Researchers have found a significant link between the most common type of brain tumor in the United States—meningiomas—and a patient’s family history, suggesting that genetics play an important role in the development of the potentially debilitating lesions.
The Yale School of Public Health-led study compared 1,124 patients with the intracranial tumors with a nearly equal number of control subjects from different regions of the United States and concluded that an inherited gene (or genes) for meningiomas appears to be involved in the tumor’s onset.
Meningioma patients were 4.4 times more likely than their peers in the control group to report a first-degree family history (e.g., parents, offspring and siblings) of the tumor. Patients with a second-degree family history (e.g., grandparents, uncles and aunts and grandchildren), meanwhile, had an elevated but not statistically significant risk compared with their control peers.
During the five-year study, the researchers also examined a range of environmental, pathological and clinical factors that might be associated with the tumors. They found that the meningioma patients had greater exposure to ionizing radiation (which is suspected to cause tumors) through previous radiotherapy for illnesses such as leukemia and thyroid cancer. Meningioma patients were also more likely to have suffered from breast cancer, endometriosis and uterine fibroid tumors, suggesting a link between hormonal factors and the tumor.
“Identifying families who may share a genetic susceptibility to meningioma is one important way to try and identify genes for this tumor,” said Professor Elizabeth B. Claus, M.D. ’94, Ph.D. ’88, the study’s lead author and a neurosurgeon at Brigham and Women’s Hospital in Boston. “In our next research phase we plan to examine DNA obtained from such patients in an effort try to locate such genes.”
While the incidence of meningiomas is fairly common (accounting for about a third of all brain tumors) their origins are not well-understood. The study by Yale and collaborating researchers is the largest case-control study of meningioma ever undertaken. Claus said that further studies are needed to pinpoint the role of radiation, hormones and gene-environment interactions in the onset of the tumors.
Meningiomas take their name from the meninges, the membranes that envelop the brain and the central nervous system. The tumors can appear anywhere along these membranes and can grow to the size of a baseball, or larger. Symptoms vary widely and patients may experience headaches or vision problems. In some cases the tumor affects speech and motor control and can even cause cognitive changes, resulting in atypical behaviors and memory loss.
Women are twice as likely as men to be diagnosed with meningiomas and the risk increases with age. It is estimated that some 138,000 people in the United States have the disease and about 11,000 new cases are diagnosed each year.
Lisa Calvocoressi, Ph.D., an associate research scientist at Yale, co-authored the paper along with researchers from Texas, North Carolina, Massachusetts and California. The paper was published recently in the Journal of Neurosurgery.