Unexpected results from world's largest study of mobile phone cancer risk

You've probably heard that using a cell phone will give you brain cancer. Is it true? Scientists just completed a massive, international study of the connection between brain cancer and mobile phone use.

It's long been debated in and out of the scientific community whether the microwaves emitted by mobile phones can cause brain cancer. The new study, called INTERPHONE, is the largest of its type, and was organized by a division of the World Health Organization. Researchers wanted to find out if there was a link between two common types of brain cancer - glioma and meningioma - and mobile phone use. They studied 2,708 people with glioma, 2,409 with meningioma, and 7,658 people in a control group. Their subjects came from 13 different countries.

Unfortunately, results were both inconclusive and kind of weird.

According to Nature:

Regular phone use seemed to actually decrease the risk of the cancers when the numbers were crunched. But the 10% of participants who reported the greatest amount of time spent on their mobile phones seemed to have a 40% increased risk of glioma. However, the study points out that there are reasons to doubt these apparent associations.

On completing their analysis, the researchers found that being a regular user of a mobile phone seemed to reduce the risk of glioma or meningioma by around 20%. But Anthony Swerdlow, an epidemiologist at the Institute of Cancer Research in London who was involved in the UK arm of the study, says that this result is highly likely to be down to problems that were inherent in the study design.

"We have evidence that the people who refused to be controls are people who didn't use phones," says Swerdlow. This meant that the control group, consisting of people without cancer, was rather skewed, appearing to have more mobile-phone use than would be found in a representative sample from the general population. "The controls were over-represented with phone users," he adds.

Equally, some of those individuals in the top 10% of reported phone usage gave what Swerdlow calls "incredibly implausible values", such as an average of 12 hours of mobile use per day, every day.

In other words, it's hard to conduct a scientific study that's based in part on self-reported behaviors. Probably a better way to do this research would be to conduct a 10-year study of people who agree to use phones that track the amount of time they spend phone-to-ear.

Until researchers are able to get better data, it's impossible to say whether there is a link between mobile phone use and brain cancer. That's not cause for relief. It's cause for more research.

via Nature