Saliva-based tests detect oral cancer

Early diagnosis of oral cancer and Sjogren's syndrome, an autoimmune disease involving dry eyes, dry mouth and rheumatoid arthritis, may soon be possible with saliva-based tests. If oral cancer can be caught at stage 2 instead of stage 4, a patients 5-year survival rate can be improved by 50 percent, which would be of tremendous service not only to the quality of life of the individual, but also to the healthcare burden of the country. Researchers from the University of California in Los Angeles, USA, examined 350 saliva samples from patients with oral cancer and healthy comparison subjects. Seven messenger RNAs, which are used to build proteins, were increased in the patients with oral cancer. Based on their findings, the researchers developed a test that is fairly accurate in detecting oral cancer. The researchers noted that the test would be particularly useful for screening individuals with risk factors for oral cancer, including patients older than 45 years, smokers and alcohol drinkers. Meanwhile, researchers from the National Institute for Dental and Craniofacial Research in Bethesda, Maryland, have shown that saliva from patients with Sjogren's syndrome can be differentiated from that of healthy control subjects by varying concentrations of proteins. This should allow to diagnose patients more easily, to observe what actually happens to the salivary gland of patients with Sjogren's syndrome, to develop therapies to halt disease progression, to follow their progress during clinical trials, and to develop more effective saliva substitutes. A diagnosis of Sjogren's syndrome currently requires a biopsy of the salivary gland, which sometimes has to be repeated. It has been long hoped to develop a non-invasive test that can be used instead of biopsy. The researchers used various tests to measure the protein profiles in saliva from 20 healthy comparison subjects and 41 patients with primary Sjogren's syndrome. Their results showed that the concentration of eight inflammatory proteins were increased 2-fold or higher in patients' saliva, while two other proteins were decreased. Replenishing these proteins in artificial saliva will make it more effective in treating patients' symptoms of dry mouth. However, further research is needed before this can be used routinely.