A new blood and saliva test that looks for traces of the human papillomavirus (HPV) can predict whether some people with oral cancers will have their cancer come back, early research suggests.
It helps to know as soon as possible that cancer has returned, because tumors that are caught early are easier to treat.
In the study, the researchers analyzed blood and saliva samples from 93 people with head and neck cancers; about 80 percent of these patients had cancers that tested positive for HPV. All of their cancers had previously been treated with surgery, radiation or chemotherapy.
The researchers looked for fragments of DNA from HPV-16, a strain of the virus that is strongly linked with head and neck cancer. The virus may be found in cancer cells that linger in the body after treatment, the researchers said. [Can Oral Sex Give You Cancer?]
Among people with HPV-positive tumors, the new test identified 70 percent of those whose cancer returned within three years, the researchers said.
"Until now, there has been no reliable biological way to identify which patients are at higher risk for recurrence, so these tests should greatly help [to] do so," study researcher Dr. Joseph Califano, professor of otolaryngology at Johns Hopkins School of Medicine, said in a statement.
Patients with head and neck cancer typically visit the doctor every one to three months during the first year after their diagnoses to check for cancer recurrence. But new tumors in the tonsils, throat and base of the tongue can be difficult to spot, and are often not detected early, the researchers said.
Still, more research is needed to confirm the findings, Califano said. Because HPV infection is common, the test may identify HPV infections that are not related to the cancer. "We can't be sure our test results are cancer-specific, and not due to other forms of HPV infection or exposure," Califano said.
The researchers are now looking for additional genetic markers that would increase the accuracy of their test.
The study is published today (July 31) in the journal JAMA Otolaryngology–Head & Neck Surgery.