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Has the incidence of brain cancer risen in Australia since the introduction of mobile phones 29 years ago?
Abstract
Background:
Mobile phone use in Australia has increased rapidly since its introduction in 1987 with whole population usage being 94% by 2014. We explored the popularly hypothesised association between brain cancer incidence and mobile phone use.
Study methods:
Using national cancer registration data, we examined age and gender specific incidence rates of 19,858 male and 14,222 females diagnosed with brain cancer in Australia between 1982 and 2012, and mobile phone usage data from 1987 to 2012. We modelled expected age specific rates (20-39, 40-59, 60-69, 70-84 years), based on published reports of relative risks (RR) of 1.5 in ever-users of mobile phones, and RR of 2.5 in a proportion of 'heavy users' (19% of all users), assuming a 10-year lag period between use and incidence.
Summary answers:
Age adjusted brain cancer incidence rates (20-84 years, per 100,000) have risen slightly in males (p<0.05) but were stable over 30 years in females (p>0.05) and are higher in males 8.7 (CI=8.1-9.3) than in females, 5.8 (CI=5.3-6.3). Assuming a causal RR of 1.5 and 10-year lag period, the expected incidence rate in males in 2012 would be 11.7 (11-12.4) and in females 7.7 (CI=7.2-8.3), both p<0.01; 1434 cases observed in 2012, vs. 1867 expected. Significant increases in brain cancer incidence were observed (in keeping with modelled rates) only in those aged ≥70 years (both sexes), but the increase in incidence in this age group began from 1982, before the introduction of mobile phones. Modelled expected incidence rates were higher in all age groups in comparison to what was observed. Assuming a causal RR of 2.5 among 'heavy users' gave 2038 expected cases in all age groups.
Limitations:
This is an ecological trends analysis, with no data on individual mobile phone use and outcome.
What this study adds:
The observed stability of brain cancer incidence in Australia between 1982 and 2012 in all age groups except in those over 70 years compared to increasing modelled expected estimates, suggests that the observed increases in brain cancer incidence in the older age group are unlikely to be related to mobile phone use. Rather, we hypothesize that the observed increases in brain cancer incidence in Australia are related to the advent of improved diagnostic procedures when computed tomography and related imaging technologies were introduced in the early 1980s.
... The CEFALO study reported no association between mobile phone use and brain tumors [Aydin et al., 2011], and the findings of the Mobi-Kids study have not yet been reported. Descriptive studies regarding mobile phone subscribers and incidence or associated-mortality of brain tumors by country were performed in New Zealand [Cook et al., 2003;Kim et al., 2015], Switzerland [Röösli et al., 2007], the United Kingdom [de Vocht et al., 2011;de Vocht, 2016;Philips et al., 2018;de Vocht, 2019], four Nordic countries (Denmark, Finland, Norway, and Sweden) [Lönn et al., 2004b;Deltour et al., 2009Deltour et al., , 2012, Australia [Chapman et al., 2016;Karipidis et al., 2018], Sweden [Nilsson et al., 2019], the United States [Little et al., 2012], Israel [Barchana et al., 2012;Keinan-Boker et al., 2018], Japan [Sato et al., 2016], and China [Ding and Wang, 2011]; they reported no association between the two. Therefore, this study aimed to evaluate the time trends in mobile phone subscriptions by network generation and brain cancer incidence by histology and topology in Korea. ...
... The incidence of glioblastoma increased significantly more among those aged ≥55 years than in other age groups [Philips et al., 2018]. In Australia , the incidence of all brain tumors increased, especially among men aged ≥70 years [Chapman et al., 2016]. Among Israeli Jewish individuals (1990)(1991)(1992)(1993)(1994)(1995)(1996)(1997)(1998)(1999)(2000)(2001)(2002)(2003)(2004), the incidence of CNS tumors increased significantly more among those aged ≥65 years than in other age groups [Keinan-Boker et al., 2018]. ...
