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.