Brain tumour studies
 All the independently-funded studies we are aware of which included longer-term users (10 years or more) found an assocation between mobile/cordless phone use and some brain tumours.
This is a list of most of the scientific studies investigating the link between mobile/cordless phone use and brain tumours (and some other head/neck tumours). We have done our best to ensure the list covers most or all of the main studies and that our summaries are fair and accurate. (Click on the study for more details):
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Glossary...
Studies including data on longer term users (more than 10 years’ use):
Lennart Hardell, Michael Carlberg. Mobile phones, cordless phones and the risk for brain tumours. Department of Oncology, Örebro University Hospital
Regarding astrocytoma found highest risk for ipsilateral mobile phone use in the >10 year latency group, OR=3.3, 95% CI=2.0-5.4 and for cordless phone use OR=5.0, 95% CI=2.3-11. In total, the risk was highest for cases with first use 10 year latency, for mobile phone OR=3.0, 95% CI=1.4-6.2 and cordless phone OR=2.3, 95% CI=0.6-8.8.
Overall highest OR for mobile phone use was found in subjects with first use at age less than 20 years, OR=5.0, 95% CI 1.5-16. The annual age-adjusted incidence of astrocytoma for the age group >19 years increased significantly by +2.16%, 95% CI +0.25 to +4.10 during 2000-2007 in Sweden in spite of seemingly underreporting of cases to the Swedish Cancer Registry.
Review yielded a consistent pattern of an increased risk for glioma and acoustic neuroma after >10 year mobile phone use. Authors conclude that current standard for exposure to microwaves during mobile phone use is not safe for long-term exposure and needs to be revised.
Ipsilateral (on the same side) use for more than 10 years showed a significantly increased risk for glioma (OR 2.0, CI 1.2-3.4) and acoustic neuroma (OR 2.4, CI 1.2-5.3). The authors concluded that the meta-analysis gave a consistent pattern of association between mobile phone use for more than 10 years and ipsilateral glioma and acoustic neuroma. Limitations (according to author): The results for mobile phone use for more than 10 years are based on low numbers.
Increased risk associated with use for 10 years or more with consistent pattern of increased risk for acoustic neuroma and glioma. The risk is highest for ipsilateral exposure. An association with acoustic neuroma was found in four studies in the group with at least 10 years’ use of a mobile phone. No risk was found in one study, but the tumour size was significantly larger among users. Six studies gave results for malignant brain tumours in that latency group. All gave increased odd ratios (OR), especially for ipsilateral exposure. In a meta-analysis, ipsilateral cell phone use for acoustic neuroma was OR = 2.4 (95% CI 1.1 to 5.3) and OR = 2.0, (1.2 to 3.4) for glioma using a tumour latency period of 10 years.
No increased risk established (OR=0.67).
Problems with the Interphone multinational study...
Found an increased risk for tumour ipsilateral to side of phone use was found for more than 10 years of mobile phone use
Problems with the Interphone multinational study...
PubMed report...
Found a slightly increased risk (OR 1.25; CI: 1.01-1.54) for patients with 10 or more years of exposure was observed.
PubMed report...
Analysis restricted to regular users or to conditions that may yield higher levels of exposure (e.g., heavy use in rural areas) showed consistently elevated risks. For ipsilateral use, the odds ratios in the highest category of cumulative number of calls and call time without use of hands-free devices were 1.58 (95% confidence interval: 1.11, 2.24) and 1.49 (95% confidence interval: 1.05, 2.13), respectively. Author’s conclusions: Based on the largest number of benign PGT patients reported to date, our results suggest an association between cellular phone use and PGTs.
PubMed Report...
Problems with the Interphone multinational study...
Regular cell phone use was not associated with an increased risk of neuroma (OR=0,92; 95% confidence interval=[0.53-1.59]), meningioma (OR=0,74; 95% confidence interval=[0.43-1.28]) or glioma (OR=1.15; 95% confidence interval=[0.65-2.05]). Although these results are not statistically significant, a general tendency was observed for an increased risk of glioma among the heaviest users: long-term users, heavy users, users with the largest numbers of telephones. Author’s conclusion: the results, suggesting the possibility of an increased risk among the heaviest users, need to be verified in the international INTERPHONE analyses.
Problems with the Interphone multinational study...
