The cells lining the mouth reflect the molecular damage caused by cigarettes in the lining of the lungs, U.S. researchers reported.
Examination of oral tissue lining the mouth to measure the molecular changes that cause lung cancer can save patients and people at risk of lung cancer from the uncomfortable procedure that is used currently, said the team of researchers.
They hoped it would be possible to one day wipe the mouth of smokers to predict who will be stricken with lung cancer, thus avoiding the dangerous and painful biopsies in the lung.
That process may also lead to the examination that will predict other cancers, said Dr. Li Mao, an expert in head cancer, neck and lung cancer at MD Anderson Cancer Center, University of Texas, in Houston.
"Our study opens the door to increase our ability to predict who has higher probability for esophageal cancer associated with tobacco," Mao said in a statement. "Not only lung cancer, but pancreatic cancer, bladder and head and neck, which is also related to tobacco use."
Smoking is the major cause of lung cancer, but only as much as 10% of smokers attacked by the disease. The disease causes few symptoms until the developing world, which means patients are rarely diagnosed or treated until it is too late to treat.
Mao's team wanted to find a way to monitor patients who use one drug, COX-2 inhibitor celecoxib, sold by Pfizer (PFE.N) under the name Celebrex, hoping to prevent lung cancer.
They studied two genes known to help prevent cancer development, Q16 and FHIT. There is a fundamental damage (in both genes) long before the cancer struck, "said Mao.
When speaking at the meeting of the American Association for Research Center in San Diego, they said they were seeking special damages in both of these genes in lung samples from 125 smokers and mouth long.
"We're talking about just checking in to obtain the same information we may gain from brushing the lungs obtained through bronchoscopy," said study presenter Dr. Manisha Bhutani who worked with Mao.
The team is reviewing and oral tissue lining the lungs called the epithelium, in 125 chronic smokers enrolled in the study.
The status of two important genes that suppress tumors analyzed. Genes, Q16 and FHIT, are known to damage very early in the process of cancer development.
Study participants were given samples of the mouth and lungs at the beginning and then three months later. Researchers track whether Q16, FHIT or both had been broken. Comparison of their basic network showed the same percentage of damaged genes in the cells of the mouth and lungs.
Q16 gene is closed through a process called methylation in the lungs as much as 23% of volunteers, while FHIT affected at 17%. In the mouth, Q16 damaged in 19% of smokers and FHIT in 15% of them.
In 95% of their genes affected people, they are affected in the mouth and lungs, Mao and Bhutani said.
"Our study provides the first systematic evidence that the network can be penetrated, oral epithelium, can be used to monitor molecular events in tissues that can not be penetrated," said Bhutani. "This gives the bio-monitoring methods appropriate to provide views into the molecular events that occur in the lungs of chronic smokers."
One area continued in the study is to find additional bio-makers at the mouth tissue.