HER2++++ definition

MCS · 03-14-2006, 07:56 PM

HI everyone,

Is there a difference between HER 2 + and HER2 ++++.

My onc only explained that HER 2 is an amplification of existence of the protein. He did not explain difference.

Would this show up on the path report?

Thank you

MCS (Maria)

AlaskaAngel · 03-14-2006, 08:51 PM

Maria,

There are 4 "HER's" (HER1, HER2, HER3, HER4) and people with breast cancer can have more than one of them at the same time.

That is completely different from the +'s. There is no such thing as HER++++, only HER2+, HER2++, or HER2+++. The plusses tell us just how strongly HER2 a cancer is. HER2+++ means very strongly HER2 positive.

A.A.

katcdale@yahoo.com · 03-23-2006, 10:20 PM

There are 2 tests for the Her2 protein, I thought,--
The ICH which uses the human eye to see how much is stained, little, some2+, alot of staining 3+.
Then ther is the more accurate test-FISH, which letters stand for words. You may even get a false positive (2%) with the ICH, but its usually correct with a 3+. You need to have your pathologist make sure you are FISH Positive before yrs of Herceptin are started--My surgeon said. Kat in the delta

saleboat · 03-24-2006, 08:43 AM

Hi! There's lots of confusion about the IHC and FSH tests, and an acknolwedged need by the medical community to develop a better method by which to measure Her2 in light of the rapid advances in treating this type of cancer.

Until then, I believe that we need to be very accurate when we discuss testing for Her2. It is true that the FSH test is more accurate, however, when compared to IHC, to say that FSH is more accurate than IHC is comparing apples to oranges.

The IHC test measures the amount of HER2 on the outside of the cancer cell. The FSH test measures the expression of HER2 inside the cancer cell. (To simplify it greatly).

Herceptin is appropriate for patients who are HER2 postive by IHC 3+, but FSH negative. I have researched this, because this was the pathology of my cancer. I am a stickler on this because God-forbid that someone that could benefit from Herceptin not get it due to a testing error or omission. It is true that IHC can have more false positives than the FSH-- so it is important to have these pathology tests done by experienced, high-volume labs.

Here is an article from this site which provides more background on the two tests, and patient responses to chemo + Herceptin.

http://www.labcorp.com/clinicaltrials/what/HER2.pdf

Jen