Mobile phones and cancer: Study says ‘no’, news reports say ‘yes’…

Ahead of a landmark study, newspapers all around the world have carried news reports warning of the terrible risk faced by mobile phone users.

The story behind the story is worth a few words. Firstly, the study seems to say the opposite to what all these reports claim. Secondly, the study was under embargo until the time this post was published (9.30am, Sydney time), a good 48 hours after the publication of some of these new reports.

The UK media — broadsheet and tabloid alike — have led the sensationalist charge.

The TimesOnline says:

PEOPLE who use their mobile phones for at least 30 minutes a day for 10 years have a greater risk of developing brain cancer, a landmark study has found.

Here in Australia, the national broadsheet, The Australian, led their story with:

A LONG-awaited international study of the health risks of mobile phones has linked extended mobile phone use to an increased risk of developing brain tumours.

All this is a little surprising since when you actually look at the study, it says that “overall, no increase in risk of glioma or meningioma was observed with use of mobile phones“.

Professor Bernard Stewart, the Scientific Advisor to Cancer Council Australia, commenting on the research says that the study “has found no evidence that mobile phones cause brain cancer, consistent with previousresearch in this area”. He continues:

We already know that mobile phones are not able to damage genetic material (DNA) in cells directly and so cannot produce cancer-causing mutations. However, there have been concerns that electromagnetic fields from mobile phones may be able to increase the rate of cancer development by influencing cancer promotion or progression. The Interphone study has found no evidence supporting this theory.

Some questions do still remain. As Professor Stewart says:

However, it did find that in patients with glioma, based on heavy phone use, the tumour was likely to be on the same side of the head as the mobile phone. While this does not prove a link between mobile phones and cancer, it does merit further research.

Also, other experts have pointed out that the study did not have much data on the use of mobile phones by children or on very heavy phone users. Nevertheless, stories saying that the study established a link are far from justified.

Indeed, it’s hard to imagine what more the researchers could possibly have said to avoid these kind of headlines: Not finding evidence of a link is as good as it gets insofar as establishing that there is no link. With epidemiological studies, you can’t prove that there is no link other than by looking for evidence of one, and not finding it.

In addition to the questionable reporting of the results, news outlets were reporting on the findings a good 48 hours ahead of the lifting of the embargo. I’m not quite sure what to think about this.

I decided not to post info about the article, even though it was freely available [pdf] to anyone with an internet connection. A number of news outlets initially weaseled their way out of actually breaking the embargo by reporting on reports of the study… But once they opened the lid, every other news outlet assumed it was ok for them to report on the study itself.

The whole notion of embargos makes me feel a little uneasy. I feel that it drives a wedge between two principles of journalism… But perhaps that whole issue is best saved for another post.

This post was chosen as an Editor's Selection for Elisabeth Cardis (2010). Brain tumour risk in relation to mobile telephone use: results of the INTERPHONE international case–control study International Journal of Epidemiology, 1-20 : 10.1093/ije/dyq079