FISH test

Hi:

I am/was a "late" herceptin starter.

My original Her2 test was IHC, done at a local hospital, over two years ago. At that time, the result was 3+ Her 2 and I have always considered myself Her2 +. After my original diagnosis of Stage II, neg. node IDC, I changed hospitals and received my treatment at a large cancer center.

This spring I decided to start adjuvent Herceptin for a year. After reading the posts at this helpful website and looking at my other tumor factors, I realized I am a somewhat unusual Her2 positive patient. Being a medical technologist, I requested a FISH test, just to be "sure."

Surprise! I am FISH NEGATIVE! FISH is the more accurate test. I am NOT a candidate for Herceptin. While waiting for the results of the FISH test, I did receive three Herceptin infusions--but now I will stop.

There are false positives (or human error) with the IHC test. The IHC test is a more subjective test than the FISH test.

Even if you are 3+ IHC, I would suggest getting a FISH test to confirm your diagnosis. Many more patients will be getting Herceptin for adjuvent therapy. I hope they all receive a FISH test.

This website has some interesting discusions about IHC vs FISH:

http://www.herceptin.com/herceptin/p..._about/ihc.htm

Good luck to everyone...you have been a wonderful source of information.

Linda

Just to clarify-- it is possible to be HER2 pos. on the IHC test, but negative on the FSH test and still benefit from Herceptin. The tests are different and measure HER2 in different ways. It isn't as simple as one test being more accurate than the other.

On the IHC test I was 2+. On the FISH test, I was 8.6, which I believe is quite high for HER2+.

Hi:

From what I understand, if you are negative for FISH, you will not benefit from Herceptin.

In my case, I believe the original small hospital lab made a mistake on my IHC test. I don't think I was ever a 3+. There are a lot of varibles in the IHC test that can cause a wrong result.

Although rare to have an incorrect positive IHC, it happened to me and I know of another person who was labeled IHC3+ but negative for FISH.

In my opinion, there is a way to double check the IHC test, which would be FISH. I think the clinical trial subjects all were confirmed Her2+ by FISH. Unfortunately, the FISH test is expensive and time consuming so it is not routinely done.

I almost went through a whole year of Herceptin which would have been of no benefit to me. My result was 1.5 by FISH.

To give myself some peace, I am going to have both tests done again!

Linda

Linda
I am also in a similar situation and am questioning wether I am truly her2 +. My tumor is rather unorthodox for her2 as well. Can you tell me what factors made you decide to retest. I have a very small tumor and they say that I have to choose which tests I want done as there is not enough of it to do all the tests needed. Can you share? I tried to email you but it came back undeliverable. My email is pfowles@charter.net

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

Hi Linda--

I'm glad to hear that you're getting your IHC confirmed. It is possible to be IHC positive, and FSH negative and still benefit from Herceptin... as long as you're strongly positive on the IHC. The link I've included from this site provides more detail re: the different test results and response rates to Herceptin. I've questioned my Onc about this issue as well, and feel comfortable that Herceptin will be a benefit to me (IHC 3+ and FSH -).

The one thing that seems to be clear is that having these tests done by a large testing center is key-- the more a lab does of these tests, the less likely they are to make a mistake.

Good luck!

Jen

Hi, Jen:

Thanks, for giving me the info. I have a meeting in two weeks with my oncologist and you've given me more questions to ask. Things can get very confusing...

Linda

[Rozebud]

It goes both ways too. In this study 3 out of 19 people (15%!!) who tested negative on IHC were actually positive on FSH and could have benefited from herceptin!!

http://www.breastcancer.org/research...in_050002.html

IHC postive, FISH negative. What is your serum HER2?

I am still waiting to find out if I need Herceptin. I am 1 year out of chemo, however, they just tested my pathology with the FISH method and found out I was negative. Now, the onc and I are in limbo while she confers with the pathologist. I feel that I would benefit from Herceptin as there is always the unknown possibly out there lurking in a vessel waiting to create havoc and I would like to destroy it.