... The number of mobile phone subscribers was used as a proxy indicator of exposure to RF-EMF of mobile phones in this study; however, this exposure may not have been accurately reflected by the number of mobile phone users. Nevertheless, data on the number of mobile phone users have also been used as exposure data for the RF-EMF of mobile phones in other studies [Cook et al., 2003;Lönn et al., 2004b;Röösli et al., 2007;Deltour et al., 2009;de Vocht et al., 2011;Barchana et al., 2012;Deltour et al., 2012;Little et al., 2012;Kim et al., 2015;Chapman et al., 2016;de Vocht, 2016;Karipidis et al., 2018;Keinan-Boker et al., 2018;Philips et al., 2018;de Vocht, 2019;Nilsson et al., 2019]. Since 2010, the number of mobile phone subscribers has been observed to be more than the Korean population in this study. ...
This study evaluated the time trends in mobile phone subscriber number by mobile network generation (G) and brain cancer incidence by type in Korea. We obtained data from the Information Technology Statistics of Korea (1984–2017) and Korea Central Cancer Registry (1999–2017). The average annual percent change was estimated using Joinpoint regression analysis. We evaluated 29,721 brain cancer cases with an age‐standardized incidence rate (ASR) of 2.89/100,000 persons. The glioma and glioblastoma annual ASR significantly increased in 2.6% and 3.9% of males and 3.0% and 3.8% of females, respectively. The ASR for frontal lobe involvement was the highest. The ASR of gliomas of unspecified grade annually increased by 7.8%; those for unspecified topology and histology decreased. The incidence of glioma, glioblastoma, frontal, temporal, and high‐grade glioma increased among those aged ≥60 years. No association was observed between the mobile phone subscriber number and brain cancer incidence in Korea. Furthermore, long‐term research is warranted because of the latency period of brain cancer.
... Most studies of cancer risk from mobile phones have focused on brain tumours (BT), as the brain is the tissue which most absorbs RF energy emitted by mobile phones when they are held close to the head. Numerous analyses of time trends in brain tumours have been conducted in the last 15 years (Chapman et al., 2016;Choi et al., 2021;Davis et al., 2020;de Vocht, 2019de Vocht, , 2016de Vocht et al., 2011;Deltour et al., 2009;GBD 2016 Brain andOther CNS Cancer Collaborators, 2019;Carlberg, 2017, 2015a;Karipidis et al., 2018;Keinan-Boker et al., 2018;Little et al., 2012;Lonn et al., 2004;Philips et al., 2018;Sato et al., 2016;Voisin et al., 2021;Zada et al., 2012). Globally, the age-standardised incidence rates of brain and CNS cancer tumours has increased by about 17⋅3% between 1990(GBD 2016Brain and Other CNS Cancer Collaborators, 2019, with important geographical variations. ...
... Several studies have reported increases in the incidence of high grade tumours and/or tumours in specific anatomic locations, in particular the frontal and temporal lobe (de Vocht, 2016;Philips et al., 2018;Zada et al., 2012) and postulated these might be related to the use of mobile phones in the population. Further analyses and comparisons across countries and age groups suggest these may reflect improved data collection practices in surveillance systems, in particular at older ages, making any inference about possible effects of mobile phones difficult (Chapman et al., 2016;Davis et al., 2020;de Vocht, 2019;Hardell and Carlberg, 2017). Studies of time trends in young people are likely to be less prone to diagnostic uncertainties, but few studies are available. ...
... Most studies of cancer risk from mobile phones have focused on brain tumours (BT), as the brain is the tissue which most absorbs RF energy emitted by mobile phones when they are held close to the head. Numerous analyses of time trends in brain tumours have been conducted in the last 15 years (Chapman et al., 2016;Choi et al., 2021;Davis et al., 2020;de Vocht, 2019de Vocht, , 2016de Vocht et al., 2011;Deltour et al., 2009;GBD 2016 Brain andOther CNS Cancer Collaborators, 2019;Carlberg, 2017, 2015a;Karipidis et al., 2018;Keinan-Boker et al., 2018;Little et al., 2012;Lonn et al., 2004;Philips et al., 2018;Sato et al., 2016;Voisin et al., 2021;Zada et al., 2012). Globally, the age-standardised incidence rates of brain and CNS cancer tumours has increased by about 17⋅3% between 1990(GBD 2016Brain and Other CNS Cancer Collaborators, 2019, with important geographical variations. ...
