It seems that the cancer-industrial complex has some statistics about how well patients will respond to specific treatments, based on results from both IHC and the FISH test. IHC grades HER2 from 1 to 3 (where 3 is positive), and FISH uses something called the HER2/CEP17 ratio, where anything greater than 1 can be positive. There is at least one study that shows that if you have a HER2/CEP17 ratio greater than 3, you are more likely to get a longer-term remission on a first-line of anti-HER2 treatment (TH in this study, as there was no P yet), and if your HER2/CEP17 is less than 3, you are likely to have a weaker response to Herceptin.
So why are HER2 patients not made aware of this calculation? For example, it seems that, if you have a HER2/CEP17 higher than 3, you might want to continue with Herceptin paired with other therapies after your first-line treatment, and, conversely, you might want to look beyond anti-HER2 therapies if your HER2/CEP17 is less than 3.
Article is here:
http://www.ncbi.nlm.nih.gov/pubmed/23673443
I am sure there are other, similar studies that could help patients in their treatment decisions. The best solution would be to have everyone's tumor sequenced. I spoke to the folks at the Metastatic Breast Cancer Project at the Living Beyond Breast Cancer conference in Philly, and when I asked whether those of us who had submitted our tumor samples for sequencing might be able to get the results of those samples, the response was: It is more likely that the insurance companies will agree to pay for tumor sequencing before we would be able to break the confidentiality of our study. The MBC project folks are quite optimistic that insurance companies will begin to pay for this soon.