Oral bacteria could point toward cancer diagnosis: study
Scientists from the Forsyth Institute have identified three species of oral bacteria whose elevated levels can be positively associated with increased incidence of oral squamous cell carcinoma, a discovery that could facilitate development of a saliva-based diagnostic test for this deadly form of cancer.
"Finding bacteria associated with oral squamous cell carcinoma encourages us to hope that we have discovered an early diagnostic marker for the disease," said Dr. Donna Mager, assistant member of the staff in Forsyth's Department of Periodontology and Molecular Genetics. "If future studies bear this out, it may be possible to save lives by conducting large-scale screenings using saliva samples."
Nearly 30,000 Americans will be diagnosed with oral or pharyngeal cancer this year, according to the American Cancer Society. Ninety percent of oral cancer lesions are oral squamous cell carcinomas (OSCC), the Forsyth team noted, with a five-year survival rate of 54 percent despite advances in surgery, radiation and chemotherapy.
For their study, the Forsyth investigators collected saliva samples from 229 cancer-free subjects and 45 subjects with OSCC and evaluated the samples for their content of 40 common oral bacteria. Of the 40 types of bacteria tested, three species in particular were elevated in the saliva samples from the subjects with OSCC. The investigators obtained similar findings when they controlled for gender, age and smoking history.
"Those results led us to hypothesize that the three species could serve as diagnostic indicators for OSCC," Dr. Mager said. "And, in fact, we found that elevated salivary counts of the three bacteria correctly identified 80 percent of individuals with oral cancer and 83 percent of controls."
If the findings of the study can be replicated, the Forsyth team envisions development of a simple saliva test to diagnose OSCC administered in large screenings and analyzed by a diagnostic center with results returned within days.
But in the meantime, Dr. Mager noted she "cannot overemphasize" the importance of patients getting examined for signs of oral cancer at least once a year.
Please contact the ADA if you have questions about this article.
©2010 American Dental Association. All rights reserved. Reproduction or republication is strictly prohibited without the prior written permission from the American Dental Association.