... Several studies have reported increases in the incidence of high grade tumours and/or tumours in specific anatomic locations, in particular the frontal and temporal lobe (de Vocht, 2016;Philips et al., 2018;Zada et al., 2012) and postulated these might be related to the use of mobile phones in the population. Further analyses and comparisons across countries and age groups suggest these may reflect improved data collection practices in surveillance systems, in particular at older ages, making any inference about possible effects of mobile phones difficult (Chapman et al., 2016;Davis et al., 2020;de Vocht, 2019;Hardell and Carlberg, 2017). Studies of time trends in young people are likely to be less prone to diagnostic uncertainties, but few studies are available. ...
In recent decades, the possibility that use of mobile communicating devices, particularly wireless (mobile and cordless) phones, may increase brain tumour risk, has been a concern, particularly given the considerable increase in their use by young people. MOBI-Kids, a 14-country (Australia, Austria, Canada, France, Germany, Greece, India, Israel, Italy, Japan, Korea, the Netherlands, New Zealand, Spain) case-control study, was conducted to evaluate whether wireless phone use (and particularly resulting exposure to radiofrequency (RF) and extremely low frequency (ELF) electromagnetic fields (EMF)) increases risk of brain tumours in young people. Between 2010 and 2015, the study recruited 899 people with brain tumours aged 10 to 24 years old and 1,910 controls (operated for appendicitis) matched to the cases on date of diagnosis, study region and age. Participation rates were 72% for cases and 54% for controls.
The mean ages of cases and controls were 16.5 and 16.6 years, respectively; 57% were males. The vast majority of study participants were wireless phones users, even in the youngest age group, and the study included substantial numbers of long-term (over 10 years) users: 22% overall, 51% in the 20–24-year-olds.
Most tumours were of the neuroepithelial type (NBT; n = 671), mainly glioma. The odds ratios (OR) of NBT appeared to decrease with increasing time since start of use of wireless phones, cumulative number of calls and cumulative call time, particularly in the 15–19 years old age group. A decreasing trend in ORs was also observed with increasing estimated cumulative RF specific energy and ELF induced current density at the location of the tumour.
Further analyses suggest that the large number of ORs below 1 in this study is unlikely to represent an unknown causal preventive effect of mobile phone exposure: they can be at least partially explained by differential recall by proxies and prodromal symptoms affecting phone use before diagnosis of the cases. We cannot rule out, however, residual confounding from sources we did not measure.
Overall, our study provides no evidence of a causal association between wireless phone use and brain tumours in young people. However, the sources of bias summarised above prevent us from ruling out a small increased risk.
... In recent years, we've seen apocalyptic pre¬ dictions made about mobile phones doing to brain cancer what smoking did to lung cancer. Unfortunately for these forecasters, the incidence of brain cancer has flat-lined for over thirty years while mobile phone use has been almost universal for about 15 years (Chapman et al. 2016) In 2006, two authors writing in Electro¬ magnetic Biology and Medicine (Hallberg and Oberfeld 2006) • Experimental subjects randomised to be exposed or not exposed to negative news footage about wind farm harms and then That's about the distance from downtown Sydney to the northern suburb of Chatswood. Indeed, she believes these vibrations are "sufficient to knock them off their feet or bring some men to their knees when out working in their paddock". ...
... In different studies, it has been reported that mobile phone use causes deterioration in physiological functions such as; impair memory (5), increase parasympathetic nerve activity (6), worsen thyroid functions (7), increase oxidative stress (8), axon and myelin damage (9), weaken the immune system (10), increased permeability of blood-brain barrier (11), oxidative stress in peripheral nerves and morphological changes (12). However, some studies suggest that RF energy does not cause any harmful effects on biological systems (13)(14)(15). Vision is a very important sense for humans and animals. About 70-80% of environmental information is acquired through vision. ...
