Weird Oncotype Result

macdebbie

I had a lumpectomy on 9/14. The stereotactic biopsy that I had said the tumor was "at least" 3mm.

The final path report after surgery said the tumor was 3mm, and that the margins were clear. Both the BCS and RO said that the BCS got wide margins.

My MO did not go over the parameters of sending to Oncotype. I assumed it wouldn't even be a consideration for anything over 5mm, and even then my BCS said between 5mm - 10MM is questionable and the MO would likely have a long conversation before sending it.

So when the final path came back after surgery I called the MO's nurse and asked if he was going to send it, that I doubted it given the size. I never heard back what he was doing.

When I went for my post op appt on 10/5, he told me that he DID send Oncotype and that it came back as "too small a sample". Curious, I went today and got a copy of the Oncotype Report since he didn't give it to me.

Here's what it says: "Review of the H&E slide for this specimen indicated insufficient carcinoma. Please review this case and consider submitting a different sample that contains more tumor tissue. The preferred sample contains the greatest cross sectional tumor area. Refer to the Oncotype DX Pathology Guidelines for complete instructions."

I guess I don't understand how this could happen, because I don't know how all this works. Obviously there was a tumor that came out that was 3mm, otherwise how would the hospital pathology dept where I had my surgery have been able to do a report on it? I don't understand why that sample (the tumor) wasn't sent to Oncotype. How does that even work? Isn't there just one sample, and what happens when you send it out? Doesn't the hospital need to hang onto it?

Anyway, I guess bottom line what I wanted to know is should I even pursue this and ask him to send another sample or let it go since it's so small? I would imagine, but again, I don't know enough to say this, that the likelihood of a high Oncotype Score would be very low. I had no LN involvement, so it was staged at Stage 1A.

Beesie

macdebbie, just guessing here, but with all the tests necessary (ER,PR, HER2, grade, etc) and with the need to keep some of the breast cancer sample on file (I don't know if Oncotype return the slides), I would think that they were unable to send all the breast tissue slides that contained cancer cells to Genonic Health (the Oncotype company) - i.e. they couldn't send the entire 3mm. Note that in order to assess the cancer cells, the tumor must be spread out onto slides so that the cells can be viewed under a microscope. Keep in mind too that any slide with breast cancer cells may also include non-cancerous breast tissue cells. So your 3mm tumor was divided up into slides and they probably sent the best/largest sample they could but it was not large enough for Genomic Health to their assessment.

Genomic Health assess 21 genes within the cancer cells and I've heard that they require at minimum a good 3mm sample. This is probably why Oncotype testing is not usually done on tumors that are smaller than 5mm, and sometimes even slightly larger. Therefore the comment in your report "this specimen indicated insufficient carcinoma" was referring to the cells on the slides that Genomic Health received. That statement was not saying that you don't have cancer or that you have less than 3mm of cancer (recognizing that 3 mm is only 1/8th of an inch). They are referring to what they received.

I don't think you should pursue this. In addition to the sample being too small, even if it could be tested, the results would not be applicable to you because no tumors smaller than 5mm were included in the Oncotype clinical trials.

macdebbie

Beesie, thanks. That makes perfect sense now. I didn't even think that they had to split the tumor into multiple pieces.

I'm totally surprised he sent it. I don't get it. But I agree, it's not worth pursuing because of the reasons you mention. If the MO had talked to me, I would have told him NOT to send it.

On to radiation!

Beesie

Here are the NCCN treatment guidelines for your diagnosis; no Oncotype for tumors as small as yours. In fact if you look at the note I've highlighted at the bottom they are even saying no Oncotype for >5mm - 10mm tumors (T1b) that are grade 1 because TAILORx did not include any patients with this diagnosis in their sample. That was my MO's reason for not doing an Oncotype on my tumor - I had a T1b tumor that was "grade 1-2", i.e. right on the edge of grade 2, and with a mitosis of 1. Based on that, my MO said that he would not be comfortable that an Oncotype score and recurence score would be accurate for my diagnosis because virtually everyone in the TAILORx study would have had a larger and/or more aggressive tumor than mine.

macdebbie

Thanks Beesie!