With ER+ BC a high PR+ % is good.  Anti hormonals are more effective against these types of cancer.  The lower your PR is the higher your Oncotype score will be and more likely you'll need chemo.  I've not read of any research for an anti hormonal for PR.  

Doxie:  Can you explain a little bit more about why the PR+ is good?  I knew that ER+ was "good" because of Tamoxifen and AI's.  I'm very interested to know because I had a PR at 100% but was not eligible for Oncotype DX.  Thanks.  

The role of progesterone in breast cancer isn't very well understood from my research.  It does seem that having progesterone receptors is a good thing for prognosis, but I haven't been able to find a great explanation as to why.  The best I've found is that the presence of Progesterone Receptors indicates a functioning ER pathway (and therefore a target for tamoxifen) even in the absence of Estrogen Receptors.  I do know that Megace, which is an artificial progestin, is sometimes used as a treatment for advanced breast cancer that no longer responds to tamoxifen.  The description of Megace states that "it is not understood how it stops tumor growth, but it is assumed to interfere with estrogen". So it's interesting that a progestin is already given as a treatment, and now they're testing an anti-progesterone drug.  There is speculation that the synthetic progestins in some birth control (Mirena, Nuvaring, etc) increase breast cancer risk.  I'm sorry I'm not giving any answers, but this is something I've been wondering about for a while.  I do know that my progesterone level was quite low when I got pregnant with my second child almost 8 years ago and I exhibited signs of "estrogen dominance" for years before BC, but I don't know if it's related. I also wonder about the other hormones in our bodies that affect breast development and function - testosterone (they are finding Androgen Receptors in some BC), prolactin, oxytocin, etc.  I have a feeling that eventually they'll find there's more to this than ER/PR scores.

Thank you for raising this issue.  I've always wondered about the PR component.

I am new to this site and let's just say I am now becoming a member of this club. I have been diagnosed with ILC, grade 1, 13 mm, ER+ PR -.   I recently had a MRI and they possibly found another tumor 9 mm. I am hoping that it is a false positive. 

At any rate, the astonishing thing for me is women that initially had a 1cm tumor had a lumpectomy and shortly thereafter had a mastectomy. I am hoping for just a lumpectomy.  I am confused why there are so many mastectomies when the tumors are grade 1 and 1cm. Everything I have been told is that I have an excellent prognosis with just a lumpectomy but will require constant surveillance every 6 mos.

I would appreciate some input on this issue. Thank you.  

Johanne

Hi Johanne, location of the tumor(s) matters too. If there are more than one tumors and they are in different quadrants mastectomy may be in order even if the tumors are small. Surgeon needs to get clear margins.

Johanne--many women are frustrated or lack confidence in the surveillance methods.  My ILC was not picked up by mammogram.  Even when I found it, it did not appear clearly on the mammo.  Therefore, when I found out that even with what I had gone through, I would not qualify for an MRI routinely on the good breast, I took their strong advice to have a bilateral mastectomy.  I was not a candidate for lumpectomy due to tumor size, which started at about 7 cm.  But even in cases like those you've seen with much smaller tumors and lower stages, women just don't feel confidence with the current modes of detection, and in many cases rightfully so.

I did not receive the Oncotype DX test because I had a positive lymph node at diagnosis.  It is my understanding that the Oncotype can be used on any type of breast cancer that is not lymph node positive.  

 Just to clarify:  In my initial message I meant to say my doctor would have me under constant surveillance of my breast cancer every 6 mos for 5 years!!  

My mind has been a bit foggie these days..

Johanne

I believe that Oncotype has changed since 2011 to allow node positive patients, but I wonder if oncs are offering it.  I could not get it from my onc in September 2011.  

Regarding upping the progesterone, you really can't do that.  The PR+ % refers to how many of the receptors on the cancer cells were sensitive to progesterone.  There's no way to change that.  

Meow13 - it's remarkable how similar or dx is.  Moi - IDC 1.4 cm , Grade 3, 0/1 node, ER+ but barely PR (90% ER and 5% PR based on IHC) and Her2 negative.  Oncotype score 39.   The barely PR or negative PR with ER+ makes it luminal B, a bit more aggressive than luminal A breast cancer, but not as bad as a triple negative or her2+, though some would dispute her2+ being worse because there is herceptin for that.

It is curious that you didn't do chemo.  But I'm more curious why you say the cancer was a "slow growing one?"  My Ki67 (based on the biopsy) and a component in the Oncotype, was 60%, which indicates fast dividing cells.  Were you ever given your Ki67??

I've seen a lot of journal articles mentioning much lower % of chemo or hormone blockers working for Luminal B, so you may have picked right on the chemo, at least for that reason.

I had 70% er 6% pr and her2 negative. 6 nodes positive large tumor so no oncotype. I had to get chemo. No option there. No oncotype score but my ki-67 very low 9% and was a grade 2 My ki67 doesn't seem to correlate with a poorer prognosis. I did have the mirena removed a year before my breast cancer diagnosis. Funny that I had low pr after having the mirena for 6 years.

To lower my recurrency- I had full hysterectomy ( I am not brca positive) , take Metformin and zometa and arimidex. I am 44. Honestly- I have no idea what the numbers truly mean and figure I have done everything I possibly could to prevent it from coming back.

The benefits of being high PR+ is somewhat counterintuitive. Actually the higher the PR+ % generally the better the prognosis. Tamoxifen is not as effective with low PR % tumors, thus women are encouraged to take AIs and if necessary with ovarian suppression. Tumors with ER+, low PR, and high Ki67 are Luminal B. Generally chemo is suggested for these and there is a poor prognosis.

Somewhere on these boards there was a discussion on PR blocking drugs. Not sure where it is, but it may have been within the last 6 months or so.