Hand-held cellular telephones are used close to the head and there is concern that the radiofrequency (RF) energy produced by these devices may affect the brain and nervous system tissue in the head. Researchers have focused on whether RF energy can cause malignant (cancerous) brain tumors such as gliomas (cancers of the brain that begin in the glial cells, which are cells that surround and support nerve cells), as well as benign (non-cancerous) tumors, such as acoustic neuromas (tumors that arise in the cells of the nerve that supplies the ear) and meningiomas (tumors that occur in the meninges, which are the membranes that cover and protect the brain and spinal cord).
As a result of public and Congressional concern, DCEG investigators launched an early study and found no relationship between cell phone use and risk of glioma or meningioma (Inskip et al., NEJM 2001). A more recent Danish study linked a roster of 358,403 cellular phone subscribers with records in the Danish Cancer Register and did not observe evidence of increased risk of glioma or meningioma, either overall or for persons with subscriptions exceeding 10 years (Frei et al,, BMJ 2011). A recent multicenter, international study also reported no relationship between cell phone use and meningioma (Interphone, Int J Epidemiol 2010). However, the same investigators reported increased risk of glioma in a small group of the heaviest users, but no indication of increasing risk with increasing level or duration of use. In contrast, a Swedish study (Hardell et al., Int J Oncol 2011) reported substantially higher estimates of the risk of glioma in relation to cell phone use as compared to these other studies.
In a 2012 study (Little et al., BMJ 2012), DCEG researchers compared observed glioma incidence rates from cancer registries in NCI’s Surveillance, Epidemiology, and End Results program from 1992 to 2008, with projected rates based on risks observed in the Interphone study (2010) and the Swedish study (2011). Over the entire study period, glioma incidence patterns held roughly constant in all age groups. Projections based on the Interphone study, which found slight increases in risk among a small number of heavy users, were not statistically distinguishable from the observed U.S. rates. On the other hand, projections based on the Swedish study were at least 40 percent higher than, and incompatible with, the observed U.S. rates.
DCEG researchers have conducted a series of studies of time trends on U.S. incidence rates (Inskip et al., Neuro Oncol 2010, Little et al., BMJ 2012, Withrow et al. CEBP, 2018). This coincides with a period when there has been a substantial increase in usage of mobile phones in the U.S. population. They found little evidence for any change in rates of brain cancer overall or for glioma, the most common type of brain cancer. DCEG researchers plan to continue surveillance of glioma rates and changing usage patterns and technology of cell phones.
For more information, contact Martha Linet.