Cell Phones and Brain Tumors - Is There a Link?
- Created on June 1st, 2010
- By The National Cancer Institute
Study Finds No Overall Increased Brain Tumor Risk from Cell Phones
A large international study has found no overall increased risk of two types of brain tumors among people who use mobile phones. The case-control Interphone study analyzed data on cell phone use from more than 5,000 patients in 13 countries who had either glioma or meningioma and from matched comparison groups.
No evidence of overall increased risk was found when the results were analyzed according to increasing numbers of calls, duration of call time, or time since a person started to use cell phones. For a very small proportion of persons who were heavy users, the researchers found an increased risk for glioma, but the results were inconclusive.
"An increased risk of brain cancer is not established from the data from the Interphone study," said Dr. Christopher Wild, director of the International Agency for Research on Cancer, which coordinated the study. He noted, however, that further research was warranted because of the result involving heavy users and because usage patterns continue to change, particularly among young people.
The findings, published online May 18 in the International Journal of Epidemiology, are consistent with the majority of published reports on cell phones and malignant or benign brain tumors. No previous study, however, has included as many patients with brain and central nervous system tumors who had histories of cell phone use, particularly long-term and heavy users of mobile phones, as this one.
"Interphone will be the most definitive study of cell phones and risk of brain and central nervous system tumors for some time to come," said Dr. Martha S. Linet, chief of the Radiation Epidemiology Branch in NCI's Division of Cancer Epidemiology and Genetics. She praised the investigators for going to great lengths to understand and address the methodological challenges in studying cell phone usage in patients with cancer.
The study focused on patients who developed brain tumors between age 30 and 59. A Nordic study is expected to provide some results on children in the next few years, Dr. Linet said. Plans are also under way for a study called MOBI-KIDS, which would evaluate risk from new communications technologies, including cell phones, and other environmental factors in people between age 10 and 24.
Cell phones emit a form of radiation known as radiofrequency energy, but how this affects cancer risk is not clear. Dr. Linet noted that although cell phone usage has been increasing, exposure to radiofrequency energy from cell phones to individuals has declined steadily. This is in part because technology has improved and because there are more cell phone towers, which reduces the amount of radiofrequency energy exposure to the user. The farther a cellular telephone is from the base station antenna, the higher the power level needed to maintain the connection.
Dr. Linet and her colleagues have been monitoring the incidence of brain cancer in the United States during the rise in cell phone usage. "We have not seen an increase in brain tumor incidence that one might expect if there were an increased risk of cancer from cell phone usage," she said. "This is an important public health message." (For more information, see NCI's Cellular Telephone Use and Cancer Risk Fact Sheet.)