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Breast Test Aids Early Detection

Research * Buzz grows about milk-duct exam for women at high risk of developing cancer. But some experts warn that it has a narrow use.


A new test that uses milk-duct cells to assess the risk of breast cancer is showing considerable promise and could help more women better understand how likely they are to develop the disease.

Called ductal lavage, the test is designed to detect changes in cells that are the precursors to breast cancer. The minimally invasive test, which can be performed in a doctor's office, is approved for use in high-risk women.

"There's an understandable buzz and interest around it," says Sally Cooper, director of information services for the National Alliance of Breast Cancer Organizations. "The promise of ductal lavage is so immense. But at this point in time, it's for a very specific use."

Enthusiasm is so high, however, that cancer activists--and even the company that makes the technology--say its importance may be exaggerated.

When it was approved for use last year, 1,500 doctors applied to undergo ductal lavage training--considered a large response for a new technology, according to Susan Bro, a spokeswoman for the manufacturer, ProDuct Health, of Menlo Park. So far, doctors have been trained in about 100 centers across the nation

"There has been tremendous demand and inquiry," Bro says.

Ductal lavage, which was developed by breast health expert Dr. Susan Love and researchers at UCLA, is a 20-minute procedure that collects samples of cells from the milk ducts. About 95% of breast cancers are thought to originate in ductal cells.

After many years of growth, these cells form a tumor that can be detected by mammography or during a physical examination. But by that point, the cancer has usually been present for five to 10 years, according to research.

Ductal lavage was designed to find evidence of abnormal or malignant cells before a tumor develops.

If abnormal cells are discovered, a woman can have a biopsy to further examine the tissue, have the duct surgically removed to eliminate the risk, or take tamoxifen, a powerful drug that has been found to reduce the chances of breast cancer in high-risk women.

"I think this is a first big effort in the modern era to address, biologically, the first steps for breast cancer development," says Dr. William C. Dooley, a University of Oklahoma expert who has conducted a major study on ductal lavage. "If women who had invasive breast cancer in one breast have a positive ductal lavage in the opposite breast, then you could benefit from tamoxifen. These women may not otherwise get tamoxifen."

Before the procedure, anesthetic cream is applied to the nipple area. Suction is used to draw tiny amounts of fluid from the milk ducts to the nipple surface. These fluid droplets identify the milk ducts' natural openings.

A hair-thin catheter is inserted into the duct along with anesthetic. A saline solution is then administered to rinse the duct and collect cells. The cells are analyzed for malignancy or for atypia, which means the cells aren't cancerous but aren't normal.

The test, which costs $400 to $800 and may be covered by insurance, can be done in a doctor's office. The majority of the women who have had the test describe it as uncomfortable but not painful, according to ProDuct Health.

"Ducts are distended 600 times their normal size with cells growing in them before you can feel a tumor," Dooley says. "By then, the tumor has usually broken out of the duct and irritated the surrounding tissues. We're looking for that inflammatory response during mammography. But that is five or seven years into the process. So we are really very late with mammography, even though it's our best tool."

However, ductal lavage is not a replacement for mammography or physical breast exam. The Food and Drug Administration approved the technology only for high-risk women and only in conjunction with mammography.

That point may be lost on some enthusiasts of the test, says Barbara Brenner, executive director of Breast Cancer Action, a San Francisco-based consumer advocacy organization. Only one major study has been done on ductal lavage, Brenner points out.

"All of a sudden, everyone is all over ductal lavage saying, 'Oh, look, we've solved the breast cancer detection problem.' We only wish. I think it's fairly clear that it's not quite ready for prime time."

The one study that has propelled ductal lavage into the limelight is an ongoing examination of 507 women at high risk for breast cancer and who had a mammogram or physical exam within 12 months of the start of the study showing no sign of cancer.

High-risk is defined as women who have a personal or family history of breast cancer as well as other factors, such as carrying the BRCA 1 or 2 genes (which significantly increase the risk of breast cancer) or having had two or more benign breast biopsies.

Eighty-four percent of the subjects yielded nipple fluid--a necessary step to allow completion of the procedure. Of these women, 383 underwent the ductal lavage. The laboratory analysis showed that 23.5% of the women had abnormal cells and 0.5% (two women) had malignant cells.

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