Cellphones and Brain Cancer: A Doctor Weighs In
October 23, 2007, 11:18 am
From today’s mailbag, another response to Pogue’s Imponderables. I’m sure some readers still won’t be convinced–that’s why it’s an imponderable–but the two medical studies cited here are pretty darned convincing to me. (p.s… The excerpts from the studies are filled with medical jargon; I added the boldface formatting.)
One of Pogue’s imponderables was, “Do cell phones cause brain cancer?”
As a physician who has followed the published medical literature on this, I can tell you that the answer is no.
One problem is that as humans, when something bad happens to us, we blame something. So, if I get brain cancer — a very rare event indeed — I will blame using a cell phone. However, the reality is that I would have gotten brain cancer had I not used cell phones, if I in fact got brain cancer. The studies confirming that cell phones do not cause brain cancer examine the rate of brain cancer among a population of cell phone users and compare the rates to a population of non-users. Technically, a case-control study is often done.
Here are abstracts from 2 good scientific studies looking at the very question you posed.
Eur J Cancer Prev. 2007 Apr;16(2):158-64.
Use of mobile phones in Norway and risk of intracranial tumours.
Klaeboe L, Blaasaas KG, Tynes T.
The Cancer Registry of Norway, Institute of Population-based Cancer Research, Oslo, Norway.
To test the hypothesis that exposure to radio-frequency electromagnetic fields from mobile phones increases the incidence of gliomas, meningiomas and acoustic neuromas in adults. The incident cases were of patients aged 19-69 years who were diagnosed during 2001-2002 in Southern Norway. Population controls were selected and frequency-matched for age, sex, and residential area. Detailed information about mobile phone use was collected from 289 glioma (response rate 77%), 207 meningioma patients (71%), and 45 acoustic neuroma patients (68%) and from 358 (69%) controls. For regular mobile phone use, defined as use on average at least once a week or more for at least 6 months, the odds ratio was 0.6 (95% confidence interval 0.4-0.9) for gliomas, 0.8 (95% confidence interval 0.5-1.1) for meningiomas and 0.5 (95% confidence interval 0.2-1.0) for acoustic neuromas.
Similar results were found with mobile phone use for 6 years or more for gliomas and acoustic neuromas. An exception was meningiomas, where the odds ratio was 1.2 (95% confidence interval 0.6-2.2). Furthermore, no increasing trend was observed for gliomas or acoustic neuromas by increasing duration of regular use, the time since first regular use or cumulative use of mobile phones. The results from the present study indicate that use of mobile phones is not associated with an increased risk of gliomas, meningiomas or acoustic neuromas.
Am J Epidemiol. 2005 Mar 15;161(6):526-35.
Long-term mobile phone use and brain tumor risk.
Lönn S, Ahlbom A, Hall P, Feychting M; Swedish Interphone Study Group.
Institute of Environmental Medicine, Karolinska Institutet, Box 210, S-171 77 Stockholm, Sweden.
Handheld mobile phones were introduced in Sweden during the late 1980s. The purpose of this population-based, case-control study was to test the hypothesis that long-term mobile phone use increases the risk of brain tumors. The authors identified all cases aged 20-69 years who were diagnosed with glioma or meningioma during 2000-2002 in certain parts of Sweden. Randomly selected controls were stratified on age, gender, and residential area. Detailed information about mobile phone use was collected from 371 (74%) glioma and 273 (85%) meningioma cases and 674 (71%) controls. For regular mobile phone use, the odds ratio was 0.8 (95% confidence interval: 0.6, 1.0) for glioma and 0.7 (95% confidence interval: 0.5, 0.9) for meningioma. Similar results were found for more than 10 years’ duration of mobile phone use. No risk increase was found for ipsilateral phone use for tumors located in the temporal and parietal lobes. Furthermore, the odds ratio did not increase, regardless of tumor histology, type of phone, and amount of use. This study includes a large number of long-term mobile phone users, and the authors conclude that the data do not support the hypothesis that mobile phone use is related to an increased risk of glioma or meningioma.
Odds ratios below 1 are associated with reduced or no increased risk, and if the 95% confidence interval overlaps 1.0, there is no difference between cell phone users and non-users. Also, if cell phones caused brain tumors, one would expect to see more tumors on the side of the brain where the user tended to hold the phone and the part of the brain closest to the ear. No such association has been shown.
The occasional study will apparently show an association, but the statistical oddity is a reality. After all, someone wins the lottery with odds of 1 in many million. I am fully satisfied that mobile phone use does NOT cause brain cancer.
Brian Budenholzer, MD
Click here to view original article.
