Pooled analysis of two case-control studies on use of cellular and cordless telephones and the risk for malignant brain tumours diagnosed in 1997-2003.
OBJECTIVE
To study the use of cellular and cordless telephones and the risk for malignant brain tumours.


METHODS
Two case-control studies on malignant brain tumours diagnosed during 1997-2003 included answers from 905 (90%) cases and 2,162 (89%) controls aged 20-80 years. We present pooled analysis of the results in the two studies.


RESULTS
Cumulative lifetime use for >2,000 h yielded for analogue cellular phones odds ratio (OR)=5.9, 95% confidence interval (CI)=2.5-14, digital cellular phones OR=3.7, 95% CI=1.7-7.7, and for cordless phones OR=2.3, 95% CI=1.5-3.6. Ipsilateral exposure increased the risk for malignant brain tumours; analogue OR=2.1, 95% CI=1.5-2.9, digital OR=1.8, 95% CI=1.4-2.4, and cordless OR=1.7, 95% CI=1.3-2.2. For high-grade astrocytoma using >10 year latency period analogue phones yielded OR=2.7, 95% CI=1.8-4.2, digital phones OR=3.8, 95% CI=1.8-8.1, and cordless phones OR=2.2, 95% CI=1.3-3.9. In the multivariate analysis all phone types increased the risk. Regarding digital phones OR=3.7, 95% CI=1.5-9.1 and cordless phones OR=2.1, 95% CI=0.97-4.6 were calculated for malignant brain tumours for subjects with first use use <20 years of age, higher than in older persons.


CONCLUSIONS
Increased risk was obtained for both cellular and cordless phones, highest in the group with >10 years latency period.
Department of Oncology, University Hospital, 701 85, Orebro, Sweden. lennart.hardell@orebroll.se
Lennart
L
Hardell
Michael
M
Carlberg
Kjell
K
Hansson Mild
D001932:Brain Neoplasms / Q000175:diagnosis / Q000453:epidemiology* / Q000209:etiology; D016022:Case-Control Studies; D040421:Cell Phone / Q000145:classification / Q000706:statistics & numerical data; D004781:Environmental Exposure; D006801:Humans; D018570:Risk Assessment; D013689:Telephone / Q000145:classification / Q000706:statistics & numerical data