The consistent finding for all studied phone types was an increased risk for brain tumours, mainly acoustic neuroma and malignant brain tumours. Using a latency period of > 10 years ORs increased especially for astrocytoma grade III-IV. Regarding analogue phones OR increased with latency period and was highest in the category with latency period > 15 years yielding OR = 3.5, 95 % CI = 1.4–10. Increased risk was also found for digital cellular telephones and cordless phones. However, in the multivariate analysis only analogue phones were significant risk factors with OR 2.2, 95 % CI 1.3–3.8 using > 10 year latency period. Found some indication of higher risk for brain tumours in persons with first use of cellular or cordless phones before the age of 20 years compared with older ages. The increased risk for users >15 years OR 3.5 is significant
In the multivariate analysis, a significantly increased risk of acoustic neuroma was found with the use of analogue phones. The highest OR was found for analogue phones with a latency period of >15 years: OR=3.8, 95% CI=1.4-10.
Read analysis...
Schüz J et al. (2006): Cellular phones, cordless phones, and the risks of glioma and meningioma
Overall use of a cellular phone was not associated with brain tumor risk; the respective odds ratios were 0.98 for glioma and 0.84 for meningioma. Among persons who had used cellular phones for 10 or more years, increased risk was found for glioma (odds ratio = 2.20).
Problems with the Interphone multinational study...
Risk of a tumour on the same side of the head as reported phone use was raised for use for 10 years or longer (OR = 1.8).
Problems with the Interphone multinational study...
Also digital cellular phones and cordless phones increased the risk to some extent. For acoustic neuroma, analogue phones gave OR = 4.2, increasing to OR = 8.4, with a >15-year latency period, but based on low numbers.
Significantly larger tumours were found among cellular phone users. Overall the OR was not significantly increased but only two cases had used a mobile phone regularly for more than 10 years.
Ten years after the start of mobile phone use when restricting to tumors on the same side of the head as the phone was normally used, the relative risk was 3.9 (1.6-9.5).
Author’s conclusions: our data suggest an increased risk of acoustic neuroma associated with mobile phone use of at least 10 years' duration.
A questionnaire was answered by 1,429 (88%) cases and 1,470 (91%) controls. Use of analog cellular telephones yielded an odds ratio (OR) for brain tumors of 1.31, 95% confidence interval (CI) = 1.04-1.64, increasing for ipsilateral use to OR = 1.65, 95% CI = 1.19-2.30. The authors found the highest risk for the 20-29-yr age group, with OR = 5.91, 95% CI = 0.63-55 for ipsilateral use of analog phones. The highest risks were associated with >5-year latency period in the 20-29-yr age group for analogue phones (OR = 8.17, 95% CI = 0.94-71), and cordless phones (OR = 4.30, 95% CI = 1.22-15).
Indicates 8-fold higher risk associated with analogue mobile phones and 4-fold higher risk associated with cordless phone use.
Found the risk was increased for tumours located in the temporal area on the same side of the brain that was used during phone calls; for analogue cellular telephones the OR was 2.5. With a tumour induction period of >10 years the risk increased further: OR 1.8 (95% CI 1.1-2.9). The highest risk was for acoustic neurinoma (OR 3.5, 95% CI 1.8-6.8) among analogue cellular telephone users.
PubMed Report...
Studies without data on regular and longer term use (more than 10 years):
Takebayashi T et al 2008. Mobile phone use, exposure to radiofrequency electromagnetic field, and brain tumour: a case-control study.
No consistent increase was observed in the overall risk of glioma, meningioma and pituitary adenoma among mobile phone users. A non-significant increase in OR among glioma patients in the heavily exposed group may reflect recall bias.Observation period: December 2000 - November 2004
PubMed Report...
Problems with the Interphone multinational study...
Risk of meningioma among regular users of mobile phones was apparently lower than among never or non-regular users (odds ratio, OR = 0.76, 95% confidence interval, CI 0.65, 0.89). No evidence of increased risk of meningioma in relation to use of mobile phones was found.
Study did not investigate other types of brain tumour.
Problems with the Interphone multinational study...
For regular mobile phone use, the odds ratio was 0.6 for gliomas, 0.8 for meningiomas and 0.5 for acoustic neuromas. Similar results were found with mobile phone use for 6 years or more for gliomas and acoustic neuromas. An exception was meningiomas, where the odds ratio was 1. No association was found between the use of mobile phones and the risk of gliomas, meningiomas or acoustic neuroma. The laterality of mobile phone use did not correlate with the location of the tumours. Limitations (according to author): The observation time was too short to detect long-term effects of mobile phone use
Problems with the Interphone multinational study...
No significant increase of acoustic neuroma risk was observed, with the odds ratio (OR) being 0.73. No cases with more than a 10 year latency period were reported.
Problems with the Interphone multinational study...
Cellular telephone use was not associated with increased risk for brain tumors (SIR = 0.97), acoustic neuromas (SIR = 0.73), salivary gland tumors (SIR = 0.77), eye tumors (SIR = 0.96), or leukemias (SIR = 1.00).
Problems with the Interphone multinational study...
