HER2 Support Group Forums - View Single Post

al from Canada · 12-19-2005, 01:00 PM

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

12-19-2005, 01:00 PM	#3
al from Canada Senior Member Join Date: Jul 2005 Location: Ontario, Canada Posts: 722	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 __________________ Primary care-giver to and advocate for Linda, who passed away April 27, 2006.