Spit Test Spots Head and Neck Cancer
Researchers Also Working on Oral Swab Test for Lung Cancer
Mouth May Give Clues to Lung Damage
In the second study, researchers found that molecular damage to the cells
lining the mouth can reflect similar damage in the lung tissue. This damage can
eventually lead to cancer.
The current method of getting lung tissue for examination requires a
bronchoscopy, during which a doctor inserts a flexible tube through the
patient's nose or mouth and down to the lungs. It can be downright unpleasant,
says Li Mao, MD, a specialist in head, neck and lung cancer at the University
of Texas M.D. Anderson Cancer Center in Houston.
So the researchers came up with the idea of using oral tissue as a surrogate
marker, he says.
The test is cheap and simple, adds Manisha Bhutani, MD, who also worked on
"Using a swab-sized stick with bristles on the end, we can get the same
information from a brushing inside of the cheek that we would from lung
brushings obtained through bronchoscopy," she says.
Test May Miss Damage
The team examined one sample of oral tissue and six samples of lung tissue
from 125 longtime smokers.
They looked for two genes that protect against the development of cancer --
p16 and FHIT.
"If these genes are silenced, they can't protect against cancer,"
Mao says. "There is substantial damage long before there is
In more than 90% of cases, if the genes were damaged in the mouth tissue,
they were also damaged in the lung tissue.
Mao says there's still a way to go to ensure the oral test doesn't miss any
The ultimate goal of the research is to identify individuals at high risk of
lung cancer before they have signs or symptoms of the disease, Mao says.
Although the test is being developed for smokers, he says that it could be
used to weed out other people at high risk of lung cancer.
Otis W. Brawley, MD, chief medical officer at ACS in Atlanta, says that
"the approach makes a great deal of sense. But it will be a long time
before we can get this to the patient."