Scientists use oral tissue to detect damage to the lungs caused by smoking
Researchers at the University of Texas MD Anderson Cancer Center have suggested that the cells lining the mouth can be used as an indicator of the damage caused to the lining of the lungs by smoking.
According to senior researcher Dr Li Mao, professor in MD Anderson's Department of Thoracic, Head and Neck Medical Oncology, the significance of this development is that patients could be saved from having to undergo more invasive and uncomfortable investigative procedures as the same results could be achieved through the examination of oral tissue lining the mouth.
"We are talking about just a brushing inside of the cheek to get the same information we would from lung brushings obtained through bronchoscopy," confirmed study presenter and first author Dr Manisha Bhutani, a post-doctoral fellow in Thoracic/Head and Neck Medical Oncology.
The team reached is conclusions following the examination of the epithelium - oral and lung lining tissue - in 125 chronic smokers. Two tumour-suppressing genes - p16 and FHIT - were analysed in detail, as they are known to be affected in the early stages of cancer development.
This involved checking to see whether either p16, FHIT - or both - had been silenced by methylation - a process that turns off genes by attaching chemical groups called methyl groups to the outside of the DNA double helix. A strong correlation between the methylation pattern in both oral and lung tissues was found, allowing Dr Bhutani to conclude that "our study provides the first systematic evidence that accessible tissue, the oral epithelium, can be used to monitor molecular events in less accessible tissue".
"This provides a convenient biomonitoring method to provide insight into the molecular events that take place in the lungs of chronic smokers," Dr Bhutani added.
The results of the study were reported at the annual meeting of the American Association for Cancer Research.
"Our study opens the door to enhancing our ability to predict who has higher probability of getting tobacco-related cancers," Dr Mao said. "Not only lung cancer, but pancreatic, bladder and head-and-neck cancers, which also are associated with tobacco use."