Precancerous Breast Lesions Cause Unnecessary Worry

The choice of treatment depends upon the characteristics of the patient and the lesion, added Partridge, who is also an assistant professor of medicine at Harvard Medical School. The dilemma posed by the prospect of under- or over-treating DCIS is complicated by medicine's current inability to distinguish between "good actors and bad actors" -- lesions that don't recur or go on to become invasive breast cancer and those that do, she added.

Another expert agreed with that assessment.

Everyone would be more comfortable if there wasn't such a "big gray zone" between what is normal tissue and what is invasive cancer, said Dr. H. Gilbert Welch, a professor of medicine at Dartmouth Medical School and an expert on how well health care works for patients. Welch argued that as mammography continues to detect smaller and smaller DCIS lesions, there can be a tendency to over-treat. He recommends that the diagnostic threshold for DCIS be raised to doing biopsies on only lesions that measure 1 centimeter or greater in diameter.

"There is this ironic finding that women with this early precursor lesion may be treated more aggressively than women with invasive breast cancer," he said. "They may have mastectomies instead of just a lumpectomy. At some level we have to say, 'Does this really make sense?'"

Another study in the same issue ofJNCIsuggests that medical science is winning the war on breast cancer. The research, which involved nearly 5,000 breast cancer patients, was led by the National Cancer Institute of Canada's Clinical Trials Group. A total of 256 of the participants died during the four-year study.

The researchers found that older women who had survived for at least five years after a diagnosis of early stage breast cancer were most likely to die of causes unrelated to their breast malignancy. In fact, 60 percent of these deaths were not caused by breast cancer, the Canadian team found.

More information

For more on DCIS, head to the U.S. National Cancer Institute.

SOURCES: Ann Partridge M.D., MPH, oncologist, Dana-Farber Cancer Institute, Brigham & Women's Hospital, and assistant professor, medicine, Harvard Medical School, all in Boston; Michael Stefanek, Ph.D., vice president, behavioral research, American Cancer Society, Atlanta; H. Gilbert Welch, M.D., MPH, Veterans Affairs Outcomes Group, Department of Veterans Affairs Medical Center, White River Junction, Vt., and professor, medicine, Dartmouth Medical School; Feb. 12, 2008,Journal of the National Cancer Institute, online