Saliva test could help catch breast cancer
Screening envisioned for developing world where mammograms are rare

By Will Dunham
Reuters
updated 10:58 a.m. PT, Thurs., Jan. 10, 2008

WASHINGTON - Scientists in the United States are developing a
screening test for breast cancer that checks a woman's saliva for
evidence of the disease to help find tumors early, when they are most
treatable.

In research published on Thursday, the scientists said they identified
49 proteins in saliva that the screening test would track to
distinguish healthy women from those with benign breast tumors and
those with malignant breast tumors.

Breast cancer triggers a change in the type and amount of proteins in
secretions from the salivary glands, said Charles Streckfus, a
professor of diagnostic sciences at the University of Texas Dental
Branch at Houston.

The proteins are produced by tumor cells and affect cell growth, cell
metabolism and cell self-destruction -- all of which go awry in cancer,
Streckfus said.

Streckfus and colleagues tested saliva from 30 women -- 10 healthy
women, 10 with malignant breast cancer and 10 with benign breast
tumors.

The pattern of proteins is different in each of the three groups, the
researchers reported in the journal Cancer Investigation.

More work needs to be done before a screening test based on these
proteins can be made available to the public, Streckfus said. But U.S.
government approval for the test may be sought within five years, he
added.

Focus on developing countries
Mammography and breast self-examination for tumors are leading methods
used for early detection of breast cancer.

But Streckfus said mammograms -- X-rays of the breasts -- are too
expensive in many developing countries and a cheap, easy-to-perform
screening test would be valuable.

"On a global perspective, mammography is not very common," Streckfus
said in a telephone interview. "Even in our neighbor Mexico, there are
very few mammography centers around."

Streckfus said he envisioned a saliva test as a quick, inexpensive and
simple screening method. In developed countries like the United
States, such a test could complement existing screening methods, he
added.

Breast cancer is the leading cause of cancer death among women
worldwide, according to the American Cancer Society.

The organization estimated that about 465,000 women died from it
globally in 2007, with 1.3 million new cases diagnosed. Declining
death rates from breast cancer in developed countries have been
attributed to early detection through mammography screening and to
improved treatment, the organization said.

The American Cancer Society recommends women age 40 and older get a
mammogram every year. Streckfus said the new test could be done more
frequently to find tumors that might arise between mammograms.

Other researchers last week said they were developing a saliva test to
screen for head and neck cancers. Their test also was years away from
being available to the public.

URL: http://www.msnbc.msn.com/id/22594117/