Validation of mobile phone use recall in the multinational MOBI-kids study.

Potential differential and non-differential recall error in mobile phone use (MPU) in the multinational MOBI-Kids case-control study were evaluated. We compared self-reported MPU with network operator billing record data up to 3 months, 1 year, and 2 years before the interview date from 702 subjects aged between 10 and 24 years in eight countries. Spearman rank correlations, Kappa coefficients and geometric mean ratios (GMRs) were used. No material differences in MPU recall estimates between cases and controls were observed. The Spearman rank correlation coefficients between self-reported and recorded MPU in the most recent 3 months were 0.57 and 0.59 for call number and for call duration, respectively. The number of calls was on average underestimated by the participants (GMR = 0.69), while the duration of calls was overestimated (GMR = 1.59). Country, years since start of using a mobile phone, age at time of interview, and sex did not appear to influence recall accuracy for either call number or call duration. A trend in recall error was seen with level of self-reported MPU, with underestimation of use at lower levels and overestimation of use at higher levels for both number and duration of calls. Although both systematic and random errors in self-reported MPU among participants were observed, there was no evidence of differential recall error between cases and controls. Nonetheless, these sources of exposure measurement error warrant consideration in interpretation of the MOBI-Kids case-control study results on the association between children's use of mobile phones and potential brain cancer risk.

Radiation exposure and leukaemia risk among cohorts of persons exposed to low and moderate doses of external ionising radiation in childhood.

BACKGROUND: Many high-dose groups demonstrate increased leukaemia risks, with risk greatest following childhood exposure; risks at low/moderate doses are less clear. METHODS: We conducted a pooled analysis of the major radiation-associated leukaemias (acute myeloid leukaemia (AML) with/without the inclusion of myelodysplastic syndrome (MDS), chronic myeloid leukaemia (CML), acute lymphoblastic leukaemia (ALL)) in ten childhood-exposed groups, including Japanese atomic bomb survivors, four therapeutically irradiated and five diagnostically exposed cohorts, a mixture of incidence and mortality data. Relative/absolute risk Poisson regression models were fitted. RESULTS: Of 365 cases/deaths of leukaemias excluding chronic lymphocytic leukaemia, there were 272 AML/CML/ALL among 310,905 persons (7,641,362 person-years), with mean active bone marrow (ABM) dose of 0.11 Gy (range 0-5.95). We estimated significant (P < 0.005) linear excess relative risks/Gy (ERR/Gy) for: AML (n = 140) = 1.48 (95% CI 0.59-2.85), CML (n = 61) = 1.77 (95% CI 0.38-4.50), and ALL (n = 71) = 6.65 (95% CI 2.79-14.83). There is upward curvature in the dose response for ALL and AML over the full dose range, although at lower doses (<0.5 Gy) curvature for ALL is downwards. DISCUSSION: We found increased ERR/Gy for all major types of radiation-associated leukaemia after childhood exposure to ABM doses that were predominantly (for 99%) <1 Gy, and consistent with our prior analysis focusing on <100 mGy.

Association of allergic diseases and epilepsy with risk of glioma, meningioma and acoustic neuroma: results from the INTERPHONE international case-control study.

We investigated the association of allergic diseases and epilepsy with risk of brain tumours, in Interphone, a 13-country case-control study. Data were obtained from 2693 glioma cases, 2396 meningioma cases, and 1102 acoustic neuroma cases and their 6321 controls. Conditional logistic regression models were used to estimate pooled odds ratios (ORs) and their respective 95% confidence intervals (CIs), adjusted for education and time at interview. Reduced ORs were observed for glioma in relation to physician-diagnosed asthma (OR = 0.73; CI 0.58-0.92), hay fever (OR 0.72; CI 0.61-0.86), and eczema (OR 0.78, CI 0.64-0.94), but not for meningioma or acoustic neuroma. Previous diagnosis of epilepsy was associated with an increased OR for glioma (2.94; CI 1.87-4.63) and for meningioma (2.12; CI 1.27-3.56), but not for acoustic neuroma. This large-scale case-control study adds to the growing evidence that people with allergies have a lower risk of developing glioma, but not meningioma or acoustic neuroma. It also supports clinical observations of epilepsy prior to the diagnosis of glioma and meningioma.

