Is my PR-negative breast cancer a bad prognostic marker?

Question

Hello doctor,

I was diagnosed with stage 3C IDC, Grade 3, Ki 67 Score 30 to 35 %, ER/PR positive breast cancer with multiple lymph nodes involved in the axilla, intramammary, and one in the supraclavicular area. I took 4 DD AC plus 12 Paclitaxel chemotherapy as neoadjuvant therapy.

My initial lymph node in the axilla was 1.81 inches, and the tumor was about 1.88 inches. Then, surgery was completed; before surgery, a PET scan was repeated, which showed a complete metabolic response to chemotherapy.

The pathology report showed three lymph nodes with macrometastases, extensive lymphovascular invasion, and 0.98 inches of tumor. The nodes had a maximum 11 mm deposit and a tumor at 0.98 inches, invasive cancer, and it was grade 2. I asked them to run the pathology report for biomarkers, and now it shows ER positive, PR negative, and HER2 positive, with Ki67 at eight to ten percent.

My questions regarding my condition are:

What is the implication of positive PR to negative PR post-chemotherapy? I read the research that said it is a bad prognostic marker. Is that true?
Is a low Ki67 score post-chemo a good indicator of longer survival outcomes
How much is the role of progesterone in outcomes, and what are the next steps?

Kindly help.

Thank you.

Answer 1

Hello.

Welcome to icliniq.com

I can understand your concern.

It looks like stage 3C breast cancer. The good things are that it is HER2-negative and ER (estrogen receptor)-positive, and it has responded well to chemotherapy. The concerning thing is that lymph nodes were favorable pre-treatment, and PR (progesterone receptor) switched from positive to negative.

It would have been worse if both estrogen and progesterone receptors had changed. However, since only a PR switch is involved, less is known about the outcome and its impacts on prognosis. I suggest rechecking the status of these receptors at another laboratory.

But certainly, it is a little concerning that it switched from positive to negative. Progesterone negativity, high-grade tumors, and poorly differentiated tumors will have little impact on responsiveness to hormonal treatment, as they respond a little less to hormonal therapy compared with breast tumors having both receptors, ER and PR positive. If progesterone is in the postmenopausal phase, the response to hormonal treatment is usually excellent.

Regarding another issue, low Ki-67 (monoclonal antibody, cell division marker) post-chemotherapy is a good indicator of a good response to chemotherapy.

I hope this is helpful.

Answer 2

Hello,

Welcome back to icliniq.com

I understand your concern and will try to help you.

Estrogen is a more critical marker for hormonal treatment and prognosis, and your ER (estrogen receptor) is strongly positive. This is a good marker for hormone response, as some breast cancers are weak ER-positive. Postmenopausal status with estrogen receptor positivity usually responds well to hormonal therapy, but progesterone receptor negativity will reduce the response a little bit in some cases.

However, hormonal treatment plus Abemaciclib is an excellent combination for disease-free and overall survival.

I hope this helps.

Thank you.