JOYCE O'SHAUGHNESSY, MD: They are both used for women where the primary breast cancer has been removed, and they have just been incorporated into different regimens. One is called CAF, and the other one is called CEF. You can see that the only difference there is whether you're using the adriamycin or the epirubicin, adriamycin, or Ellence -- the other name for epirubicin. But they are both used -- you don't use them together. You use them as part of combination chemotherapy, because we do know, also, from clinical trials that combinations of chemotherapy cure more women than just using one agent by itself.
TERRY P. MAMOUNAS, MD: Although those two anthracyclines are very similar in structure, minor differences in structure result in certain differences in the pharmacology in terms of uptake of the drug and metabolism of the drug. As a result of that, there are some differences in clinical endpoints. Certainly, there are differences in toxicity, particularly cardiotoxicity. So if you compare the two anthracyclines milligram per milligram, epirubicin is less cardiotoxic than doxorubicin.
As a result, epirubicin has been able to be intensified in higher doses of anthracycline, and several studies have shown that by increasing the dose of epirubicin, one can get actually an increase in benefit as compared to the other anthracyclines, adriamycin or doxorubicin, which actually we haven't been able to show and differences by intensifying its dose.
KATHLEEN PRITCHARD, MD: I think the biggest window of difference is for the cardiac effects, where you can give almost twice as much, milligram per milligram, epirubicin as you can adriamycin before seeing the same kind of cardiac problems.
