Different results clarified
 

Quick recap - I had an HER2 test done in Feb by the Royal Marsden Hospital, London. It was negative, I was unaware of it at the time. I pressed my local oncologist to do a test in October which she reluctantly agreed to and it came back positive. She said she could not recommend Hercpetin in my case. I contacted the Royal Marsden for a second opinion and that is when I found out that a test had been done in Feb and was negative. After a lot of going backwards and forwards the Marsden have repeated the test and come back today with the result that it is negative.

I now have 3 tests results, one positive and two negative. I know I should be relieved that I am probably negative - but I still wonder in the back of my mind which of the results are right.

The Royal Marsden intially just did IHC test and it came back IHC1+

My local oncologist did IHC test and it came back 3+

The Royal Marsden have now done Fish test and it has come back negative.

Can I really believe this negative result?

I feel guilty too - so many people know they are positive and are dealing with it and I an whingeing on as even though I have negative results I am not happy. I should be breaking out the champagne - having believed and accepted that I was positive since October it is hard for me to get it straight in my head that I am negative - or am I??!!

Thanks

bjj

Lingering doubts
 

The only other possibility I can think of would be to have the CISH done, a third test used for separating out those who are HER2 from those who are not. And at this point you probably would have to pay for it yourself unless it came back positive and your insurance decided to pay because of all the confusion. But one thing that everyone agrees about is that it is very important to be as accurate as possible because there is a difference in treatment.

AlaskaAngel

P.S. I've only been IHC'd back in 2002 when things weren't very standard anyhow, and you just might have convinced me to go get FISHed or CISHed. So thanks for that push!

this is not unusual
 

Dear bjj,
The IHC and the FISH are entirely different tests. It seems from what we heard at SABCS that FISH+++ is one of the more accurate corollaries to herceptin response. IHC measures the number of HER2 proteins whereas FISH measures the number of HER2 genes. It is possible to have an IHC score of 3+ and a FISH score of 0 on the same tumor sample. The thing about the FISH that makes it so powerful is that it actually measures the genetic copies. It was explaned to us at SABCS that this genetic copying is like taking a photo copy of a photo copy of a photo copy and so on. The copies get progressively worse.
Regards,
Al

Below is something else I found:

HER2 testing

Tests can be done to find out whether a woman has HER2-positive breast cancer. Testing can be done at the same time as initial breast cancer surgery, or samples of cancer tissue from previous biopsies, or surgery, may be used.

The two main methods used for testing are Immunohistochemistry (IHC) and Fluorescence in-situ hybridization (FISH):

Immunohistochemistry (IHC)

Immunohistochemistry (IHC) can show how much of the HER2 protein is present in the tumour sample. The HER2 level is graded from 0 to 3+

• 0–1+ means that a normal amount of the HER2 protein is present and the result is HER2-negative.
• 2+ means that a moderate amount of the HER2 protein is present.
• 3+ means that there is a higher than normal level of HER2 protein and the result is HER2-positive.

When a tumour is scored at 2+, UK testing guidelines recommend that an extra test is carried out. This is because a result of 2+ does not always mean a cancer cell has a high level of HER2. In this situation, an extra test (known as FISH) is used to give a definite result.

Fluorescence in-situ hybridization (FISH)

Whereas IHC measures the level of HER2 protein in the tumour sample, FISH testing measures the amount of the HER2/neu gene in each cell. This gene is responsible for the overproduction of the HER2 protein.

There is no number scale for FISH testing. The result is either:

• FISH negative - normal levels of the gene are present, or
• FISH positive – excessive amounts of the gene are present. This is sometimes called gene amplification.

http://www.cancerbacup.org.uk/Cancer...is/HER2testing