Also, grade is subjective, according to my doc. I had results that read grade 2 at two hospitals, and grade 3 at another two.

There are other factors that make things complicated. My cancer is mixed ductal and lobular: the ductal part is HER2+. The HER2+ result from the biopsy probably meant the biopsy mainly got DCIS and ductal cells, but the surgical pathology got mixed ductal and lobular, so it was equivocal overall for HER2, until more testing showed a negative result because more cells were tested.

Lobular always has a score of 3 for tubular in the calculation of grade, which presumably increases my grade, since my tumor was half lobular.

The highish ki67% could be from cells healing after the biopsy (proliferation), and one doc agreed. I also wonder if the LVI is from the biopsy, meaning it could appear some cancer cells ended up in the lymph vessels (they were not in blood vessels) though doc said no recently when I asked.

I mainly questioned these things because of the disparate results but also to explain my low Oncotype. It would be nice to trust every result as an absolute truth and I don't mean to upset anyone!

In the end, the treatment recommendations did not change after the first post-mastectomy pathology. The first HER2+ result was from the biopsy so that mistake would not have persisted. While the three post mastectomy lab results were a little different, my treatment remained "just" letrozole, based on the Oncotype which we also have to trust! Getting opinions and pursuing extra tests just let me feel more comfortable but didn't actually change anything.