Childhood Exposure to Low to Moderate Doses of Ionizing Radiation and the Risk of Vascular Diseases.

In the Tinea Capitis Study (Israel, 1966-2011), we assessed the association between childhood exposure to low to moderate doses of ionizing radiation (IR) to the head and neck and the development of vascular diseases (ischemic heart disease, carotid artery stenosis, and stroke) in adulthood. The study included 17,734 individuals from the Tinea Capitis cohort (7,408 irradiated in childhood and 10,326 nonirradiated), insured by Israel's largest health provider. Individual dosimetry was estimated based on measurements made on a head phantom and original treatment records. The mean doses were 1.5, 0.09, 0.78, and 0.017 Gy to brain, thyroid, salivary gland, and breast, respectively. Data on vascular diseases was abstracted from computerized medical records. Using Poisson regressions, we examined the association of radiation with morbidity. Any vascular disease was reported for 2,221 individuals. Adjusted for age, sex, socioeconomic status, smoking, hypertension, and diabetes, exposure to IR increased the risk of developing any vascular diseases (relative risk (RR) = 1.19, 95% confidence interval (CI): 1.09, 1.29), stroke (RR = 1.35, 1.20, 1.53), carotid artery stenosis (RR = 1.32, 1.06, 1.64), and ischemic heart disease (RR = 1.12, 1.01, 1.26). The risk of developing vascular diseases was positively associated with dose and inversely associated with age at exposure. In conclusion, the results indicate that early exposure to low to moderate doses of IR increases the risk of cerebro- and cardiovascular impairments.

Breast cancer survivors: physical and mental quality of life 10 years following diagnosis, a case-control study.

PURPOSE: Improvements in diagnosis and treatment of Breast Cancer (BC) have resulted in an increase in the life expectancy of survivors and in the importance of quality of life in BC survivorship care. The current study aimed to assess the Health-Related Quality Of Life (HRQOL) of BC survivors and to investigate the association of comorbidities with HRQOL compared to a group of women with no history of cancer. METHODS: Women were residents of the central district in Israel, the case group included 250 women diagnosed with BC between 1999 and 2003, with no prior cancer history and no evidence of disease after 8-12 years. The comparison group included 250 women with no cancer history, individually matched to cases by age and area of residence. Data were collected through in-person interviews, and HRQOL was assessed using the Short Form-36 (SF-36) questionnaire. Regression analyses were performed evaluating the influence of demographic, socioeconomic, lifestyle characteristics and comorbidities on physical and mental HRQOL. RESULTS: The physical and mental summary scores means, were 48.5 ± 11.1 and 49.2 ± 10.8 compared to 51.5 ± 10.2 and 50.9 ± 10.6, in BC survivors and the comparison group, respectively (p = 0.002 and p = 0.097). BC survivors and controls did not differ in number and type of comorbidities and for both groups a negative association was seen with HRQOL. Controlling for age, income, number of comorbidities, BMI and physical activity, BC survivor had decreased physical (b = -2.49, p = 0.001) and mental summary scores (b = -1.27, p = 0.18). CONCLUSION: HRQOL of BC survivors should gain more attention in the area of cancer care, especially when comorbidities are present.

Nationwide seroprevalence of antibodies against SARS-CoV-2 in Israel.