... A similar study by Chapman et al. examined overall brain cancer incidence trends and phone use in Australia (18). The study included 34,080 diagnosed cases of brain cancer from 1982 to 2012. ...
... "Further analyses and comparisons across countries and age groups suggest these may reflect improved data collection practices in surveillance systems, in particular at older ages, making any inference about possible effects of mobile phones difficult." That statement in MOBI-Kids was exemplified by, for example, an Australian study on brain cancer between 1982 and 2012, and mobile phone usage data from 1987 to 2012 [19]. However, that study has been criticized to be biased [20]: "There are some serious errors in Chapman et al. [1] on mobile phone use and brain cancer that warrant the paper's retraction. ...
The MOBI-Kids case-control study on wireless phone use and brain tumor risk in childhood and adolescence included the age group 10–24 years diagnosed between 2010 and 2015. Overall no increased risk was found although for brain tumors in the temporal region an increased risk was found in the age groups 10–14 and 20–24 years. Most odds ratios (ORs) in MOBI-Kids were <1.0, some statistically significant, suggestive of a preventive effect from RF radiation; however, this is in contrast to current knowledge about radiofrequency (RF) carcinogenesis. The MOBI-Kids results are not biologically plausible and indicate that the study was flawed due to methodological problems. For example, not all brain tumor cases were included since central localization was excluded. Instead, all brain tumor cases should have been included regardless of histopathology and anatomical localization. Only surgical controls with appendicitis were used instead of population-based controls from the same geographical area as for the cases. In fact, increased incidence of appendicitis has been postulated to be associated with RF radiation which makes selection of control group in MOBI-Kids questionable. Start of wireless phone use up to 10 years before diagnosis was in some analyses included in the unexposed group. Thus, any important results demonstrating late carcinogenesis, a promoter effect, have been omitted from analysis and may underestimate true risks. Linear trend was in some analyses statistically significant in the calculation of RF-specific energy and extremely low frequency (ELF)-induced current in the center of gravity of the tumor. Additional case-case analysis should have been performed. The data from this study should be reanalyzed using unconditional regression analysis adjusted for potential confounding factors to increase statistical power. Then all responding cases and controls could be included in the analyses. In sum, we believe the results as reported in this paper seem uninterpretable and should be dismissed.
... In a series of case-control studies in Sweden, consistently strong positive associations for ever cellular telephone use were observed, even within a short time after first use (27,28). If true, this would by now have led to a massive epidemic of brain tumors that-fortunately-has not happened (29)(30)(31). Hence, some major underlying bias in either the recruitment of study participants or in assessing exposure is the likely explanation for their findings. ...
Background:
The ongoing debate of whether use of cellular telephones increases the risk of developing a brain tumor was recently fueled by the launch of the fifth generation of wireless technologies. Here, we update follow-up of a large-scale prospective study on the association between cellular telephone use and brain tumors.
Methods:
During 1996-2001, 1.3 million women born in 1935-1950 were recruited into the study. Questions on cellular telephone use were first asked in median year 2001 and again in median year 2011. All study participants were followed via record linkage to National Health Services databases on deaths and cancer registrations (including nonmalignant brain tumors).
Results:
During 14 years follow-up of 776 156 women who completed the 2001 questionnaire, a total of 3268 incident brain tumors were registered. Adjusted relative risks for ever vs never cellular telephone use were 0.97 (95% confidence interval = 0.90 to 1.04) for all brain tumors, 0.89 (95% confidence interval = 0.80 to 0.99) for glioma, and not statistically significantly different to 1.0 for meningioma, pituitary tumors, and acoustic neuroma. Compared with never-users, no statistically significant associations were found, overall or by tumor subtype, for daily cellular telephone use or for having used cellular telephones for at least 10 years. Taking use in 2011 as baseline, there were no statistically significant associations with talking for at least 20 minutes per week or with at least 10 years use. For gliomas occurring in the temporal and parietal lobes, the parts of the brain most likely to be exposed to radiofrequency electromagnetic fields from cellular telephones, relative risks were slightly below 1.0.
