The latest and longest study of the potential link between cellphone use and brain cancer risk has found no increased incidence of brain tumors or any other malignancies among longtime cellphone subscribers.

Conducted by the Institute of Cancer Epidemiology in Copenhagen and published Thursday in BMJ, the research tracked data over 18 years for 358,403 Danish-born people age 30 and older. That group was subdivided into subscribers and non-subscribers of mobile phones before 1995.

From 1990 to 2007, tumors of the central nervous system were reported in 10,729 cases, the study said. As with earlier Danish research on which this study builds, the new study found no increase in incidence of any cancer among cellphone subscribers, even among those who had subscribed the longest (13 years or more). In particular, no rise in glioma in the temporal lobes, the part of the body most directly exposed to cellphones, was detected among long-term subscribers versus shorter-term subscribers.

The authors noted that long-term subscription to a mobile phone contract does not equal long-term use of a mobile phone. They said that future research should examine actual cellphone use, not just duration of subscription to a cellphone plan.

A panel of experts organized by the World Health Organization reported in May that cellphone radiation is “possibly carcinogenic” to humans.