FISH ratio

Hi all,

I've never posted before but I do read the list occassionally. I have a question based only on curiosity (no "need" for this info, treatment-wise).

I know that FISH is more reliable than IHC in determining HER2neu status. FISH is typically reported as simply + or - . But if you look at the actual assay report (at least mine is this way), there is a ratio value given. On mine, the reference says that while there is no "reference range" for the results, a ratio of HER2/Cep17 greater than 2 is considered positive. Still, they give the actual ratio value, and mine is considerably higher than 2. I can't find any information on whether this has any meaning. But of course, my logic, such as it is, says to me that a higher ratio is probably not good news.

Do those of you who are HER2+ have the report of the ratio (HER2/Cep17), or is it simply "+".

Does anyone have references to whether they've investigated the meaning, if any, of a higher vs. lower ratios?

Thanks
Debbie Laxague

The way mine read 2 1/2 years ago was her2-3 or her2+++. From my understanding the higher you are positive the more effective herceptin works. Ladies if I am wrong please correct me! Hope this helps!

Thanks, Carlye,

The results you mention (3+ or +++) were most-likely from an IHC assay. The more-reliable FISH assay usually just reports positive or negative (any ratio under 2 is negative, above is positive). But on the full page report, mine lists a number for that ratio (HER2/Cep17 ratio), and that's what I'm asking about.

Debbie

I thought I was the only one with a ratio for HER/2.Mine is 3.5. The link Lolly gave you is where I got my info. But even after reading that I still just had to assume that the higher the ratio the more positive it is. I'm still trying to find out more.

May I suggest you call your hospital/clinic's pathologist? I'm sure he/she would be happy to explain the test. And when you find out, let us all know!

Love and light,

Lisa

Thanks, Lisa, for the suggestion. The FISH test wasn't done here - it was done an NSABP lab. And my sense is that those performing the test just know how the test works - not the significance of the results, apart from positive and negative, anyway.

Another question that has arisen is that some women have their HER2neu reported as a ratio (HER2/Cep17) and others have it reported as "x" number of copies amplified. We're wondering if that's the same thing or not.

There must have been some work on this, at least early-on in the process of evaluating Herceptin, to decide what level was positive. You'd think that in that process they'd have looked at the significance, if any, of the wide range of values that comprise the "positive" category.

So far, on this board, the bclist, and with my amateur Googling, I've learned a little more about this (the pictures of how they read the slides were beautiful - thanks again) but have not come close to an answer to my question. Maybe it's another question without an answer.I'm getting used to that.

Debbie