Johansen C, Boice JD Jr, McLaughlin JK, et al (2002)

This group previously reported a cohort study that examined cancer rates in cellular telephone subscribers. They now compare the incidence rates of malignant melanomas of the eye in Denmark from 1943 through 1996 with numbers of telephone subscribers. They found that the age-standardized rates for the cancers remained fairly stable in 5-year periods, which contrasted with the rapid increase in phone subscribers from 1982 to 1996.

The authors state that their results are different from a German case-control study (Stang, 2001 -see summary). However, the present study design is entirely different. An ecological study such as this is a weak type of design, since it does not examine details of exposure or disease occurrence in individuals. The authors do mention, however, that in their cohort study only eight cases of ocular cancer were seen compared with 13.5 expected from the population studied.