Conclusion:
Our findings support the accumulating evidence that cellular telephone use under usual conditions does not increase brain tumor incidence.
Background
The World Health Organization (WHO) has an ongoing project to assess potential health effects of exposure to radiofrequency electromagnetic fields (RF-EMF) in the general and working population. Here we present the protocol for a systematic review of the scientific literature on cancer hazards from exposure to RF-EMF in humans, commissioned by the WHO as part of that project.
Objective
To assess the quality and strength of the evidence provided by human observational studies for a causal association between exposure to RF-EMF and risk of neoplastic diseases.
Eligibility criteria
We will include cohort and case-control studies investigating neoplasia risks in relation to three types of exposure to RF-EMF: near-field, head-localized, exposure from wireless phone use (SR-A); far-field, whole body, environmental exposure from fixed-site transmitters (SR-B); near/far-field occupational exposures from use of handheld transceivers or RF-emitting equipment in the workplace (SR-C). While no restriction on tumour type will be applied, we will focus on selected neoplasms of the central nervous system (brain, meninges, pituitary gland, acoustic nerve) and salivary gland tumours (SR-A); brain tumours and leukaemias (SR-B, SR-C).
Information sources
Eligible studies will be identified through Medline, Embase, and EMF-Portal.
Risk-of-bias assessment
We will use a tailored version of the OHAT's tool to evaluate the study's internal validity.
Data synthesis
We will consider separately studies on different tumours, neoplasm-specific risks from different exposure sources, and a given exposure-outcome pair in adults and children. When a quantitative synthesis of findings can be envisaged, the main aims of the meta-analysis will be to assess the strength of association and the shape of the exposure–response relationship; to quantify the degree of heterogeneity across studies; and explore the sources of inconsistency (if any). When a meta-analysis is judged inappropriate, we will perform a narrative synthesis, complemented by a structured tabulation of results and appropriate visual displays.
Evidence assessment
Confidence in evidence will be assessed in line with the GRADE approach.
Funding
This project is supported by the World Health Organization. Co-financing was provided by the New Zealand Ministry of Health; the Istituto Superiore di Sanità in its capacity as a WHO Collaborating Centre for Radiation and Health; ARPANSA as a WHO Collaborating Centre for Radiation Protection.
Registration
PROSPERO CRD42021236798.
Quickly changing technologies and intensive uses of radiofrequency electromagnetic field (RF-EMF)‑emitting phones pose a challenge to public health. Mobile phone users and uses and exposures to other wireless transmitting devices (WTDs) have increased in the past few years. We consider that CERENAT, a French national study, provides an important addition to the literature evaluating the use of mobile phones and risk of brain tumors. The CERENAT finding of increased risk of glioma is consistent with studies that evaluated use of mobile phones for a decade or longer and corroborate those that have shown a risk of meningioma from mobile phone use. In CERENAT, exposure to RF‑EMF from digitally enhanced cordless telephones (DECTs), used by over half the population of France during the period of this study, was not evaluated. If exposures to DECT phones could have been taken into account, the risks of glioma from mobile phone use in CERENAT are likely to be higher than published. We conclude that radiofrequency fields should be classified as a Group 2A ̔probable̓ human carcinogen under the criteria used by the International Agency for Research on Cancer (Lyon, France). Additional data should be gathered on exposures to mobile and cordless phones, other WTDs, mobile phone base stations and Wi‑Fi routers to evaluate their impact on public health. We advise that the as low as reasonable achievable (ALARA) principle be adopted for uses of this technology, while a major cross‑disciplinary effort is generated to train researchers in bioelectromagnetics and provide monitoring of potential health impacts of RF‑EMF.
