Researchers at the Johns Hopkins Kimmel Cancer Centre have said that morning gargle can help spot head and neck cancer.
The study, led by Joseph Califano, an associate professor of otolaryngology - head and neck cancer and oncology at Johns Hopkins, found that a mouth rinse that captures genetic signatures common to the disease, might hold promise for screening those at high risk, including heavy smokers and alcohol drinkers.
In the study, the researchers 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 team 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. Tumour and blood samples were also collected.
The cellular mishaps occur when small molecules called methyl groups clamp on to the DNA ladder structure of a gene. In the grip of too many methyl groups, these genes can incorrectly switch on or off in a process called hypermethylation.
One panel correctly identified 66 out of 154 patients with the disease, and accurately ruled out the disease in 203 of 248 healthy subjects.
"Few tests can be perfect 100 percent of the time in identifying both normal and cancerous cells. 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," said Califano.
The researchers said that 'mass-methylation' of particular genes could lead to cancer. Methylation mistakes in other genes could be triggered simply by aging and amount to no more than fine lines and wrinkles.
"The challenge is to predict which hypermethylated genes are most specific to cancer," said Califano.
The study is published in Clinical Cancer Research.