A widely publicized study shows that paclitaxel(Drug information on paclitaxel) administered after adjuvant chemotherapy with doxorubicin(Drug information on doxorubicin) plus cyclophosphamide(Drug information on cyclophosphamide) (AC-T) provides no or only slight benefit to women with HER2-negative, ER-positive, node-positive breast cancer. This has raised the question of what, if any, immediate impact the findings will have on the practice of clinical oncology.

This subpopulation of node-positive patients represents a significant portion of women who currently receive AC-T, and the study authors noted the increased risk of adverse events associated with adding paclitaxel to AC chemotherapy. However, they cautioned that the results "require validation before adoption into clinical practice" (Hayes et al: N Engl J Med 357:1496-1506, 2007).

The advice seemed sound to Andrew D. Seidman, MD. "This is a retrospective, subset analysis," said Dr. Seidman, attending physician for breast cancer medicine at Memorial Sloan-Kettering Cancer Center and professor of medicine at the Weill Medical College of Cornell University. "I think these data simply state that there are subsets of patients who derive more or less benefit from the drug. For myself, I am not ready to abandon the use of taxanes because of these data."

'The ball is already rolling'

Franco M. Muggia, MD, professor of oncology and director of medical oncology at New York University Medical Center, envisions the paper as another step in identifying markers that will enable more tailored treatment.

"The ball is already rolling," he told ONI. "We are getting more and more molecular markers. In general, we are going to be much more selective in how we use chemotherapies in breast cancer."

Will this new study have an immediate impact on medical oncology? "Yes, I think it will," he said. "The paper comes from a very good source. It is just one of several papers that will undoubtedly change the current treatment."

Added Dr. Seidman: "These data allow us to apply some art to the science of medicine. For example, in a patient with a relatively small tumor whose lymph nodes are negative, where we know there is going to be a benefit of both chemotherapy and perhaps the use of an antiestrogen, these data suggest there would be little if any incremental advantage to adding paclitaxel."