Objective: Case-control studies have linked mobile phone use to an increased risk of glioma in the most exposed brain areas, the temporal and parietal lobes, although inconsistently. We examined time trends in the incidence rates of brain malignancies in New Zealand from 1995 to 2010. Methods: Data from the New Zealand Cancer Registry was used to calculate incidence rates of primary brain cancer, by age, gender, morphology and anatomical site. Log-linear regression analysis was used to assess trends in the annual incidence of primary brain cancer; annual percentage changes and their 95% confidence intervals were estimated. Results: No consistent increases in all primary brain cancer, glioma, or temporal or parietal lobe glioma were seen. At ages 10-69, the incidence of all brain cancers declined significantly. Incidence of glioma increased at ages over 70. Conclusion: In New Zealand, there has been no consistent increase in incidence rates of primary brain cancers. An increase in glioma at ages over 70 is likely to be due to improvements in diagnosis. As with any such studies, a small effect, or one with a latent period of more than 10 to 15 years, cannot be excluded.
© 2015 Public Health Association of Australia.
Background
Since 1997, the NSW Population Health Survey (NSWPHS) had selected the sample using random digit dialing of landline telephone numbers. When the survey began coverage of the population by landline phone frames was high (96%). As landline coverage in Australia has declined and continues to do so, in 2012, a sample of mobile telephone numbers was added to the survey using an overlapping dual-frame design. Details of the methodology are published elsewhere. This paper discusses the impacts of the sampling frame change on the time series, and provides possible approaches to handling these impacts.
Methods
Prevalence estimates were calculated for type of phone-use, and a range of health indicators. Prevalence ratios (PR) for each of the health indicators were also calculated using Poisson regression analysis with robust variance estimation by type of phone-use. Health estimates for 2012 were compared to 2011. The full time series was examined for selected health indicators.
Results
It was estimated from the 2012 NSWPHS that 20.0% of the NSW population were mobile-only phone users. Looking at the full time series for overweight or obese and current smoking if the NSWPHS had continued to be undertaken only using a landline frame, overweight or obese would have been shown to continue to increase and current smoking would have been shown to continue to decrease. However, with the introduction of the overlapping dual-frame design in 2012, overweight or obese increased until 2011 and then decreased in 2012, and current smoking decreased until 2011, and then increased in 2012. Our examination of these time series showed that the changes were a consequence of the sampling frame change and were not real changes. Both the backcasting method and the minimal coverage method could adequately adjust for the design change and allow for the continuation of the time series.
Conclusions
The inclusion of the mobile telephone numbers, through an overlapping dual-frame design, did impact on the time series for some of the health indicators collected through the NSWPHS, but only in that it corrected the estimates that were being calculated from a sample frame that was progressively covering less of the population.
To assess the cancer risk in children and adolescents following exposure to low dose ionising radiation from diagnostic computed tomography (CT) scans. DESIGN : Population based, cohort, data linkage study in Australia. COHORT MEMBERS: 10.9 million people identified from Australian Medicare records, aged 0-19 years on 1 January 1985 or born between 1 January 1985 and 31 December 2005; all exposures to CT scans funded by Medicare during 1985-2005 were identified for this cohort. Cancers diagnosed in cohort members up to 31 December 2007 were obtained through linkage to national cancer records.
Cancer incidence rates in individuals exposed to a CT scan more than one year before any cancer diagnosis, compared with cancer incidence rates in unexposed individuals.
60 674 cancers were recorded, including 3150 in 680 211 people exposed to a CT scan at least one year before any cancer diagnosis. The mean duration of follow-up after exposure was 9.5 years. Overall cancer incidence was 24% greater for exposed than for unexposed people, after accounting for age, sex, and year of birth (incidence rate ratio (IRR) 1.24 (95% confidence interval 1.20 to 1.29); P<0.001). We saw a dose-response relation, and the IRR increased by 0.16 (0.13 to 0.19) for each additional CT scan. The IRR was greater after exposure at younger ages (P<0.001 for trend). At 1-4, 5-9, 10-14, and 15 or more years since first exposure, IRRs were 1.35 (1.25 to 1.45), 1.25 (1.17 to 1.34), 1.14 (1.06 to 1.22), and 1.24 (1.14 to 1.34), respectively. The IRR increased significantly for many types of solid cancer (digestive organs, melanoma, soft tissue, female genital, urinary tract, brain, and thyroid); leukaemia, myelodysplasia, and some other lymphoid cancers. There was an excess of 608 cancers in people exposed to CT scans (147 brain, 356 other solid, 48 leukaemia or myelodysplasia, and 57 other lymphoid). The absolute excess incidence rate for all cancers combined was 9.38 per 100 000 person years at risk, as of 31 December 2007. The average effective radiation dose per scan was estimated as 4.5 mSv.
