Link between cellphones, brain cancer 'inconclusive'

The most comprehensive study to date on the possible link between cellphone use and brain cancer has proven to be inconclusive, according to a Canadian scientist who contributed to the research.

The 10-year study, to be published Tuesday in the International Journal of Epidemiology, found most cellphone use didn't increase the incidence of meningioma or glioma -- two types of tumours -- in the more than 10,000 people examined.

But Dr. Jack Siemiatycki, an epidemiologist at the Centre hospitalier de l'Université de Montréal Research Centre and professor at the University of Montreal, says restricted access to participants compromised the validity of the research results.

"The findings (...) are ambiguous, surprising and puzzling," Siemiatycki said in a statement issued before the study's publication.

The study co-ordinated by the International Agency for Research on Cancer followed cellphone users, non-users, users who survived brain cancer and brain-cancer survivors who had never used cellphones.

Cellphone users showed no increase in brain cancer over the non-users. But heavy users -- those who used cellphones for more than 30 minutes per day -- had a greater risk of developing brain cancer than non-users.

Scientists are unsure what caused the discrepancy, but suspect faulty methodology is to blame, said Siemiatycki, one of 21 epidemiologists to work on the study.

Roughly 50 to 60 per cent of eligible subjects participated in the study, which may indicate the sample wasn't representative, he said. As a result, they may have provided an inaccurate portrait of cellphone usage among cancer patients and the healthy control group.

Siemiatycki said rigid constraints imposed by ethics committees forced researchers to recruit subjects through physicians, which may skew study results.

The researcher stressed that any risks of developing cancer through cellphone use would be small, and urged concerned consumers to use hands-free headsets as a preventative measure.

The study was performed by scientists in 13 countries, including Canada, the United Kingdom, France and Japan. The Canadian portion took place in Quebec, backed by the government-funded Canadian Institutes of Health Research.

Industry sources provided more than a quarter of the project's total funding of 19.2 million Euros.

CTV.ca News Staff