Dental X-rays could double the risk for the most common brain tumor, according to a study released Tuesday from scientists and doctors at Yale, Harvard and other prestigious institutions published in Cancer, a scientific journal of the American Cancer Society.
It sounds frightening — and there is no question it invokes a serious warning — but even those who carried out the research urge people not to overreact.
“Our take home message is don’t panic. Don’t stop going to the dentist,” said the lead author of the study Dr. Elizabeth Claus, a neurological surgeon at Brigham and Women’s Hospital in Boston and the Yale School of Public Health.
But people “should have a conversation with their dentist” about the need to use X-rays as little as possible to keep teeth healthy, Claus says. That’s a conclusion few would dispute, with or without the new study.
The tumor studied is meningioma, a type that is usually not malignant, meaning it can grow but not spread. To be sure, it can cause severe problems in some patients. But people with meningiomas often live long, healthy lives with no treatment, dying of some other cause. Doctors diagnose about 5,000 cases a year in the United States, about three times as often in women as in men.
Significantly, the study is the weakest type of epidemiology, a so-called “case control” study. The researchers interviewed 1,433 people diagnosed with meningioma and compared them with 1,350 people with no such diagnosis. The two groups were matched for age, gender, race, income and places of residence. In a tiny portion of the cases the researchers actually looked at dental records. But, most often, they asked the study subjects – whose average age was 57 — to recall their history of dental X-rays going back to childhood.