The increased incidence of cancer after CT scan exposure in this cohort was mostly due to irradiation. Because the cancer excess was still continuing at the end of follow-up, the eventual lifetime risk from CT scans cannot yet be determined. Radiation doses from contemporary CT scans are likely to be lower than those in 1985-2005, but some increase in cancer risk is still likely from current scans. Future CT scans should be limited to situations where there is a definite clinical indication, with every scan optimised to provide a diagnostic CT image at the lowest possible radiation dose.
Objective To assess the cancer risk in children and adolescents following exposure to low dose ionising radiation from diagnostic computed tomography (CT) scans. Design Population based, cohort, data linkage study in Australia. Cohort members 10.9 million people identified from Australian Medicare records, aged 0-19 years on 1 January 1985 or born between 1 January 1985 and 31 December 2005; all exposures to CT scans funded by Medicare during 1985-2005 were identified for this cohort. Cancers diagnosed in cohort members up to 31 December 2007 were obtained through linkage to national cancer records. Main outcome Cancer incidence rates in individuals exposed to a CT scan more than one year before any cancer diagnosis, compared with cancer incidence rates in unexposed individuals. Results 60 674 cancers were recorded, including 3150 in 680 211 people exposed to a CT scan at least one year before any cancer diagnosis. The mean duration of follow-up after exposure was 9.5 years. Overall cancer incidence was 24% greater for exposed than for unexposed people, after accounting for age, sex, and year of birth (incidence rate ratio (IRR) 1.24 (95% confidence interval 1.20 to 1.29); P<0.001). We saw a dose-response relation, and the IRR increased by 0.16 (0.13 to 0.19) for each additional CT scan. The IRR was greater after exposure at younger ages (P<0.001 for trend). At 1-4, 5-9, 10-14, and 15 or more years since first exposure, IRRs were 1.35 (1.25 to 1.45), 1.25 (1.17 to 1.34), 1.14 (1.06 to 1.22), and 1.24 (1.14 to 1.34), respectively. The IRR increased significantly for many types of solid cancer (digestive organs, melanoma, soft tissue, female genital, urinary tract, brain, and thyroid); leukaemia, myelodysplasia, and some other lymphoid cancers. There was an excess of 608 cancers in people exposed to CT scans (147 brain, 356 other solid, 48 leukaemia or myelodysplasia, and 57 other lymphoid). The absolute excess incidence rate for all cancers combined was 9.38 per 100 000 person years at risk, as of 31 December 2007. The average effective radiation dose per scan was estimated as 4.5 mSv. Conclusions The increased incidence of cancer after CT scan exposure in this cohort was mostly due to irradiation. Because the cancer excess was still continuing at the end of follow-up, the eventual lifetime risk from CT scans cannot yet be determined. Radiation doses from contemporary CT scans are likely to be lower than those in 1985-2005, but some increase in cancer risk is still likely from current scans. Future CT scans should be limited to situations where there is a definite clinical indication, with every scan optimised to provide a diagnostic CT image at the lowest possible radiation dose.
Background:
Results from some retrospective studies suggest a possible increased risk of glioma and acoustic neuroma in users of mobile phones.
Methods:
The relation between mobile phone use and incidence of intracranial central nervous system (CNS) tumours and other cancers was examined in 791,710 middle-aged women in a UK prospective cohort, the Million Women Study. Cox regression models were used to estimate adjusted relative risks (RRs) and 95% confidence intervals (CIs). Women reported mobile phone use in 1999 to 2005 and again in 2009.
