- Baltimore, MD
- Johns Hopkins news release
New Saliva Test Helps Detect Head and Neck Cancer in Early Stages
A new noninvasive DNA test has been developed that simply swabs the mouth to diagnose head and neck cancer. The test could improve early detection of head and neck cancer, which would improve patient’s survival and reduce the need for radiation therapy, chemotherapy and extensive surgery.
“The test has been developed to detect head and neck cancer at an early stage,” said David Sidransky, MD, director of head and neck cancer research at Johns Hopkins University in Baltimore, one of the researchers studying the new test.
“If you look at oral cancer, about half of them are diagnosed at very advanced stages, so clearly, they’re not being diagnosed at an early stage.”
The test works by first swabbing the entire area of the inside of the cheeks and the back of the tongue. Then the patient rinses with a solution and spits it out. Then the swab and the rinse are mixed together so as many cells as possible are obtained, he added. “The more cells we have, the better the genetic test is,” Dr. Sidransky explained.
First Phases of Testing
In the first phase of the study, Dr. Sidransky and colleagues tested cells from the saliva of 21 patients who already had head and neck cancer and 22 cancer-free patients. They found genetic “clonal markers” in the cells of 71 percent of cancer patients compared to none of the cancer-free patients, indicating the test was accurate in detecting the markers. Dr. Sidransky said in further studies of additional patients, 80 percent of cancer patients have been found to have the clonal markers.
“These are just feasibility studies to see how well the test is performing,” Dr. Sidransky explained. Once the clonal markers are found, the test is 100 percent effective, he added. “The specificity or how specific the test is once you find [the marker] is 100 percent. That means that when we find it, we only find it in patients with cancer.”
About 40,000 Americans are expected to develop head and neck cancer this year, with as many as 60 percent of patients relapsing within five years of treatment. So the next step in the research process is to use the test on cancer patients over time to determine cancer recurrence rates, Dr. Sidransky added. He predicts the test could be used by dentists to screen for head and neck cancer, particularly in smokers, who are at greatest risk of developing this disease.
Dentists May Do Screening
“We need dentists to do the screening eventually because they are the ones who are going to see patients for their normal oral exams,” Dr. Sidransky said. “They will be in the best position to take the saliva.”
Promising Area of Research
Waun Ki Hong, MD, the chairman of the department of thoracic head and neck oncology at M.D. Anderson Cancer Center in Houston, is familiar with the study.
“I think this is a highly promising area of research for the early detection of cancer and also [for] the molecular detection of recurrent tumors,” said Dr. Hong. “This technique is a fairly noninvasive test, you don’t have to do any biopsies. If you find [head and neck cancer] in the early stages before patients present with a tumor, it can be treated without disfiguring surgery.”
The test may be commercially available in two to three years.