Screening for some cancers may one day be as easy as gargling.
Scientists at Johns Hopkins Kimmel Cancer Center say a new mouth-rinse cancer test holds promise for screening people at high risk for head and neck cancers, including heavy tobacco and alcohol users.
Lead investigator, Dr. Joseph Califano, said his research group at Johns Hopkins asked 211 head and neck cancer patients and 527 individuals without cancers of the mouth, larynx or pharynx to brush the inside of their mouths, then rinse and gargle with a salt solution.
The researchers collected the rinsed saliva and filtered out cells thought to contain one or more of 21 bits of chemically altered genes common only to head and neck cancers. Tumor and blood samples also were collected.
One panel correctly identified 66 out of 154 patients (42.9 percent) with the disease and accurately ruled out the disease in 203 of 248 healthy subjects (81.9 percent), according to the study published in the Jan. 1 issue of Clinical Cancer Research.
Although the blood test was more accurate than the saliva test at detecting cancer in patients with the disease (34 out of 37), there was a trade-off in the number of healthy individuals it spotted (53 of 173), the authors say.
"Few tests can be perfect 100 percent of the time in identifying both normal and cancerous cells," Califano said in a news release. "Because head and neck cancers are not widespread, it makes more sense to screen those at high risk and to focus on a test’s ability to accurately rule out healthy people."
A saliva test also is easy to do, painless and cheap, capturing cells from a wide area of the mouth, Califano said. Some head and neck tumors do not shed genetic material into the blood, making the saliva test a better bet, he said.
Researchers said more studies are needed to refine the test and automate it before multi-institutional clinical trials can begin. One of the first clinical uses for such a test could be to detect recurrence in current head and neck cancer patients, according to the study's authors.