The first local spread of COVID-19 in Israel was detected in March 2020. Due to the diversity in clinical presentations of COVID-19, diagnosis by RT-PCR alone might miss patients with mild or no symptoms. Serology testing may better evaluate the actual magnitude of the spread of infection in the population. This is the first nationwide seroprevalence study conducted in Israel. It is one of the most widespread to be conducted thus far, and the largest per-country population size. The survey was conducted between June 28 and September 14, 2020 and included 54,357 patients who arrived at the Health Maintenance Organizations to undergo a blood test for any reason. A patient was considered seropositive after two consecutive positive results with two different kits (Abbott and DiaSorin).The overall seroprevalence was 3.8% (95%CI 3.7-4.0), males higher than females [4.9% (95%CI 4.6-5.2) vs. 3.1% (95%CI 2.9-3.3) respectively]. Adolescents had the highest prevalence [7.8% (95%CI 7.0-8.6)] compared to other age groups. Participants who had undergone RT-PCR testing had a tenfold higher risk to be seropositive. The prevalence-to-incidence ratio was 4.5-15.7. Serology testing is an important complimentary tool for assessing the actual magnitude of infection and thus essential for implementing policy measures to control the pandemic. A positive serology test result was recently accepted in Israel as being sufficient to define recovery, with possible far-reaching consequences, such as the deploying of employees to ensure the maintenance of a functional economy.

Glioma risk associated with extent of estimated European genetic ancestry in African Americans and Hispanics.

Glioma incidence is highest in non-Hispanic Whites, and to date, glioma genome-wide association studies (GWAS) to date have only included European ancestry (EA) populations. African Americans and Hispanics in the US have varying proportions of EA, African (AA) and Native American ancestries (NAA). It is unknown if identified GWAS loci or increased EA is associated with increased glioma risk. We assessed whether EA was associated with glioma in African Americans and Hispanics. Data were obtained for 832 cases and 675 controls from the Glioma International Case-Control Study and GliomaSE Case-Control Study previously estimated to have <80% EA, or self-identify as non-White. We estimated global and local ancestry using fastStructure and RFMix, respectively, using 1,000 genomes project reference populations. Within groups with ≥40% AA (AFR≥0.4 ), and ≥15% NAA (AMR≥0.15 ), genome-wide association between local EA and glioma was evaluated using logistic regression conditioned on global EA for all gliomas. We identified two regions (7q21.11, p = 6.36 × 10-4 ; 11p11.12, p = 7.0 × 10-4 ) associated with increased EA, and one associated with decreased EA (20p12.13, p = 0.0026) in AFR≥0.4 . In addition, we identified a peak at rs1620291 (p = 4.36 × 10-6 ) in 7q21.3. Among AMR≥0.15 , we found an association between increased EA in one region (12q24.21, p = 8.38 × 10-4 ), and decreased EA in two regions (8q24.21, p = 0. 0010; 20q13.33, p = 6.36 × 10-4 ). No other significant associations were identified. This analysis identified an association between glioma and two regions previously identified in EA populations (8q24.21, 20q13.33) and four novel regions (7q21.11, 11p11.12, 12q24.21 and 20p12.13). The identifications of novel association with EA suggest regions to target for future genetic association studies.

Clinical presentation of young people (10-24 years old) with brain tumors: results from the international MOBI-Kids study.

INTRODUCTION: We used data from MOBI-Kids, a 14-country international collaborative case-control study of brain tumors (BTs), to study clinical characteristics of the tumors in older children (10 years or older), adolescents and young adults (up to the age of 24). METHODS: Information from clinical records was obtained for 899 BT cases, including signs and symptoms, symptom onset, diagnosis date, tumor type and location. RESULTS: Overall, 64% of all tumors were low-grade, 76% were neuroepithelial tumors and 62% gliomas. There were more males than females among neuroepithelial and embryonal tumor cases, but more females with meningeal tumors. The most frequent locations were cerebellum (22%) and frontal (16%) lobe. The most frequent symptom was headaches (60%), overall, as well as for gliomas, embryonal and 'non-neuroepithelial' tumors; it was convulsions/seizures for neuroepithelial tumors other than glioma, and visual signs and symptoms for meningiomas. A cluster analysis showed that headaches and nausea/vomiting was the only combination of symptoms that exceeded a cutoff of 50%, with a joint occurrence of 67%. Overall, the median time from first symptom to diagnosis was 1.42 months (IQR 0.53-4.80); it exceeded 1 year in 12% of cases, though no particular symptom was associated with exceptionally long or short delays. CONCLUSIONS: This is the largest clinical epidemiology study of BT in young people conducted so far. Many signs and symptoms were identified, dominated by headaches and nausea/vomiting. Diagnosis was generally rapid but in 12% diagnostic delay exceeded 1 year with none of the symptoms been associated with a distinctly long time until diagnosis.

