Ki67 and Oncotype

My hospital does not do Ki-67. It is not used independently for any treatment decisions, but it is one of the 21 genes from the cancer cells that the Oncotype test includes in their assessment.

Robin, is your next appointment a follow-up with the surgeon? Whoever you see next, you should ask for a copy of the surgical pathology report - that may or may not include a Ki-67 figure. And you should ask if a tissue sample was sent for the Oncotype test. Because that assessment is done by Genomic Health, a 3rd party company, the results aren't included with the pathology report and take longer to get. Usually the Oncotype results will be reviewed with you by the Medical Oncologist, but the surgeon may know if the test has been ordered.

One addendum to the above. I don't recall how large your area of IDC was estimated to be. If in the final pathology it is less than 0.5cm, then an Oncotype test might not be ordered. The reliability of Oncotype results for very small tumors is questionable because so few small tumors were included in the Oncotype validity testing.

The Oncotype people don't need 5mm to do the testing - they can use a much smaller sample. And the final tumor size for staging combines what was removed in the biopsy and what was found during surgery. So if your total tumor size is larger than 5mm, Oncotype testing might be appropriate.

The way the Oncotype test works is that based on the genetic make-up of a tumor, an Oncotype score is assigned, and each score is associated with a recurrence risk and a particular benefit from chemo. The most recent and extensive research study that was used to determine these recurrence risk estimates, the TAILORx study, to my understanding included no tumors that were smaller than 5mm, and the average tumor size of participants was 1.75cm. So it is questionable (to say the least) to apply to a <5mm tumor a recurrence risk and chemo recommendation developed based on a 1.75 tumor. That's the reason why Oncotype testing is not recommended for small tumors.