PR Low-Positive, should it be treated with Hormone Therapy?

2aT2N0M0ERHER2Pos

Hi All -

I can't find any info about this specific topic so thought to start a thread. I had 2 equivocal Her2 tests (IHC and FISH) my sample was sent to Michael Press an expert in CA and he tested with these outcomes:

ER - 75%

PR - 3%, low-positive

HER 2 Fish Ratio = 3.05

So technically by the book I am triple Positive. The AJCC states that any expression of 1% or higher is considered positive for PR. But my doctor says she will treat me as PR negative. I am questioning this because she also staged me 2A and if we go by the book the PR + interpretation would give me a prognostic stage of 1B. I hear there may be evidence that there can be benefit to hormone therapy for weekly positive (1-10%) results like my PR result of 3%.

Any insight or advise would be greatly appreciated!

Beesie

Because you are highly ER+, you will be prescribed hormone therapy. ER is much more critical to that decision than PR. There are no treatment differences for ER+/PR+ vs. ER+/PR-.

PR is more of a factor for those who are ER- and HER2-, because usually those with low PR are treated as though they are triple negative. This is where the question of whether or not to prescribe hormone therapy for those who are low PR comes into play.

As for Stage, that is something to discuss with your MO. It won't affect your treatment plan and really has no impact except on paper.

Hannah1962

I am ER+

Also low PR+ or PR- (depending on the lab)

and HER2 negative.

I was given hormone therapy. My doctor told me my oncotype was higher than it would have been had I been strongly PR+.

The staging is related to the cancer characteristics as well as the size, and perhaps your doctor's point (in the PR- comment) is he/she is increasing your stage designation slightly due to cancer characteristics. Don't worry though since the ER+ is a big deal and means the hormone therapy should be very effective for you. I know nothing about HER2 since I was negative.