Nonparticipation Selection Bias in the MOBI-Kids Study.

BACKGROUND: MOBI-Kids is a 14-country case-control study designed to investigate the potential effects of electromagnetic field exposure from mobile telecommunications devices on brain tumor risk in children and young adults conducted from 2010 to 2016. This work describes differences in cellular telephone use and personal characteristics among interviewed participants and refusers responding to a brief nonrespondent questionnaire. It also assesses the potential impact of nonparticipation selection bias on study findings. METHODS: We compared nonrespondent questionnaires completed by 77 cases and 498 control refusers with responses from 683 interviewed cases and 1501 controls (suspected appendicitis patients) in six countries (France, Germany, Israel, Italy, Japan, and Spain). We derived selection bias factors and estimated inverse probability of selection weights for use in analysis of MOBI-Kids data. RESULTS: The prevalence of ever-regular use was somewhat higher among interviewed participants than nonrespondent questionnaire respondents 10-14 years of age (68% vs. 62% controls, 63% vs. 48% cases); in those 20-24 years, the prevalence was ≥97%. Interviewed controls and cases in the 15- to 19- and 20- to 24-year-old age groups were more likely to have a time since start of use of 5+ years. Selection bias factors generally indicated a small underestimation in cellular telephone odds ratios (ORs) ranging from 0.96 to 0.97 for ever-regular use and 0.92 to 0.94 for time since start of use (5+ years), but varied in alternative hypothetical scenarios considered. CONCLUSIONS: Although limited by small numbers of nonrespondent questionnaire respondents, findings generally indicated a small underestimation in cellular telephone ORs due to selective nonparticipation.

Fifteen-year survival of invasive epithelial ovarian cancer in women with BRCA1/2 mutations - the National Israeli Study of Ovarian Cancer.

OBJECTIVE: Compare 5, 10 and 15 year survival in invasive epithelial ovarian cancer, between patients with and without BRCA1/2 germ line mutation in a nonselective group of patients diagnosed during 1994-99. METHODS: The analysis was based on 779 Jewish patients: 229 carriers to the Ashkenazi Jewish founder mutations in BRCA1 (185delAG; 5382insC) and BRCA2 (6174delT); and 550 non-carriers. Clinical characteristics were abstracted from the patients' medical records and vital status was updated through the National Population Registry up to 11/2015. The Kaplan-Meier method, log-rank tests, and Cox-regression model were used for survival analyses. RESULTS: By the end of the follow-up period, (range 1-20 years), 629 (80.7%) deaths occurred. While considerably higher survival was observed during the first 5 years from diagnosis among carriers compared to non-carriers (46.7% vs. 36.2%, p = 0.0004), the survival rates at 15 years were 22.3% vs. 21.8% respectively (p = 0.04). The age-adjusted hazard ratio for all-cause mortality of carriers versus non-carriers was 0.74 (95%CI 0.60-0.91) in the first 5 years. For women who survived 5 and 10 years, the age-adjusted hazard ratios for mortality during 5 additional years, of carriers compared to non-carriers, were 1.38 (95%CI 0.93-2.04) and 1.08 (95%CI 0.61-1.92), respectively. CONCLUSION: The results of this study, with up to 20 years follow-up, support studies with shorter follow-up that suggested that the advantage in survival observed among BRCA1/2 carriers during the first 5 years decreases over time. Clinically, this may have implications for follow-up and therapy, especially of new agents that are particularly effective in BRCA carriers.

Age-specific genome-wide association study in glioblastoma identifies increased proportion of 'lower grade glioma'-like features associated with younger age.

