The discussion revolves around different arms of the herceptin adjuvant trials. Early on, there were multiple studies using herceptin in conjunction with different adjuvant chemo regimens.
Eventually, the two studies were combined into one large study. Both the AC->TH and TCH arms showed significant improvement in survivability over the non-herceptin arms.
There are advantages/disadvantages to both AC->TH and TCH regimens.
AC->TH can, in some patients, harm cardiac muscle. If a patient has a previous cardiac history, then this regimen may be considered risky. However, the interim results of the study showed a slightly greater success rate with this treatment. It was not known if long term follow-up would show a statistically significant difference between this and TCH.
TCH has lower cardiac toxicity rates, but may be less effective against tumors that co-amplify TOPO2. There are no easy tests for the co-amplification. I think only one or two labs are available to do this test and most insurance will not cover.
Essentially, it is a trade-off with "most" oncologists preferring the AC->TH regimen unless there is a reason to go with the TCH regimen. Of course, this may change next week or next month as new information becomes available.
For a discussion of the combined study see the info on BCIRG 006 at the following website.
www.bcirg.org