Study Shows Cancer Linked to Mobile Phones, But Authors Spin the Results

Recent media reports falsely claim that the Interphone study shows no increase in cancer from mobile phone use. They’re merely reporting what the authors of the study claimed, without much critical thinking about the results. Had they looked into it, they might have realized that the conclusion is a slippery misrepresentation of the actual results.

The Interphone Study

The study, called Interphone, looked at people from around the world, aged 30 to 59, who’d been diagnosed with either a glioma, a type of brain cancer, or a meningioma, a noncancerous tumor, between 2000 and 2004. Subjects were interviewed about their mobile phone usage and a range of demographic, medical history, and radiation exposure questions.

A total of 4,301 glioma cases and 3,115 menigioma cases were found. However, significant numbers refused to take part in the study, and others could not because of their illness, death, their doctors’ refusal to be involved, or simply inability to contact them. 2,708 (63.0% of the total) glioma and 2,409 (77.3% of the total) meningioma cases were interviewed. The glioma cases were matched with 2,662 controls and the meningioma cases were matched with 2,972 controls.

Interphone compares people with glioma (cancerous tumor) or meningioma (non-cancerous tumor) with equivalent people without tumors.

Study Flaws

The proportion of people with gliomas and meningiomas who were not involved in the study is significant: 37% of glioma cases and 22.7% of meningioma cases. An even greater percentage of control subjects, 47%, refused to participate. This could have biased the results.

In fact, a bit of thought about this concern should show that it most likely did affect the results. Note that many of those who did not take part were too ill or dead. In other words, the people with the worst cases of cancer were not counted in the results.

The study noted that prodromal (early stage) symptoms of disease may have stopped or reduced the use of mobile phones, thus affecting the results.

The length of time subjects had used mobile phones before tumor diagnosis was generally 2-10 years. Very few had used them more than 12 years.

Interphone’s Official Conclusion

With one exception, the study concluded that there was no increase in tumors in relation to mobile phone use. However, the results were rather complex, and two highly significant results completely contradict the official conclusion.

The Downplayed Results

The study’s authors did not point out highly significant findings—ones that completely contradict the official conclusion:

• Cancer rates were higher in people who used mobile phones on only one side of the head. Those who switched sides had lower rates.
• Cancer rates were higher in the longest term mobile phone users.
• Cancer rates were highest in the heaviest users. (The authors attributed this result to faulty memories on the parts of these users.)

One of the study’s authors, Professor Anthony Swerdlow of the Institute of Cancer Research in the UK, stated of the results:

It is impossible to say there is no risk whatsoever…the study has not shown a raised risk of brain tumors and it has certainly not shown that mobile phones cause brain tumors.

When cancer rates are higher in the longest term mobile phone users, higher in the heaviest users, and those who use the phone only on one side of the head, it’s difficult to see how the authors could possibly have found no connection between mobile phone use and cancer.

These results were found in spite of reported mobile phone usage that is low by today’s standards, and of a duration that is brief enough to limit the likelihood of a connection between brain cancer and any cause. It’s generally believed to be a slow-developing cancer, so any study that doesn’t last longer than ten years is unlikely to turn up the truth.

Yet, in spite of these limitations, important connections between mobile phone use and increased cancer rates were noted.

The only question is: Why would the authors spin the results the way they did?

Follow the Money: Funding Sources for the Study

The study was rife with conflicts of interest. It was funded heavily by the industry it was purportedly investigating. Funding came from the Mobile Manufacturers’ Forum, GSM (Global System for Mobile Communications), and the Canadian Wireless Telecommunications Association.

Other support was received by an Australian organization that is funded by mobile phone license fees. Part of the UK funding came from the UK Network Operators, which includes four of the largest mobile phone companies in the country. Two of the authors admit to having a financial interest in mobile phone companies.

The Bottom Line

The bottom line, as ever, is the bottom line. The Interphone study is seriously flawed. A large percentage of potential subjects did not take part, and these tended to be the sickest people. Those who did agree to take part were generally not long term users, but the ones who’d used mobile phone the longest were most likely to have gliomas, and those who used the phones on only one side of the head were also more likely to suffer brain cancer.

If the overall results showed no increase in cancer, it could be that an apparent temporary protective benefit was gained—as the authors noted—at the expense of more cancer after a certain period of time. In fact, the results seem to support that notion.

The authors’ conclusion, that the study showed no connection between mobile phone use and brain cancer, does not correlate with the actual results. However, the data is suggestive that there is a connection.

On one point, the authors are right on target: The study most assuredly does indicate a need for further research. A good point to start is a reanalysis of Interphone’s data by unbiased investigators.

Interphone showed increased cancer in the heaviest users. The authors tossed this off as an anomaly. However, these “heavist users” included anyone who spends more than 30 minutes a day on a mobile phone. That’s hardly unusual nowadays, with people who spend their entire working days with mobile phones pinned to their ears. The authors’ claimed results are, at best, disingenuous.

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