Glioblastoma (GBM) is the most common malignant brain tumor in the United States. Incidence of GBM increases with age, and younger age-at-diagnosis is significantly associated with improved prognosis. While the relationship between candidate GBM risk SNPs and age-at-diagnosis has been explored, genome-wide association studies (GWAS) have not previously been stratified by age. Potential age-specific genetic effects were assessed in autosomal SNPs for GBM patients using data from four previous GWAS. Using age distribution tertiles (18-53, 54-64, 65+) datasets were analyzed using age-stratified logistic regression to generate p values, odds ratios (OR), and 95% confidence intervals (95%CI), and then combined using meta-analysis. There were 4,512 total GBM cases, and 10,582 controls used for analysis. Significant associations were detected at two previously identified SNPs in 7p11.2 (rs723527 [p54-63 = 1.50x10-9 , OR54-63 = 1.28, 95%CI54-63 = 1.18-1.39; p64+ = 2.14x10-11 , OR64+ = 1.32, 95%CI64+ = 1.21-1.43] and rs11979158 [p54-63 = 6.13x10-8 , OR54-63 = 1.35, 95%CI54-63 = 1.21-1.50; p64+ = 2.18x10-10 , OR64+ = 1.42, 95%CI64+ = 1.27-1.58]) but only in persons >54. There was also a significant association at the previously identified lower grade glioma (LGG) risk locus at 8q24.21 (rs55705857) in persons ages 18-53 (p18-53 = 9.30 × 10-11 , OR18-53 = 1.76, 95%CI18-53 = 1.49-2.10). Within The Cancer Genome Atlas (TCGA) there was higher prevalence of 'LGG'-like tumor characteristics in GBM samples in those 18-53, with IDH1/2 mutation frequency of 15%, as compared to 2.1% [54-63] and 0.8% [64+] (p = 0.0005). Age-specific differences in cancer susceptibility can provide important clues to etiology. The association of a SNP known to confer risk for IDH1/2 mutant glioma and higher prevalence of IDH1/2 mutation within younger individuals 18-53 suggests that more younger individuals may present initially with 'secondary glioblastoma.'

The INTEROCC case-control study: risk of meningioma and occupational exposure to selected combustion products, dusts and other chemical agents.

BACKGROUND: Little is known about occupational risk factors for meningioma. OBJECTIVES: To study whether risk of meningioma is associated with several occupational exposures, including selected combustion products, dusts and other chemical agents. METHODS: The INTEROCC study was an international case-control study of brain cancer conducted in seven countries. Data collection by interview included lifetime occupational histories. A job exposure matrix was used to derive estimates of exposure for the 12 agents. ORs for ever versus never exposed and for exposure-response using duration of exposure and cumulative exposure were derived using conditional logistic regression stratified by sex, age group, country/region, adjusted for education. RESULTS: These analyses included 1906 cases and 5565 controls. For 11 of the 12 agents, no excess risk was found for ever exposed. For ever exposure to oil mists, an elevated OR of 1.57 (95% CI 1.10 to 2.22, 51 exposed cases) was found. Statistically significant exposure-response relationships were observed with cumulative exposure (p=0.01) and duration of exposure (p=0.04). Among women, there were also significant trends for cumulative and duration of exposure to asbestos and excesses in the highest exposure categories for formaldehyde. CONCLUSIONS: Most agents examined did not provoke excess risks of meningioma. The main finding from this study is that it is the first study to identify a statistical association between exposure to oil mists and meningioma. This may be a chance finding or could be due to confounding with iron exposure and further research is required to understand whether the relationship is causal.

Recall of mobile phone usage and laterality in young people: The multinational Mobi-Expo study.

