A Johns Hopkins breast surgeon has developed an important new way to find breast cancers that would otherwise go undetected by existing techniques. The procedure also improves women's chances for breast-conserving surgery.

The technique uses a novel endoscope that allows surgeons to visualize breast tissue magnified up to 60 times normal size. Physicians are able to pinpoint small lesions currently undetectable by mammography and magnetic resonance imaging (MRI). The procedure has been tested on 55 patients with a 75 percent success rate.

"Endoscopic breast procedures have been tried in the past but were unsuccessful because they are technically difficult to perform and because the scopes used were too large," says William Dooley, M.D., director of the Johns Hopkins Breast Center and the physician who developed the technique.

"The endoscope we developed is less than 1 millimeter in diameter, about the size of the lead in a mechanical pencil," he says. Dooley inserts the endoscope through the nipple into the ducts that line the breast. He then injects saline solution to open the ducts, and through the tiny scope is able to examine the breast tissue, identifying breast lesions up to 1/100 of the size of those seen with mammography and MRI. Researchers caution, however, that this technique is best used in conjunction with standard diagnostic tests. It is useful right now for women with nipple discharge or tumors cells in their breast fluid and whose cancers were undetected by mammography and MRI.

Another benefit of using the endoscope is that it helps limit the extent of surgery for women newly diagnosed with the disease. "Because we can see the tumor so clearly through the endoscope, we can easily find the margins of the tumor and thus are able to conserve more breast tissue. Patients that in the past would have received mastectomies, which involves removing the entire breast and lymph nodes under the arm, are now candidates for lumpectomy," says Dooley.

Clinical trials of the endoscopic technique are now being expanded to include detection of precancerous breast lesions. Women interested in finding out about the study may call 410-955-2615.

More than 180,000 women are diagnosed with breast cancer annually in the United States. When detected early, it is almost always curable. However, when the disease spreads beyond the breast to surrounding lymph nodes and organs, survival rates decline. Approximately 45,000 women die each year from the disease.

October is National Breast Cancer Awareness Month.