Her2 Equivocal results

That's very common. They usually send it back for the FISH test, which takes a bit longer but should result in an answer.

amica - an equivocal result should automatically cause what is called "reflex" testing, meaning that when initial IHC testing yields an unclear result an additional test with FISH (more expensive, but more accurate) is automatically run that provides a clear result. Most labs use an IHC based testing process because it is less expensive, but I believe about 1 out of every five IHC tests that register positive for a level of Her2+ overexpression will result in a 2+ for Her2, which shows incomplete staining or weak staining, but occurs in at least 10% of cells, and prompts a re-test with another testing platform.

I had IHC equivocal, then Fish also equivocal, then IHC and that was +3. The final decision was stated as:

INTERPRETATION: Immunohistochemistry is positive (3+) for over expression of
the Her-2/neu oncogene protein.

RESULTS: There is 3+ membranous staining of the invasive tumor cells present
on the slide (Surg. Path. LS17-1591, block A1).

Comment: The immunohistochemistry demonstrates strong membranous staining in
greater than 10% of the tumor cells, consistent with a 3+ according to the
2013 ASCO/CAP guidelines. The equivocal FISH result is noted. The
immunohistochemistry was also reviewed by Drs. Dhananjay Chitale and Nilesh
Gupta who agree with the diagnosis.

I had this redone at another lab and they also came to the conclusion it was +3. But it took 30 more days to complete. The biopsy was done March 13 and the final decision was not completed until June 27. My MO still doesn't believe the final result but is treating me as Her2+. So the Herceptin and perjeta were added in at my 3rd cycle of chemo.

My surgical specimens were tainted because I was prescribed neoadjuvant arimedex.

The consensus is that my tumor was heterogeneous and more than 1 type of cancer within the same tumor. That was the reason he did not trust the onca scores.

Hi Amica,

My biopsy specimen came back as HER2 equivocal in both IHC and FISH.

My specimen was subsequently tested at a well known NCI teaching institution and the results are as follows;

“According to the updated CAP/ASCO Guidelines for Interpretation of HER-2 Testing of May 30, 2018, an IHC diagnosis, followed by a FISH ratio of less than 2, but with more than 4 signals of HER2 DNA per cell requires a repeat count. If the repeat count is the same, the final results is considered negative. In this particular case, there is documentation from the original Integrated Oncology Report (AGF18-1136) that three observers counted the signals. It is uncertain whether patients with an average of greater than 4 and less than 6 HER-2 signals per cell and a ratio of less than 2 benefit from HER-2 targeted therapy in the absence of 3+ IHC. If the specimen test result is close to the FISH ratio threshold for positive, there is a higher likelihood that the repeat testing will result in different results by chance alone. Therefore, when IHC results are not 3+ positive, it is recommended that the sample be considered HER-2 negative without additional testing on the same specimen. In this case, it is noted that the ratio was 1.5, not close to the threshold for positive result. In this case, it may be helpful to repeat HER-2 testing on the excised specimen, which is likely to provide a greater sample of tumor cells for HER-2 testing. Of note, the updated guidelines were made available after the initial HER-2 result of "equivocal" was provided for this patient.”

So as of now, I am being treated as HER2-. We will see what happens after surgical excision.

Hope this information is helpful.

Hi dear Amica!

Just checking in and counting down the days until the 9th! Not too far off now. How did you learn about the Her2 potential? People here have given you great info. I had two equivocals before my Fish. I had an amazing MO stay on it like a dog. I started out in a clinical trial that turned out I couldn't do due to subtype, but even they didn't keep hunting the Her2 down. They did, however, do a Mammaprint which came back high risk, which is why my MO stayed on the testing as she was sure it was because I was Her2+. So this kind of thing happens often.

How are you doing? Did you get out and see some nature this week? Are you getting sleep? I know this countdown to the first doctor's visit post biopsy is exhausting. I wish they could put a Pet scan on the calendar before you see them on the 9th. So much waiting. Any changes in the physical sensations around your neck and collarbone?

I send much love and good spirit!

Hi dear Amica,

Thanks so much for the warm response! It is hot hot here today. In the 90's. Oh my, California is burning up. We haven't even reached our fire season down here around San Diego and by October we will be in our dangerous windy time. But for now we have oddly warm ocean temps. They measured the temp at 81 in La Jolla and the average for this time of year is 69! Wow. I did indeed get in the water. It feels amazing. I had to stay out for 8 days after my port removal so getting back in this weekend was a total treat. I've just been body surfing and getting my shoulders to move again. The port removal went as beautifully as I could hope for. The lymphadema is a bother, and it flare a bit with a good workout, but what are you going to do?! I say the same thing when someone puts a piece of pie in front of me... my stomach will flare, but whatcha gonna do? :O.

Funny, my husband and I are also listening to Anna Karenina! But not with Maggie Gyllenhal . The reader is lovely though. I space out a lot while listening, but my husband is patient and fills me in. I am glad you are sleeping, even with that pain and swelling you have going on! I hope that this week it calms down even more. Is it all primarily on one side? And you probably can't sleep on that side either now. I am currently in love with Naprosyn as my favorite pain killer. Too bad you can't take it all the time.

Your appointment week is finally here. I am praying they don't do much more hurry up and wait stuff and the ball begins to roll faster!

Alright my friend, thinking of you with much love and hope. Fingers crossed for intelligence and compassion beautifully directed to you on Thursday!

carmstr835: It looks like I have a heterogenous, IDC high grade, tubular, 1.8cm at 12 oclock and a DCIS high grade, with focal necrosis. Not staged yet. my core biopsy was er positive 100%, pr posiyive, and HER2 2+. I think my staging will be IIA, but what do I know? So why would you dr. not want to treat based on the ISH testing results at 3 of the HER2? why treat as if it is not positive for Her2? just curious. first time cancer. 59yrs old. one breast.