In the latest study from Sweden, researchers looked at more than 1,400 adults aged 20 to 80 who had been diagnosed with a malignant or benign brain tumour between 1997 and 2000. The brain cancer patients were compared with a similar number of healthy adults living in the same area. Each group was asked to recall their daily use of mobile and cordless phones, according to a report in the journal of Occupational and Environmental Medicine.