinion on this is that if a ER+/PR- woman took tamoxifen and she was only that and not Her2+ or Her1+ or anything else, tamoxifen should work just as well as it does in a ER/PR + woman. 2. comparing AIs in the same population as above. There was only one study that compared Arimidex to ER/PR+ women to ER+/PR- women. It would make sense that Arimidex might be more beneficial in a woman that is only ER+ as AIs disrupt estrogen manufacture in the adrenals and fat cells. Currently, there is no known disruption of progesterone. That said, it is also well known that being PR+ only (and ER-) is not enough for a true cancer to occur. Known literature states that PR will cause a cell to grow (in size and to maturity) but it cannot, by itself, cause it to reproduce uncontrollably. Therefore, one has to assume that a woman who is PR+ but ER- has another driver for uncontrolled cell division. For some of us who may be PR+ but ER-, we know that driver is Her2. For others, it is Her 1 or 3 or other things not measured or discovered yet. Also, being + for PR is supposed to be a good progostic factor but I really don't think enough research has been done on the PR to truly determine its related function to breast cancer and the determination of its early loss when the Her pathway is involved (as many at least maintain higher ER+ levels than PR+ levels in Her2 disease). I think anyone who is highly ER/PR needs to be on an antihormonal regardless of Her pathway status. What needs to be assessed is which ones are the best ones to be on and more work needs to be done in this area for premenopausal women who are also Her2+ (especially if they are not highly positive and have lost the positive nature of the progesterone receptor). Sorry this is so longggg. Kind regards Becky