Genetic Test Helps Identify Those at High Risk for Mouth and Throat Cancer
April 25, 2001 -- When cancer develops in the mouth or throat, it's often bad news. One of the only clear signs that oral cancer might be on the horizon is the presence of white patches in the mouth or throat, but only a few of those white patches will lead to cancer. How to tell who is at risk? Once again, genetic research might have an answer.
Oral cancer is particularly deadly but fortunately also relatively rare, with about 300,000 new cases occurring every year. Rates are rising, however, for reasons that are not understood. The only known risk factors are smoking and drinking alcohol, but drug abuse may also play a role.
White patches in the mouth and throat are a common occurrence, but 5-15% of these patches belong to a specific type linked to cancer, and only 15-20% of this type actually results in oral cancer.
"We have come up with a method of identifying extremely high-risk patients for oral cancer at a very early stage," researcher Jon Sudbø, DDS, MD, PhD, tells WebMD." This gives us the opportunity to treat them at an earlier stage ... This will most likely increase the survival rate of these patients, which at the present time is very poor." Sudbø is from the department of oncology section for head and neck oncology at the Norwegian Radium Hospital Montebello in Oslo, Norway. His study is published in this week's issue of The New England Journal of Medicine.
"There's a real hope that we'll have better ways to predict who will develop oral cancer," says Scott M. Lippman, MD, who co-wrote an editorial to accompany this study. "These [white patches] are a common problem. Dentists see them all the time, and it's always a problem trying to decide how to manage them and who is at high risk. The criteria we use are very subjective and differ from doctor to doctor. This [new study] offers hope of developing some objective and very predictive information on who [will develop the disease]." Lippman is a professor of medicine and cancer prevention and chair of the department of clinical cancer prevention at M.D. Anderson Cancer Center in Houston.
Marshall Posner, MD, director of the head and neck oncology center at Dana-Farber Cancer Institute in Boston, says that it is not possible or necessary to closely monitor or treat everyone with white patches in their mouths. However, if a test like this can weed out, with reasonable accuracy, who is most likely to develop cancer, efforts can concentrate on monitoring those individuals, and those not at high risk can breathe easier. Posner was not involved in the research.
Sudbø and his colleagues identified 150 people who had the type of white patches in their mouth and throat that sometimes lead to cancer. The investigators conduced genetic studies on samples of these white patches and followed the individuals for over eight years. They found that the test, while not perfect, did a good job of predicting which participants would eventually develop cancer of the mouth and throat and which wouldn't.