Mouth-Swabbing Test Could Predict Lung Cancer
U.S. researchers say damage to cells lining the mouth can predict similar damage in the lungs that eventually leads to lung cancer in smokers.
They hope it may one day be possible to predict cancer in smokers by swabbing their mouths so that painful and dangerous biopsies of the lung won’t be necessary.
“The process may also lead to tests that will predict other cancers,” said Dr. Li Mao, an expert in head, neck and lung cancer at the University of Texas M.D. Anderson Cancer Center in Houston.
Mao said the study opens the door to enhancing our ability to predict who has higher probability of getting tobacco-related cancers. "Not only lung cancer, but pancreatic, bladder and head and neck cancers, which also are associated with tobacco use."
Mao’s team hopes to prevent lung cancer by monitoring patients taking the COX-2 inhibitor celecoxib, sold by Pfizer under the brand name Celebrex.
The research focused on two genes known to help prevent the development of cancer””p 16 and FHIT. "There is substantial damage (to the two genes) long before there is cancer," Mao said.
They looked for specific damage to these genes in both lung samples and mouth samples from 125 long-time smokers.
The p16 gene was shut down via a process called methylation in the lungs of 23 percent of the volunteers, while FHIT was affected in 17 percent. In the mouth, p16 was silenced in 19 percent of the smokers and FHIT in 15 percent of them.
Mao said in 95 percent of those whose genes were affected were affected in both the mouth and the lung.
The team presented their findings at a meeting of the American Association for Cancer Research in San Diego.
"We are talking about just a brushing inside of the cheek to get the same information we would from lung brushings obtained through bronchoscopy," said Dr. Manisha Bhutani, who works with Mao.
This would make an easier test for pre-lung cancer than having to access the lung and it could be useful in monitoring and looking to see if prevention measures might work, the researchers said.
"This could have strong implications for further lung cancer prevention trials," the summary said.
At least one other group is working on a saliva test for breast cancer. The test looks for a mutated version of the HER-2 protein linked to some breast cancers.
Smoking is the leading cause of lung cancer, but only about 10 percent of smokers ever get it. There are few symptoms until the cancer is advanced””meaning patients are rarely diagnosed or treated until it is too late for a cure.
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