By Will Boggs, MD

NEW YORK (Reuters Health) Mar 15 - Scientific presentations can influence treatment patterns before the research findings are subjected to peer review, according to a report in the March 15th issue of the Journal of the National Cancer Institute.

"I would hope for community physicians to understand the potential risk of early adoption of preliminary data," lead author Dr. Sharon H. Giordano from University of Texas M.D. Anderson Cancer Center, Houston, told Reuters Health. "As physicians, we all want to offer our patients the best therapy. However, it is equally important not to expose patients to unnecessary risks."

Dr. Giordano and colleagues investigated 3341 women with breast cancer who were diagnosed soon after a scientific presentation and widespread media coverage of the results from a trial of paclitaxel for early breast cancer, but before FDA approval for that indication.

The rate of taxane use increased from 5.2% before the May 1998 presentation at the annual meeting of the American Society of Clinical Oncology, to 23.6% after May 1998, the results indicate. The dramatic increase in taxane use was confined mostly to women with lymph node-positive breast cancer, the researchers note.

Multivariable models confirmed that women who started chemotherapy in May 1998 were nearly seven times more likely to receive a taxane than women who started chemotherapy before May 1998.

"This increase was seen well before the data were published in a peer-reviewed journal and even before FDA granted approval for the use of paclitaxel for early-stage breast cancer," the investigators write.

"Moving fast is a gamble," write Dr. Steven Woloshin and Dr. Lisa M. Schwartz from VA Outcomes Group, White River Junction, Vermont in a related editorial. "When preliminary findings turn out to be true, patients benefit. When the findings are not true, patients get hurt: They are exposed to ineffective or harmful treatments, or they forgo good alternatives."

"Physicians are confronted with preliminary research findings all the time," the editorialists conclude. "To decide whether the findings are good enough to change practice, they must be able to answer some fundamental questions. The most basic question, of course, is what is the rush?"

"Presenters at scientific meetings need to be aware of the potential impact of their presentations and take great care to provide balanced presentations on a topic," Dr. Giordano said. "Additionally, timely publication of findings that can stimulate practice change is very important."