Biggest study unable to link cell phone use, brain cancer

TORONTO - The world’s biggest study on links between cell phone use and brain tumours is inconclusive, says a Canadian scientist.

Jack Siemiatycki, professor and epidemiologist at the University of Montreal (UM) Hospital Research Centre, who collaborated on the Interphone International Study Group (IISG), says restricted access to participants compromised the validity of results of the study.

Over 10,000 people took part in the study: cell phone users; non cell phone users; cell phone users who survived brain cancer as well as brain cancer survivors who had never used cell phones.

“If we combine all users and compare them with non-users, the Interphone Study found no increase in brain cancer among users,” says Siemiatycki, who is with the UM Faculty of Medicine.

“In fact, surprisingly, we found that when we combine users independently of the amount of use, they had lower brain cancer risks than non-users,” adds Siemiatycki.

“However, the study also found heavy users of cell phones appeared to be at a higher risk of brain tumours than non-users.”

Why the discrepancy? Simply put, scientists are unsure. Attention has focused on the methodology of the study and, in particular, on the representativeness of the study subjects who participated.

With participation rates in the range of 50 percent to 60 percent of eligible subjects, it is possible that the participants did not provide an accurate portrait of cell phone usage among cancer cases and among healthy control subjects.

Siemiatycki argues this problem arose because of constraints imposed on researchers by ethics committees intended to protect potential research subjects, says a UM release.

“Ethics reviews are now so rigid that scientists from Canada, the United States and Europe are losing the kind of access to medical databases and to study subjects that is needed to conduct studies such as this one.”

The investigation was led by 21 epidemiologists from Australia, Canada, Denmark, Finland, France, Germany, Israel, Italy, Japan, New Zealand, Norway, Sweden and Britain.

These findings were published in the Tuesday issue of the International Journal of Epidemiology.