A step toward a saliva test for cancer

September 1, 2011

A new saliva test developed by researchers at National Chung Cheng University (NCCU) in Taiwan that can measure the amount of potential carcinogens stuck to a person’s DNA was reported during the 242nd National Meeting & Exposition of the American Chemical Society (ACS) in Denver.

“The test measures the amount of damaged DNA [DNA adducts] in a person’s body,” said Professor Hauh-Jyun Candy Chen, Ph.D., who led the research team,  ”which may help doctors diagnose diseases, monitor how effective a treatment is and also recommend things high-risk patients can do to reduce the chances of actually getting a disease.” The research team also found that saliva samples are more convenient than urine and blood.

DNA adducts forms when a potentially cancer-causing substance is chemically attached to a strand of DNA. People come into contact with such substances in the environment, certain workplaces and through everyday activities such as smoking.  When such a substance binds to DNA, it changes the DNA so that genes may not work normally. Our body has a built-in repair system that can naturally clear up such damage. If that system fails, however, a DNA adduct could lead to mutations or genetic changes that, in turn, could lead to cancer. DNA adducts also accumulate with aging.

The new test measures the levels of five key DNA adducts, including some that form as a result of cigarette smoking. The DNA is present in white blood cells found naturally in saliva and from cells shed from the lining of the mouth. Chen uses a very sensitive laboratory instrument called a mass spectrometer to analyze for DNA adducts.

Chen envisions several uses for any potential commercial version of the test, which she said would probably cost several hundred dollars. One, for example, might be health promotion among people exposed to carcinogens due to lifestyle, occupation or other factors.