[dlaxague]

There's a lot of information on this site ( try: http://www.her2support.org/her2.html ) and others (breastcancer.org is also a good place) about what it means to be HER2 positive. You'll get a better explanation reading that information than from our replies.

Or did you mean the specifics of three pluses rather than two pluses? The test that gives the result in pluses is the IHC test for HER2. A "FISH" test is considered more accurate and it gives the result as one number (although technically it's a ratio). Some labs and/or oncs will not retest a 3+ IHC using FISH. You can ask your onc to double check with FISH but most IHC 3+ are truly positive.

It does not seem that the degree of HER2 positivity has any relation to response to Herceptin. There was a small study posted here recently that said that they did see a relationship but there have been many larger studies that did not, and the experts say that they have no accurate way (yet) to predict who will be in the roughly 50% of those who respond to Herceptin.

I've wondered if the degree of HER2 positivity has any relation to prognosis (in the absence of Herceptin). Anyone know?

Debbie Laxague