Do cell phones cause cancer?

I've always doubted claims about cellphones and cancer because of the latter should require a long latency, and cell phone use is a recent development. Early results from a large collaborative study are, however, beginning to suggest a trend...

Interphone researchers are pooling and analyzing the results gathered from studies on 6,400 tumors sampled from patients in 13 countries... people who use cellphones regularly are 50 percent more likely than non-users to develop brain tumors. And a joint Interphone analysis from the U.K., Denmark, Norway, Sweden and Finland reported a 40 percent increase in tumor risk in people who use cellphones for more than a decade; the study found no discernable risk for people who have used cellphones for fewer than 10 years.

Note that's not a study of 6,400 people - it's a study of 6,400 cases of brain cancer, which is a relatively uncommon disorder.

Image credit to Gizmodo - I interpret it as a commentary on where people should store cell phones while driving a car...