[Christine]

Hi Linda

I never had the FISH test, since this assay test was not yet given. This test measures the entire her2 protein therefore showing the pathologist the real count under a microscope. I was determind to be a strongly 3+ and I proved to be so. Herceptin in 1 infusion helped me tremendously. I was stage 4 with a fluid filled lung that all went away in 3 days. I feel it is a very accurate test; and never found it necessary to go for the FISH assay test. However it is a test to have to determine the DNA her2neu status+ or -and is necessary test to have to enter most clinical trials. After my battle with brain metastases, I feel herceptin continues to help me stay NED. ihc WORKED FOR ME, AND I DO UNDERSTAND THAT FALSE + OR - exists so that is why I feel at the time of biopsy both tests should be performed especially if one test alone results in a negative her2 result.
I wondered as I was reading your post if you had taken herceptin for a few rounds before repeating the her2 test. That would definitly give you a false negative. Being + and then - is unusual: it's usually the other way arround( - to +). Those tested - usually test again to find out it can be a different result. being +++ is actually a great reult to have with herceptin beiing your most powerful weapon along with another chemo (there are many compatible chemotherapy's. I would definitely like to know which of the two tests is right? Ask for a retake. Your Onc should understand.
So I felt you should know my story. Warm Hugs, Christine

anyone else IHC+++ and fish -?

Hi:

I was the original poster, who had an IHC 3+ and a FISH negative result. Since then, my oncologist and I have been trying to decide what this means. Dr. Edith Perez, who is one of the top researchers on Herceptin, feels a positive on either test could mean a benefit from Herceptin. She even commented that the IHC test, done correctly, may be a better indicator for Herceptin benefit. Not all doctors agree with her theory.

In the trials, there were a few women who were IHC 3+ and FISH negative. They were considered candidates for Herceptin and included in the trials.

As I understand it, the IHC test is looking for a protein on the outside of the cell. The FISH test is looking more at the genetic material inside the cell. So the tests are measuring two different things.

I also discovered that the local hospital, which did my original IHC test in 2002, changed the way they were doing the test in 2003 because of non-compliance with the FISH test. Insurance is turning me down for a retest so I may pay out of pocket. I think there is a very good chance that the original IHC test result of 3+ is incorrect and I was never Her2 positive. I think the IHC test should be done at a high volume, experienced lab. The FISH test is probably always done at a large reference lab.

When the tests were done, they used the tumor sample from my 2002 lumpectomy. My recent Herceptin treatments wouldn't affect the tests.

Even if I eventually come out 3+, I do not think I will begin the Herceptin again. I am now three years past my AC chemo, had many minor Herceptin side effects, and I am dealing with a cardiac issue (not caused by Herceptin). I'm at the point where the risks outweigh the possible benefits.

It's all so confusing...even for the oncologists. I've been hearing a lot of "we just don't know."

Linda

[Gina]

Linda,

This her-2 stuff is really sneaky...if I were you...just to be on the double safe side...I would also INSIST that my blood levels for CA 27/29 and Serum Her-2 be measured for several months just in case.

Not to scare you, but I have read data (posted somewhere here on this site back in August I think) and witnessed several cases where a girl could have her-2 in the blood and not have it show up on the tumor...it is not always as clear cut as it seems...fyi. According to the article, you can also have it on the tumor and never have it show up in the blood at all...and then, these are the 15 to 20 percent of folks who, by default, can't really use their tumor markers to follow the disease progression and regression..fyi.

Of course, if you are absolutely positive that there is no elevated serum her-2 levels circulating in your blood and your CA 27/29 is 10 or less, then, odds are good that you do not have her-2 at the moment..., but if you stay off the herceptin and within 6 to 8 months start getting sick again...I would revisit the whole issue as odds would be likely you are still her-2 plus...and get back on the Herceptin as fast as possible as her-2 is not something you can be lax about...and I should know...as for years..early on, I tried to be lax about it and it nearly killed me..uh... 7 times...sighhhh. So I am just speaking from my heart on this matter.

That is just my take on it,
Gina