OBJECTIVE: To study recall of mobile phone usage, including laterality and hands-free use, in young people. METHODS: Actual mobile phone use was recorded among volunteers aged between 10 and 24 years from 12 countries by the software application XMobiSense and was compared with self-reported mobile phone use at 6 and 18 months after using the application. The application recorded number and duration of voice calls, number of text messages, amount of data transfer, laterality (% of call time the phone was near the right or left side of the head, or neither), and hands-free usage. After data cleaning, 466 participants were available for the main analyses (recorded vs. self-reported phone use after 6 months). RESULTS: Participants were on average 18.6 years old (IQR 15.2-21.8 years). The Spearman correlation coefficients between recorded and self-reported (after 6 months) number and duration of voice calls were 0.68 and 0.65, respectively. Number of calls was on average underestimated by the participants (adjusted geometric mean ratio (GMR) self-report/recorded = 0.52, 95% CI = 0.47-0.58), while duration of calls was overestimated (GMR=1.32, 95%, CI = 1.15-1.52). The ratios significantly differed by country, age, maternal educational level, and level of reported phone use, but not by time of the interview (6 vs. 18 months). Individuals who reported low mobile phone use underestimated their use, while individuals who reported the highest level of phone use were more likely to overestimate their use. Individuals who reported using the phone mainly on the right side of the head used it more on the right (71.1%) than the left (28.9%) side. Self-reported left side users, however, used the phone only slightly more on the left (53.3%) than the right (46.7%) side. Recorded percentage hands-free use (headset, speaker mode, Bluetooth) increased with increasing self-reported frequency of hands-free device usage. Frequent (≥50% of call time) reported headset or speaker mode use corresponded with 17.1% and 17.2% of total call time, respectively, that was recorded as hands-free use. DISCUSSION: These results indicate that young people can recall phone use moderately well, with recall depending on the amount of phone use and participants' characteristics. The obtained information can be used to calibrate self-reported mobile use to improve estimation of radiofrequency exposure from mobile phones.

Cancer risk among Holocaust survivors in Israel-A nationwide study.

BACKGROUND: Holocaust survivors during World War II were exposed to various factors that are associated with cancer risk. The objective of this study was to determine whether Holocaust survivors had an increased risk for developing cancer. METHODS: The study population included 152,622 survivors. The main analysis was based on a comparison between individuals who were entitled to compensation for suffering persecution during the war and individuals who were denied such compensation. A complementary analysis compared survivors who were born in countries governed by Nazi Germany with survivors born in nonoccupied countries. A Cox proportional hazards model was used, with the time at risk of cancer development starting on either January 1, 1960, or the date of immigration to the date of cancer diagnosis or death or the date of last follow-up (December 31, 2006). RESULTS: Cancer was diagnosed in 22.2% of those who were granted compensation versus 16% of those who were denied compensation (P < .0001). Adjusting for birth cohort, sex, country of origin, and period of immigration, both analyses revealed significant increased risks of developing cancer in those who were exposed. For those who were granted versus denied compensation, the hazard ratios were 1.06 (P < .001) for all sites, 1.12 (P = .07) for colorectal cancer, and 1.37 (P = .008) for lung cancer. For those born in occupied countries versus nonoccupied countries, the hazard ratios were 1.08 (P < .001), 1.08 (P = .003), and 1.12 (P = .02), respectively. CONCLUSIONS: The current results, based on a large cohort of Holocaust survivors who were exposed to a variety of severe deprivations, add to the conflicting and sparse knowledge on this issue and support the notion that this group has a small but consistent increase in cancer development. Cancer 2017;123:3335-45. © 2017 American Cancer Society.

Occupational solvent exposure and risk of glioma in the INTEROCC study.

BACKGROUND: The aetiology of glioma remains largely unknown. Occupational solvent exposure has been suggested as a putative cause of glioma, but past studies have been inconsistent. We examined the association between a range of solvents and glioma risk within the INTEROCC project, a study of brain tumours and occupational exposures based on data from seven national case-control studies conducted in the framework of the INTERPHONE study. We also investigated associations according to tumour grade. METHODS: Data from the seven countries were standardised and then combined into one aggregate data set. Pooled odds ratios (ORs) were estimated for adjusted models that included sex, age, country-region of residence and level of educational attainment. Exposures to any solvent or 11 specific solvents or subgroups were assessed using a modified version of the FINJEM job exposure matrix (JEM) specifically developed for the study, called INTEROCC-JEM. RESULTS: Analysis included 2000 glioma cases and 5565 controls. For glioma and ever/never exposure to any solvent, the OR was 0.91 (95% confidence interval: 0.74-1.11). All ORs were <1.0 for specific solvents/subgroups. There were no increases in risk according to high or low grade of tumour. CONCLUSIONS: The results of this study show no consistent associations for any solvent exposures overall or by grade of tumour.

