Genetic testing for breast cancer Revised guidelines

Personalized ctDNA Testing and Late Recurrence in High-Risk HR-Positive, HER2-Negative Breast Cancer

@windyshores
I notice they mention the Ki-67 which my oncologist at Cleveland Clinic doesn't use. I may end up seeing an oncologist at Mayo in Jacksonville just to cover the bases.

I forgot to note the articles are from the Association for Clinical Oncology website. They have a lot of information about breast cancer news and newer tests and treatment protocols. And please post about your experience with genetic testing or new testing resources. Not all doctors are equally aware of the choices and new ones continue to be more precise for specific purposes. We need to become as informed as possible to be able to be proactive for our own health.

I had the Oncotype DX in early 2015, with a score of 8, and risk of recurrence at 6%, despite grade 2-3 (depending on lab), LVI, and ki67% of 20, just over the line for "high." The Oncotype includes ki67%, along with other proliferative factors. My ER was 95% and PR 80%.

In early 2020, after 5 years on letrozole, I sought out the Breast Cancer Index myself. My doctor had never heard of it. I am glad to see it is now in the guidelines. The BCI indicated no benefit from extended hormonal therapy, despite my original high score for ER. It also gave a risk, as I remember, of 5.7%. At that time, the BCI termed this "high risk" but they have since changed that method of classification.

I went a little further at the 5 year point of treatment and also did the Prosigna Assay (formerly PAM 50). That test had me with a higher risk of recurrence. I forget and don't have it with me but more like 9%? That made sense to me because without continued effective hormonal treatment, I thought risk might increase.

For both the BCI and Prosigna, I contacted the testing company myself and then gave the paperwork to my doctor. It seems that since they are now in the guidelines, patients might get them directly from the doctor.

I had a lot of discordance between seemingly very high risk pathology results and low Oncotype score. I was also originally told I was HER2+ after biopsy and had bought a wig for chemo. Then after surgery it was equivocal, then negative. I have mixed ductal and lobular and the ductal part is HER2+ but the overall score was, eventually, negative. I had a 4th opinion on this and that doc retested using more cells so I could feel reassured. From that, I would assume that my cancer was more lobular than ductal.

A few other things about my testing that I speculate on. Lobular always has a 3 for tubular so my grade 3 might be lower. My biopsy was healing and healing cells could account for highish ki67%. I still wonder if the LVI was also created by the biopsy though my doc says no. I put effort into pursuing answers because my genomic test was so different from the pathology. Basically, Oncotype Dx saved me from chemo! Seven years out and grateful so far.

I did get 4 opinions and that meant 4 different labs. They did vary on grade, between 2 and 3.

@callalloo my docs all said ki67% was unreliable and varied from lab to lab. I dealt with 4 labs and only one did ki67%. But that was 2015 so maybe it has been refined. Interesting to see it in the guidelines.

I so appreciate this information. I come from a wasteland when it comes to "awareness" (why I check into a cancer center in the city every year). I have been following the latest on the Association, especially since their last conference. As a Stage IIIc survivor this is important to me. Thank you!

This may be a very silly question but, does Oncotype testing apply to metastatic breast cancer patients? I mean, does it only tell you it's likelihood to recur?

I've had a drama on being HER2-negative and then another test showing HER2-positive (albeit very slightly). My treatment is now on HER2-negative. Also, it seems like there's some recent change of understanding on HER2 labeling (HER2 low) which may? affect the treatments for some people.
https://twitter.com/IlanaSchlam/status/1534149465841582084/photo/1

@eku The Oncotype is used at the time of diagnosis, and gives the risk of recurrence, so I don't think it would be used for metastatic breast cancer.

I also had HER2+ then equivocal then negative. But close to the line for positive. As I wrote above, it seems tje ductal part of my cancer was positive and the lobular part was negative. I am going to read what you posted about "low" HER2.

ps here is text on who can use the Oncotype: Oncotype DX helps predict the chance of metastasis and the likelihood of benefit from chemotherapy for early breast cancers that are all of the following [14,32-34]:

Tumor size smaller than 5 cm
ER-positive (and will be treated with hormone therapy)
HER2-negative
Lymph node-negative or 1-3 positive lymph nodes

First, I’m mightily impressed by your fierce self-advocacy and persistence. Second, your series of tests with often conflicting and/or equivocal results tell me (an overly anxious research nerd) that I made the right decision for me when I recently decided to forego the Oncotype.

For me, (and again only for me and women like me) such testing would have thrown up a wide, impenetrable barrier toward clear-cut, positive healing going forward. As someone with diagnosed osteoporosis, I’d already rejected AIs, and as a 71-year-old who works, travels the world and is entirely responsible for herself, I double-downed on no AIs and even no tamoxifen.

So it was radiation for me. I knew I wanted SOMETHING to bolster my lumpectomy, and I was told by my surgeon I did not require chemo due to the size and staging of my rice-sized tumor. And finally, something this gentle, pragmatic Hindu woman said resonated with me… “you don’t want to know what you don’t need to know.”

This is just me… lumpectomy last Friday, waiting on pathology results. Hoping/Planning for accelerated, partial breast radiation.

I had double mastectomy, no radiation, and did 5 years letrozole (Femara, brand name). My risk of recurrence was 6% with tamoxifen on the Oncotype, and 12% without. Odds slightly better with AI's. I didn't have many problems on Femara.

My only message to you is that there was a discrepancy between my pathology and the Oncotype. The pathology results were much worse. So it was reassuring. I would not have done chemo anyway.

I also had osteoporosis when I went on AI's. I lost density the first year and then it leveled off. I am now on Tymlos (started at low dose and moved up).

I actually wanted to avoid radiation the most!

You may be fine with your plan. If the pathology is scary then you can always do an Oncotype on the chance that it is better!

You can access these tests long term because the labs keep your specimens, I got to know all the lab staff at 4 hospitals and I moved the specimens around!

We need to keep going in pursuit of answers and plans until we feel it is right to stop. Sounds like you are there! Good luck!

Thank you for an important clarification… that you can access specimens for Oncotype testing later on, AND that testing may serve as a counterpoint to pathology results. We’re always learning on this journey!