An oral rinse could be used to detect certain types of head and neck carcinoma. Examination of cells from the oral cavity can detect hypermethylated genes in abnormal cells.
Lead researcher Joseph Califano, MD, from Johns Hopkins Kimmel Cancer Center, in Baltimore, Maryland, said a saliva test is a better bet than a blood test in these cases, because some head and neck cancers do not shed genetic material into the blood.
A similar proposal, an oral rinse to detect head and neck cancer, was described last year by Elizabeth Franzmann, MD, from the University of Miami. That test was based on a protein biomarker but Dr. Franzmann and colleagues reported that combining that with a test for hypermethylation increased its accuracy.
In the current study 211 patients with head and neck cancers were compared with 527 healthy individuals. Everyone took the saliva test, which involved using a stiff brush on the inside of the mouth and throat, and then rinsing and gargling with a salt solution. The resultant cell-laden saliva sample was then analyzed.
The researchers identified 8 genes that were the best predictors of head and neck cancer, and then tested saliva with several different panels containing 3 to 5 genes.
The accuracy for prediction of these cancers was between 91% and 97% accurate, depending on which actual genes were tested for. This is a sensational degree of accuracy I approve of. Such a simple and non-invasive test (that doesn’t involve messing with the tumor and therefore spreading dangerous cells) is to be applauded.
The difficulty still dogging this kind of test is that the more sensitive it is made, the more false positives show up. It’s a trade off between sensitivity and specificity. However, it’s a great way forward in checking up on those at high risk or who have already had a head and neck cancer and doctors are looking for possible recurrences.
Clin Cancer Res. 2008; 14:97-107.