Twelve studies with 2780 cases gave a pooled odds ratio (OR) of 0.98. Little indication was found for increased risks of analogue or digital phone use or temporal or occipital tumors.
A significant excess risk for reported phone use ipsilateral to the tumour (1.24, 1.02 to 1.52) was paralleled by a significant reduction in risk (0.75, 0.61 to 0.93) for contralateral use. Authors’ conclusions: This study suggests that there are no substantially raised risks of glioma in the 10 years after first mobile phone use. Only future studies will be able to address longer latency periods for the development of glioma. The complementary positive and negative risks associated with ipsilateral and contralateral use of the phone in relation to the side of the tumour might be due to recall bias.
Only investigated association within 10 years after first mobile phone use and was unable to evaluate risk after 10 years. Did not distinguish between heavy/regular users and light/sporadic users. The association may have been underestimated because 30% of subjects with tumours were excluded because they had died or were too ill to be interviewed (as compared with only 1% of control group).
Problems with the Interphone multinational study...
For regular mobile phone use, the odds ratio was 0.8 for glioma and 0.7 for meningioma. Similar results were found for more than 10 years' duration of mobile phone use.
Problems with the Interphone multinational study...
Use of cellular telephone was associated with a low risk for high-grade glioma (OR, 0.58)
The ipsilateral use of an analogue cellular phone yielded a significantly increased risk for malignant brain tumours.
A weak association was found between gliomas and analog cellular phones. Users’ duration of use was short, less than one year for digital users.
Analysis of brain and nervous system tumors showed no statistically significant SIRs.
This study has been heavily criticised for flaws in design analysis and follow up such as including non-exposed subjects as exposed and the corporate mobile phone subscribers and cordless phone users in the non-user group. There has been some question as to whether the authors of the study are independent of the mobile phone industry.
As compared with never, or very rarely, having used a cellular telephone, the relative risks associated with a cumulative use of a cellular telephone for more than 100 hours were 0.9 for glioma (95 percent confidence interval, 0.5 to 1.6), 0.7 for meningioma (95 percent confidence interval, 0.3 to 1.7), 1.4 for acoustic neuroma (95 percent confidence interval, 0.6 to 3.5), and 1.0 for all types of tumors combined (95 percent confidence interval, 0.6 to 1.5). There was no evidence that the risks were higher among persons who used cellular telephones for 60 or more minutes per day or regularly for five or more years. Tumors did not occur disproportionately often on the side of head on which the telephone was typically used. Author’s conclusions: these data do not support the hypothesis that the recent use of hand-held cellular telephones causes brain tumors, but they are not sufficient to evaluate the risks among long-term, heavy users and for potentially long induction periods.
Compared with patients who never used handheld cellular telephones, the multivariate odds ratio (OR) associated with regular past or current use was 0.85 (95% confidence interval [CI], 0.6-1.2). The OR for infrequent users (10.1 h/mo) was 0.7 (95% CI, 0.3-1.4). In cases, cerebral tumors occurred more frequently on the same side of the head where cellular telephones had been used (26 vs 15 cases; P = .06), but in the cases with temporal lobe cancer a greater proportion of tumors occurred in the contralateral than ipsilateral side (9 vs 5 cases; P = .33). The OR was less than 1.0 for all histologic categories of brain cancer except for uncommon neuroepitheliomatous cancers (OR, 2.1; 95% CI, 0.9-4.7). Author’s conclusions: Our data suggest that use of handheld cellular telephones is not associated with risk of brain cancer.
Users’ level use was low (median 2.5 hours per month) and duration of use was short (2.8 years) No data were available for long term or heavier users [check]. Funded by Wireless Technology Research Programme, predominantly funded by the cellphone industry.
Non-significantly increased risk was found for tumour in the temporal or occipital lobe on the same side as a cellular phone had been used.
The aim of this study was to investigate trends in the incidence of childhood and adult brain and central nervous system (CNS) tumors in Norway from 1970 through 1999. Age-adjusted incidence rates were reported together with results of loglinear regression and an age-period-cohort model based on the Poisson regression model. In children (<15 years), the proportion of brain and CNS tumors was 28.2% (1,042/3,697) of all new cancer cases compared with 2.8% in adults (13,599/492,237). The overall rate of brain and CNS tumors increased during the study period from 6.49 to 12.02 cases per 100,000 person-years. A trend of leveling off in incidence of most tumor categories during the study period was indicated with a possible continuing increase in the period 1995-1999, especially in the age group 0-4 years and in patients aged 60 years or more. Age and period together provided a satisfactory model in patients being <60 years of age and less completeness of diagnosis was found in males compared with females, possibly due to the distribution in males of more aggressive tumors.
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