Results:
During 7 years' follow-up, 51,680 incident invasive cancers and 1,261 incident intracranial CNS tumours occurred. Risk among ever vs never users of mobile phones was not increased for all intracranial CNS tumours (RR = 1.01, 95% CI = 0.90-1.14, P = 0.82), for specified CNS tumour types nor for cancer at 18 other specified sites. For long-term users compared with never users, there was no appreciable association for glioma (10+ years: RR = 0.78, 95% CI = 0.55-1.10, P = 0.16) or meningioma (10+ years: RR = 1.10, 95% CI = 0.66-1.84, P = 0.71). For acoustic neuroma, there was an increase in risk with long term use vs never use (10+ years: RR = 2.46, 95% CI = 1.07-5.64, P = 0.03), the risk increasing with duration of use (trend among users, P = 0.03).
Conclusions:
In this large prospective study, mobile phone use was not associated with increased incidence of glioma, meningioma or non-CNS cancers.
Background The rapid increase in mobile telephone use has generated concern about possible health risks related to radiofrequency electromagnetic fields from this technology.
Methods An interview-based case–control study with 2708 glioma and 2409 meningioma cases and matched controls was conducted in 13 countries using a common protocol.
Results A reduced odds ratio (OR) related to ever having been a regular mobile phone user was seen for glioma [OR 0.81; 95% confidence interval (CI) 0.70–0.94] and meningioma (OR 0.79; 95% CI 0.68–0.91), possibly reflecting participation bias or other methodological limitations. No elevated OR was observed ≥10 years after first phone use (glioma: OR 0.98; 95% CI 0.76–1.26; meningioma: OR 0.83; 95% CI 0.61–1.14). ORs were <1.0 for all deciles of lifetime number of phone calls and nine deciles of cumulative call time. In the 10th decile of recalled cumulative call time, ≥1640 h, the OR was 1.40 (95% CI 1.03–1.89) for glioma, and 1.15 (95% CI 0.81–1.62) for meningioma; but there are implausible values of reported use in this group. ORs for glioma tended to be greater in the temporal lobe than in other lobes of the brain, but the CIs around the lobe-specific estimates were wide. ORs for glioma tended to be greater in subjects who reported usual phone use on the same side of the head as their tumour than on the opposite side.
Conclusions Overall, no increase in risk of glioma or meningioma was observed with use of mobile phones. There were suggestions of an increased risk of glioma at the highest exposure levels, but biases and error prevent a causal interpretation. The possible effects of long-term heavy use of mobile phones require further investigation.
The incidence of primary brain tumors by subtype is currently unknown in Australia. We report an analysis of incidence by tumor subtype in a retrospective multicenter study in the state of New South Wales (NSW) and the Australian Capital Territory (ACT), with a combined population of >7 million with >97% retention rate for medical care.
Data from histologically confirmed primary brain tumors diagnosed from January 2000 through December 2008 were weighted for patient outflow and data completeness, and age standardized and analyzed using joinpoint analysis.
A significant increasing incidence in glioblastoma multiforme (GBM) was observed in the study period (annual percentage change [APC], 2.5; 95% confidence interval [CI], 0.4-4.6, n = 2275), particularly after 2006. In GBM patients in the ≥65-year group, a significantly increasing incidence for men and women combined (APC, 3.0; 95% CI, 0.5-5.6) and men only (APC, 2.9; 95% CI, 0.1-5.8) was seen. Rising trends in incidence were also seen for meningioma in the total male population (APC, 5.3; 95% CI, 2.6-8.1, n = 515) and males aged 20-64 years (APC, 6.3; 95% CI, 3.8-8.8). Significantly decreasing incidence trends were observed for Schwannoma for the total study population (APC, -3.5; 95% CI, -7.2 to -0.2, n = 492), significant in women (APC, -5.3; 95% CI, -9.9 to -0.5) but not men.
This collection is the most contemporary data on primary brain tumor incidence in Australia. Our registries may observe an increase in malignant tumors in the next few years that they are not detecting now due to late ascertainment. We recommend a direct, uniform, and centralized approach to monitoring primary brain tumor incidence by subtype, including the introduction of nonmalignant data collection.