A relatively new technique called ductal lavage may help patients at high risk of breast cancer choose strategies for reducing their risk, according to a report in the Nov. 7 Journal of the National Cancer Institute (Vol. 93, No. 21: 1624-1632).

“Ductal lavage can provide a woman with some information about whether she has evidence of cellular changes associated with increased breast cancer risk at the time she is weighing the risks and benefits of tamoxifen therapy,” the researchers write in their report.

Women at high risk of breast cancer may choose simply to be under close supervision of a breast specialist.

Or they may choose to take the drug tamoxifen, which can cut breast cancer risk by about half, but can also cause side effects.

Some may choose to seek enrollment in clinical trials or other approaches to reducing risk.

And some women at extremely high risk of breast cancer may choose to have one or both breasts surgically removed to prevent breast cancer from occurring — called prophylactic mastectomy.

The researchers believe more information about a woman’s individual risk could help high-risk women make these tough choices.

More than 95% of all breast cancers begin in stages within ductal epithelial cells — the cells lining the inside of the ducts — that bring breast milk to the nipple.

If exam of those cells shows potentially pre-cancerous changes called atypia, a woman is much more likely to develop breast cancer in the next few years.

An earlier method of obtaining cells for exam — by suctioning nipple fluid (NAF) from the breast — often provided so few cells doctors couldn’t be sure they hadn’t missed atypical cells when they were present.

In the ductal lavage technique, doctors place an extremely thin tube through a natural opening in the nipple a short distance into a milk duct and rinse the duct with salt water, collecting any cells that wash loose for microscopic exam at a later time.

The researchers, led by William C. Dooley, MD, of the University of Oklahoma, wanted to learn if ductal lavage could more often provide enough cells to judge whether atypia had occurred than could the NAF method.

They used the NAF technique, then ductal lavage, with 507 women at high risk of breast cancer.

Ductal lavage provided enough cells to examine in 78% of the women, compared to only 27% of those with whom the NAF technique was used, providing on average over 100 times more cells. The ductal lavage method also was more than three times as good at detecting abnormal cells.

An American Cancer Society (ACS) breast cancer expert says the technique is not a diagnostic test, nor is it a substitute for mammography, which is still the best screening tool for most women.

“But it could prove to be useful for those at high risk, because there aren’t a lot of tools for more precisely identifying individual high-risk women’s chances of developing breast cancer,” says Debbie Saslow, PhD, director of breast and cervical programs for the ACS.

A breast cancer specialist and surgeon agrees with Saslow that the technique in theory may have the potential to help judge risk, but says that its ability to do so isn’t yet proven.

“It’s difficult to make a judgement about what’s going on in the breast just from cells shed by the breast,” says Jeanne Petrek, MD, attending surgeon at Memorial Sloan Kettering Cancer Center.

Petrek, a member of the ACS breast cancer council, says examining shed cells hasn’t worked out in the past as a way to judge risk of developing other cancers. Only studies now underway can determine if examining cells obtained by ductal lavage will work out better, she says.

“Until then, it’s a huge leap of faith to say this technique is ready for prime time,” notes Petrek, who also expresses concern that some doctors offering it are promoting it before its value has been fully proven.

Saslow says an article soon to be published in the medical journal Cancer will suggest guidelines for ways doctors can best use exam findings from ductal lavage or the NAF technique. A doctor can learn how likely it is a woman at high risk will develop breast cancer in the next few years, and ways to use that information to help choose methods to deal with that level of risk.

“While additional studies are underway, it’s something that women at high risk of breast cancer may want to discuss with their doctors,” says Saslow.