Cellular Telephone Use and Brain Tumours
(Inskip et al, N. Engl. J. Med, 344, 79-86 (2001))
Results from a new study in the United States of America of brain tumours and the use of mobile phones were released prior to publication of the final version in the New England Journal of Medicine on 11 January 2001. In common with a similar American study published recently, the new study does not show an association between brain tumour risk and the use of mobile phones during the previous few years. Further research is required to evaluate any longer-term effects and to study more frequent users.
As in an earlier study by Muscat et al (JAMA, 284, 3001-7, 2000), the new study is based on brain tumour cases and controls selected from hospitals in the United States of America. Inskip et al collected information for 782 cases and 799 controls on the use of mobile phones and on factors such education and income that might be correlated with risks. The number of people in this study was greater than that in the earlier study. The proportion of regular mobile phone users was also slightly higher in the new study, although it was still low in absolute terms (about 20%).
No association was found between brain tumour risk and mobile phone use, according to either frequency or duration of use. There was also no association between the side of the head on which the phone was held and the side of the head on which the tumour occurred. Furthermore, risks were not raised for particular types of tumours, nor according to the lobe of the brain that was affected.
In view of the similar design, the new study shares many of the strengths and weaknesses of the earlier study by Muscat et al , as described in NRPB Response Statement R5/00. In particular, both the proportion of mobile phone users and their average duration of use are low compared with current values, reflecting the fact that most of this use took place in the early and mid-1990s. Furthermore, most of the mobile phones in this study were analogue and operated at frequencies of around 800 to 900 MHz, whereas mobile phones in the UK are now mostly digital and operate at either 900 or 1800 MHz. In addition, some types of tumours may take many years to develop, and research that allows for potentially long induction periods would be desirable. These points will be addressed in an international study, coordinated by the International Agency for Research on Cancer, for which data collection is commencing. This study will include data from 13 countries, including the UK, with first results expected in 2004.
NRPB Response Statement R2/01
11 January 2001
Last updated 11th January 2001