Researchers at the University of California at San Francisco used something similar to a breast milk pump to draw fluid from the milk ducts in the breast for analysis. A small cup is placed over the nipple and the cup is attached to a tube. The tube is attached to a syringe, that when pulled back, creates a vacuum that draws fluid out of the breast ducts and out through the nipple.
Employing this technique, called nipple aspiration, they collected breast fluid samples from 3,271 non-lactating women from 1981 to 1991. They then followed the women's health until 1999 to see who developed breast cancer.
Women who produced fluid containing abnormal cells were twice as likely to develop breast cancer as women from whom no fluid could be withdrawn and were 60 percent more likely to develop the disease as compared to women whose fluid samples carried only normal cells, researchers report. Their findings are published in Wednesday's issue of Journal of the National Cancer Institute.
These results are consistent with previous research UCSF conducted in the 1970s and 1980s, in which breast fluid samples taken from 1972 through 1980 were analyzed to determine who went on to develop breast cancer. That research also showed women who had abnormal cells in their fluid samples had greater chances of breast cancer down the road.
"It's a method for getting information about what's going on in the breast ducts, which is where many of the breast cancers start," lead researcher Margaret Wrensch, told United Press International. Abnormal cells could be a red flag to doctors, Wrensch explained, by highlighting who is at greatest risk of getting breast cancer. Having this additional information from fluid samples, "could short circuit the disease process," Wrensch said.
Scientists have been searching for a way to better predict who could develop breast cancer because earlier detection of the disease means greater survival odds. Mammography, in which X-rays are taken of the breast tissue and is usually only offered to women in their 40s and older, is still considered the gold standard for breast cancer screening.
"This should not replace mammograms as a screening tool," Dr. Helen Pass, director of the Breast Cancer Center at William Beaumont Hospital in Royal Oak, Mich., told UPI. "It should be viewed as an additional tool as part of the repertoire for high-risk women."
Pass said 80 percent of all breast cancers start in the milk ducts and it would make sense to analyze fluid from there, but this method might not be advantageous for large-scale screening for all women. Abnormal or dying cells being naturally passed out through the ducts could be mistaken for something more serious, especially if those cells turned up in a woman with no breast lump or family history of the disease, Pass explained. Breast fluid analysis, she said, "is not for every woman."
But Wrensch said it's possible health care visits of the future could include breast fluid analysis, particularly for younger women, like the Pap smear is used to detect cervical cancer during a routine gynecological exam. "We think, in fact, it would be most useful in women who are under the (age of) mammography screening."
(Reported by Katrina Woznicki in Washington)