ER/PR Questions

DianneS · 11-14-2008, 11:06 PM

I am still unclear about the significance of having ER+ versus ER- and PR+ versus PR-.

Or, having ER or PR be positive and the other negative.

Has one or the other been linked to recurrence?

I am weakly ER+. Would I get Tamoxifen?

Thanks, ladies.

Diannes

Becky · 11-15-2008, 07:18 AM

The significance of being hormone positive is several fold. One is that there are drugs like Tamoxifen or Aromatase inhibitors to combat it (like there is Herceptin and Tykerb to combat Her2). Secondly, being hormone positive (even if also Her2+) tends to correlate to a slower growing (hence less aggressive) disease.

It is rarer to only be positive for one of the hormones but I am only ER+ but PR neg. It is very, very rare to be PR+ but ER neg. Drugs like Tamoxifen seem not to work well unless you are positive for both receptors (and in some studies - highly positive for both receptors). Aromatase inhibitors tend to work better for women who are only estrogen positive or weakly positive. You will need to talk to your doctor about this.

You should also get tested to see if you are a Tamoxifen metabolizer or not as well. If you cannot metabolize it, it will not do its job for you.

Because I was not postmenopausal but I was PR neg, I got an ooph so I could take an aromatase inhibitor. This was my decision and it might not be the right one for everyone. You need to consider your choices and discuss this with your doctor. There are other ways of shutting down the estrogen to take an aromatase inhibitor if that is your choice (like Lupron or Zoladex shots).

I don't know your age either. If you are already postmenopausal, then you have all the options without having to worry about the ovaries.

Have a nice weekend.

DianneS · 11-15-2008, 09:12 PM

Hi Becky,

I am 55 and had my uterus removed 10 years ago due to fibroids and my ovaries/fallopian tubes removed because of a benign cyst just this Feb. 08. That was before I found out about the breast ca in Aug of this year. So I am in menopause -altho I never got hot flashes until a few years ago. After the ooph my body went nuts but I think it's settling down to life without ovaries. I still get hot flashes several times a week, more if I'm under stress, like now.

I am 'weakly positive' for ER - and PR neg -anyone here who has been placed on Tamoxifen or something else who is also not a strong ER positive?

Is that a poorer prognosis, being weakly ER positive?

I will ask my doc about the Tamoxifen metabolizer when I see her Tues. I think right now she is concerned about getting me started on chemo; hopefully the Taxotere or some other drug in that family will work for me this time.

Thanks for your reply, Becky. I learn so much on this forum.

Diannes

dlaxague · 11-16-2008, 09:16 AM

I am 'weakly positive' for ER - and PR neg -anyone here who has been placed on Tamoxifen or something else who is also not a strong ER positive?

Yes. I took arimidex for two years for a result of 5% ER positive. I questioned taking it at the time, for so low a value, and was told that it was then (2001) becoming standard of care to treat any degree of ER positivity.

Then I had the pathology re-done at Baylor and it was completely negative so I stopped the arimidex. I sure wished that I'd had it re-tested sooner. Before making your decision, I hope that you'll request a second pathology opinion at a comprehensive cancer center. It's easy - you just sign a consent and send your tissue blocks and slides off (or have them sent). I found the information about how to do that on the Baylor website. But your onc or pathologist probably knows, also.

In general (but not always), it is thought that the higher the ER, the less aggressive the cancer, and also the more responsive it is to hormonal treatment. They now know that there is at least one subset of ER+ cancer that is more aggressive and more resistant to hormone treatment, so it's not crystal-clear.

Since you are menopausal without ovaries, if it does turn out that your cancer is ER+, you may be advised to take an AI rather than Tamoxifen. In which case you won't need to concern yourself with the test for Tamoxifen metabolization. But as you say, chemo first - plenty of time to sort out the ER questions.

Debbie Laxague