No link seen between cellphones, brain tumor


People who have used a cellphone for more than a decade do not appear to be at increased risk of a type of non-cancerous brain tumor, a new study suggests.
Looking at data on more than 2.8 million Danish adults, researchers found that those who’d used a cellphone for 11 to 15 years were no more likely than newer users or non-users to develop an acoustic neuroma. Acoustic neuromas, also known as vestibular schwannomas, are non-cancerous, slow-growing tumors that form on the main nerve running from the inner ear to the brain.
They can cause symptoms like ringing in the ears, dizziness and balance problems; in a small number of cases, they can grow large enough to press against the brain and become life-threatening. Although they are not cancerous, acoustic neuromas are considered important in the ongoing question of whether cellphones carry any brain cancer risk.
“Of interest is that acoustic neuromas grow in the area of the brain where greater energy emitted from the cellphones is absorbed, compared to other areas of the brain,” explained Dr. Joachim Schuz, who is with the World Health Organization’s International Agency for Research on Cancer (IARC) and led the new study.
So it might be expected that if cellphones were a cause of brain tumors, people who’ve used them for a long time might have an increased risk of acoustic neuroma — especially on the side where they typically hold their phone. But that wasn’t the case, Schuz’s team reports in the American Journal of Epidemiology.
Among the nearly three million Danish adults they had data for, just over 800 were diagnosed with acoustic neuroma between 1998 and 2006. And those who’d used cellphones the longest — at least 11 years — had no greater risk than shorter-term users or non-users. On top of that, Schuz said in an email, there was no indication that long-term cell users had larger-than-expected tumors. Nor did they have a tendency to develop acoustic neuromas on the right side, where most held their phone. Still, the findings are not the final word on cellphones and acoustic neuroma.
One problem, according to Schuz, is that even long-term cellphone users had not been using their devices all that long. Acoustic neuromas generally grow slowly, and years may pass between a person’s first symptoms and a diagnosis, Schuz noted.