NEW YORK, December 20, 2000 - With more than 86 million American cellular phone users reported in 1999 and the number still increasing, there has been growing concern about the risk of developing brain cancer from radiofrequency signals given off by handheld cellular phones. A case-control study of 891 people who regularly used a cellular phone showed no statistical association between the amount of cell phone usage and the likelihood of developing brain cancer. Researchers from the American Health Foundation and Memorial Sloan-Kettering Cancer Center and four United States medical centers reported their findings in the December 20 issue of the Journal of the American Medical Association.
"The recent phenomenon of widespread use of cellular phones had been a suspected risk factor for the development of brain cancer and needed to be clarified by a study," explained Joshua Muscat, MPH, of the Division of Epidemiology of the American Health Foundation and the study's first author. "The data showed no correlation between the use of cell phones and the development of brain cancer. In addition, there was no association between the amount of cell phone usage and brain cancer."
In a retrospective, case-control study, 469 men and women diagnosed with primary brain cancer and 422 people without brain cancer were interviewed between 1994 and 1998 using a structured questionnaire. They were asked which type of cell phone (manufacturer) they used, the usage per month in minutes and hours, the year of first use, and the number of years of usage. In addition, an estimated monthly phone bill was ascertained. The patients, aged 18 to 80, were scrupulously matched to the control group by age, sex, race, years of education, and occupation.
The usage reported for cancer patients and the control group was not statistically significant. The median monthly use was 2.5 hours for cases with cancer and 2.2 hours for the control. The mean duration of use was 2.8 years for brain cancer patients and 2.7 years for the controls.
"Because 85 per cent of people in the study reported extending the antenna during calls, we might have expected to find a disproportionate cluster of tumors behind the eye and the ear on the side the cell phone was used since radiation emission is highest at the antenna," said Mark Malkin, MD, a neuro-oncologist at Memorial Sloan-Kettering Cancer Center and study co-author. "In fact we found no link between cell phone usage and temporal lobe tumors, nor was there any association between handedness and tumor location."
The study was conducted through interviews of patients at Memorial Sloan-Kettering Cancer Center, New York University Medical Center, Columbia Presbyterian Hospital, Rhode Island Hospital and Massachusetts General Hospital. Muscat and the late Ernst L. Wynder, MD designed the study and conducted the statistical analysis under the auspices of the American Health Foundation.
Based on all available data including studies by other groups, the researchers believe that extended use of cellular phones does not appear to cause brain cancer. However, further research is indicated as this study covers people who have mostly used analog cellular phones for a relatively short period of time (two to three years). As people continue to use cell phones for extended durations, the long-term health effects, if any, need to be monitored.
This project was supported by a contract from Wireless Technology Research LLC and Public Service Health grants from National Cancer Institute.
CONTACTS:
Memorial Sloan-Kettering Cancer
Center
Joanne Nicholas
212 639-3573
American Health Foundation
Monica Bynoe
212 551-2546
Journal
JAMA