Percent of Tumor vs Percent of cells

Does anyone know:

This might sound kind of dumb, but after reading a previous post I thought about this:

When we are described as ER % positive - does that mean a percentage of the tumor is positive or percentage of every cell is positive?

for example: If I were ER 5% positive; Is 95% of the tumor ER negative or are the cancer cells themselves 95% ER negative.

Thanks!
Maria

Hope this helps.


The results of specific molecular tests on your cancer cells may play a significant role in determining treatment and prognosis. For example, breast cancer is often treated differently depending on whether the cancer cells are found to be Estrogen Receptor Positive (ER+) or Negative (ER-). ER+ cells have receptors for estrogen on their surface, and their growth often requires the presence of estrogen. ER+ tumors are more affected by hormonal treatment and tend to be less aggressive.


Regards
Joe

Joe

Does this mean that if you are hormone positive and Her 2 positive that it is less aggressive than just being Her 2 positive and hormone negative.

I had heard that no matter what, it was always good to be hormone positive as well.

Thanks in advance

Becky

I have always been a little perplexed with this positive/negative thing.

I have heard exactly what you said but just wonder on the opposite side of the coin, if one is estrogen negative (which I am) why is this not a good thing since I assume that our tumors are not effected by any estrogen present. But, we still have to be careful with estrogen.

Has always confused me.

Irene

OK, I will my confusion too. Is er/pr+ "better" because of the general makeup of the cell, or is it because we have the opportunity to take tamoxifen/AIs?

Maria:

Here is an explanation of the hormone receptor test from breastcancer.org:

"the number of cells that have receptors out of 100 cells tested. You will see a number between 0% (no receptors) and 100% (all have receptors)."

I think being receptor positive is a good thing because you will be able to use hormonal treatment as another weapon.

Hope this helps,

Linda