WEDNESDAY, July 27 (HealthDay News) -- Children who use cell phones don't seem to face an increased risk of brain cancer, compared to children who don't use them, a new study contends.
But, the study authors and other experts cautioned that more research is needed.
With the increase in cell phone use among kids, some worry that radiation from the devices can increase the risk for brain tumors. Children's brains are still developing, and because their heads are smaller radiofrequency electromagnetic fields may penetrate areas deeper in the brain, some researchers say.
"The [study] results are reassuring, given the widespread use of mobile phones by children and adolescents," said lead author Martin Roosli, an assistant professor at the Swiss Tropical and Public Health Institute in Basel, Switzerland.
"However," he added, "uncertainties remain regarding long-term use. Thus, further careful monitoring whether brain tumor incidence is increasing in this age group is important."
The findings were published July 27 in the Journal of the National Cancer Institute.
For the study, Roosli's team collected data on 352 children and adolescents aged 7-19 with brain cancer, and compared them to 646 similar children who did not have brain cancer. The children came from Denmark, Norway, Sweden and Switzerland. The researchers also interviewed the children and asked them about their cell phone use.
The researchers found that children with brain tumors didn't use cell phone more than those without tumors. Specifically, 75.3 percent of the children with brain tumors said they had used a cell phone more than 20 times before being diagnosed with their tumor. Among those children without cancer, 72.1 percent reported similar cell phone use.
Among children with tumors, 55 percent said they used a cell phone regularly, compared to 51 percent of children without tumors.
Also, there was no increase in the risk for tumors in the area of the brain receiving the most radiation from cell phones, the researchers said.
"However, people who are concerned might consider using cell phones with low radiation emissions or they might consider using an ear piece or using the phone's speaker," Roosli said.
These findings probably won't quell the debate about the potential risk of brain cancer from cell phones.
In May, a panel of experts at the World Health Organization (WHO) said cell phones may cause brain cancer. After reviewing dozens of studies on the subject, the experts classified cell phones as "possibly carcinogenic to humans" and placed them in the same category as the pesticide DDT and gasoline engine exhaust.
Commenting on the new study, John D. Boice Jr., of the International Epidemiology Institute and co-author of an accompanying editorial in the journal, said that "the occurrence of a brain tumor in a child is a devastating diagnosis. Research into the causes of brain tumor and improved treatment regimens should continue. However, there should not be a concern that using a cell phone has caused brain cancer."
There's been no evidence from population data on brain tumor occurrence over the past 20 years to indicate that rates are increasing among children or adults, which would be expected if cell phone use caused brain tumors, Boice said.
"The recent announcement by the WHO has caused widespread confusion and unnecessary alarm, in large part due to a misunderstanding of the category 'possibly carcinogenic,' which is for agents for which there is 'limited evidence for carcinogenicity,'" he explained.
Elizabeth Ward, national vice president of intramural research at the American Cancer Society, called the new research "a very important study that has a great number of strengths, including a population-based contemporary sample and a high participation rate."
"But, as in most areas of epidemiology where complex risk factors are studied, additional studies are needed to develop conclusive evidence about potential risks of mobile phone use. It is important that additional studies be done in children, adolescents and young adults with early life exposure to mobile phones," she added.
For more on brain cancer, visit the U.S. National Library of Medicine.
SOURCES: Martin Roosli, Ph.D., assistant professor, Swiss Tropical and Public Health Institute, Basel, Switzerland; John D. Boice Jr., Sc.D., International Epidemiology Institute, Rockville, Md.; Elizabeth Ward, Ph.D., national vice president, intramural research, American Cancer Society, Atlanta; July 27, 2011, Journal of the National Cancer Institute
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