A decade after cellphone use became widespread, a large study in the United Kingdom of 966 people aged 18 to 69 who were diagnosed with gliomas - the most common kind of brain cancer - has shown that mobile phone use does not increase the risk of this tumor. The case-control study, the first in the UK to study the relationship between cellular phone use and the risk of gliomas, was being published Friday morning on the on-line edition of the British Medical Journal (BMJ). The four-year study by researchers at the Universities of Leeds, Nottingham and Manchester and the Institute of Cancer Research in London found those who had regularly used a cellular phone were not at a greater overall risk of developing this type of tumor. No connection was found between the risk of glioma and the time since first use of a cellphone, lifetime years of use and cumulative number of calls and hours of use. Risk was not linked to phone use in rural areas, which was found to be associated with an increased risk in an earlier Swedish study. The researchers said that a significantly increased risk was found for tumors that developed on the same side of the head as the phone was reported to have been held - but this was mirrored by a decrease in the risk on the opposite side of the head, making it difficult to interpret as a real effect. This finding may be due to people with glioma brain tumors linking cellphone use to the side of the tumor and therefore overreporting the use of a phone on the same side as their tumor. This results in underreporting use on the opposite side of the head, say the authors. Early mobile phones were designed to use analogue signals and emitted higher power than current digital phones, but the study showed no increased risk of gliomas with the use of analogue phones.