They said the term carcinoma creates a lot of worry in women who fear they will develop cancer, even though long-term survival rates for DCIS are excellent, approaching 100 percent. "We've had long discussions about this," Dr. Susan Reed of the University of Washington School of Medicine told a briefing.

She was one of several independent panelists asked by the National Institutes of Health to look into whether too many women are being treated too aggressively for a condition that is poorly understood.

"If you use a word that evokes fear, as the word carcinoma may, I think we need to consider is that appropriate," said Reed, who favors changing the name to something less scary.

DCIS is a condition in which abnormal cells accumulate in the breast duct, but have not spread to other tissues in the breast.

Since the start of widespread mammography screening in the 1980s, rates of DCIS diagnoses have increased sevenfold. By 2020, an estimated 1 million U.S. women will be living with a DCIS diagnosis.

And because most women diagnosed with DCIS get treated for it -- with surgery to remove the cells and sometimes radiation -- little is known about how much of a risk it presents, or whether some women might do well with less or no treatment.

"Despite having had a century of knowledge of the disease, we do not understand the natural history of DCIS, and probably never will," Dr. Carmen Allegra of the University of Florida, who chaired the panel, told the briefing.

After two days of scientific presentations and many discussions, the panel is urging scientists to come up with better ways to determine which women with DCIS might develop invasive breast cancer.

"Given that this diagnosis has significant emotional impact for the women diagnosed with it, we felt it was critical to develop methods that would allow a very precise determination of exactly which patients would ultimately be at risk for developing invasive disease," Allegra said.