I am HER2++, will Herceptin be of any use to me

as I m only +2, I was wondering if Herceptin would work for me, my onc. told me that it is usually used for +3 so I'm not sure if I'll have it, can anyone advise?

Thanks, love Ally xx

Hi Ally,

My wife was found to be +2-+3 based on IHC testing which, as I understand , can have a high degree of human error. As a result, I asked that they retest using the FISH method. It's more expensive and time consuming but seems to be more accurate and seems to be a more accurate model for those that might benefit from herceptin. There are others at this wonderful sight that will probably be able to provide you with more specific and accurate info, but I hope that helps. I'm also wondering, will you be receiving the herceptin alone or in conjunction with another drug?
Best, Eric

Hi Eric

I don't really know at the moment. I live in the U.K. and I don't think they've even heard of FISH testing over here, my BC nurse certainly hadn't, and she has been in the business for many years, nor had my insurance company. I will ask my onc. about it next time I see him because I want to be sure of my status.

Ally x

Dear Ally,

Eric's advice is sound. The U.S. research literature suggests that approximately 12% of borderline +2/+3 IHC test results are actually FISH positive -- which means that herceptin could be effective for that 12% population. The response rate to herceptin for that borderline 12% population is about 26%. The response rate for a truly +2 IHC would necessarily be less than 26%; however, at +2 you are still eligible to take herceptin.

As Eric suggested, you really should pursue a "FISH" technology test to determine your definitive HER-2 status. A widely-used U.S. test is the Vysis Pathvysion HER-2 DNA probe kit. The kit is distributed by Abbott Diagnostics (part of Abbott Laboratories, a U.S.-based multinational company). I believe that Abbott has locations in Poland and Germany. I would assume that most major oncology research facilities in Europe have this technology available.

The cross-link below (if you click on it) should take you to the Pathvysion section of the Abbott website. Once at the website, you can access the specific Pathvysion website if you wish. You may want to contact the consumer/technical help line for further assistance and testing locations that you could utilize.

The importance of this issue lies in the fact that the U.S. medical literature is replete with +2 IHC HER-2 test results that, upon retesting by FISH technology, turn out to be HER-2 negative cases (meaning that Herceptin would not effective). As you know, HER-2 positive breast cancer represents an overabundance of the HER-2 gene with a cell. IHC tests for the "overexpression" of certain proteins created by the HER-2 gene. For testing purposes, these proteins are subject to instability. In contrast, FISH testing identifies the "amplification" (or multiple copies) of the HER-2 gene. The DNA within the HER-2 gene is incredibly stable and stands up to consistant and reliable testing much better than the IHC test.

I'm sure if you contact the Pathvysion (Abbott Lab) folks, they should be able to assist your nurse or doctor. Your true HER-2 status (i.e., +2, +2/+3, or +3 by IHC testing, or alternatively FISH negative versus FISH positive by FISH testing) is critical to the results that you can expect from Herceptin.

Please let us know if you require further assistance.

Regards,

Paul

Dear Paul

Thank you so much for such a detailed post. I will check out the website now.

Regards

Ally