Blood Test Could Screen For Breast Cancer

BOSTON -- While mammograms and clinical exams are the best ways to screen for breast cancer, scientists continue the search for more accurate detection tools.

Now researchers say there may be a new screening test on the horizon.

Monica Jones remembers how nerve wracking it was when something showed up on one of her mammograms.

"So I went back in there and had about three more taken, so that was quite an anxiety level," Jones said.

Now, there's a blood test that may one day help reduce that kind of anxiety. It was developed by Matritech, of Newton, Mass., and is being tested at seven sites in the country.

"What our scientists have discovered is a way to identify proteins in the blood of women that have breast cancer that are absent in the blood of normal women," Matritech spokesman Stephen D. Chubb said.

In a preliminary study of blood samples from 78 women, the protein was found in 100 percent of the women with invasive cancer, 80 percent with noninvasive tumors, and no one with a normal mammogram. The downside is that it was also found in 8 percent of those with benign breast conditions.

Dr. Rosemary Duda said that a blood test would be a valuable additional screening tool. For one, it could reduce the number of biopsies that are now performed.

"The mammogram may show an indeterminate lesion and one more test may help sway whether or not the person should have the biopsy or if they could be observed for a period of time," Duda said.

When mammograms are hard to read, as is the case for many younger women who have denser breasts, a blood test could signal that a tumor might be forming. While not a substitute for clinical exams or mammograms, a blood test would offer earlier detection, and for those at high risk, more peace of mind.

"It may be one more level of reassurance that she does not have breast cancer," Duda said.

The test may be available by the end of the year. But experts caution that, while it is an important new tool, it would not be a substitute for mammograms or clinical exams.