Primary prevention and screening practices among long-term breast cancer survivors.

PURPOSE: Parallel to increasing survival of breast cancer (BC) patients, a need has arisen to characterize the follow-up required to improve and maintain their health. Our study aimed to assess changes in lifestyle habits over time among the study population, compare compliance rates of selected primary and secondary prevention practices between long-term BC survivors and an age-matched comparison group, and identify factors associated with compliance to these practices. METHODS: The study population comprised 250 Israeli BC survivors, diagnosed with BC between 1999 and 2003, without evidence of disease after 8-12 years, and 250 women with no cancer history, individually matched to survivors by age and area of residence. Data collection and analysis were conducted during August 2012-June 2015 and included socio-demographic variables, lifestyle habits, health promotion by the family physician, and participation in screening procedures and prevention measures. RESULTS: Higher performance rates of mammography and colonoscopy among BC survivors were observed, as well as a greater likelihood of receiving an influenza vaccine and undergoing a bone mineral density scan (adjusted-ORs: 7.7, 1.48, 1.42, and 2.59, respectively) compared to controls. Factors identified with compliance to selected practices were age, higher levels of education and income, never smoking, and strenuous physical activity. The survivors adopted healthier lifestyles, which were similar to those of women who never had cancer. CONCLUSIONS: About 10 years after BC diagnosis, the survivors generally comply with primary and secondary prevention practices.

Interactions between occupational exposure to extremely low frequency magnetic fields and chemicals for brain tumour risk in the INTEROCC study.

OBJECTIVES: In absence of clear evidence regarding possible effects of occupational chemical exposures on brain tumour aetiology, it is worthwhile to explore the hypothesis that such exposures might act on brain tumour risk in interaction with occupational exposure to extremely low frequency magnetic fields (ELF). METHODS: INTEROCC is a seven-country (Australia, Canada, France, Germany, Israel, New Zealand and UK), population-based, case-control study, based on the larger INTERPHONE study. Incident cases of primary glioma and meningioma were ascertained from 2000 to 2004. Job titles were coded into standard international occupational classifications and estimates of ELF and chemical exposures were assigned based on job-exposure matrices. Dichotomous indicators of cumulative ELF (≥50th vs <50th percentile, 1-4 year exposure time window) and chemical exposures (ever vs never, 5-year lag) were created. Interaction was assessed on both the additive and multiplicative scales. RESULTS: A total of 1939 glioma cases, 1822 meningioma cases and 5404 controls were included in the analysis, using conditional logistic regression. There was no clear evidence for interactions between ELF and any of the chemical exposures assessed for either glioma or meningioma risk. For glioma, subjects in the low ELF/metal exposed group had a lower risk than would be predicted from marginal effects. Results were similar according to different exposure time windows, to cut-points of exposure or in exposed-only analyses. CONCLUSIONS: There was no clear evidence for interactions between occupational ELF and chemical exposures in relation to glioma or meningioma risk observed. Further research with more refined estimates of occupational exposures is recommended.

Lifetime occupational exposure to metals and welding fumes, and risk of glioma: a 7-country population-based case-control study.

BACKGROUND: Brain tumor etiology is poorly understood. Based on their ability to pass through the blood-brain barrier, it has been hypothesized that exposure to metals may increase the risk of brain cancer. Results from the few epidemiological studies on this issue are limited and inconsistent. METHODS: We investigated the relationship between glioma risk and occupational exposure to five metals - lead, cadmium, nickel, chromium and iron- as well as to welding fumes, using data from the seven-country INTEROCC study. A total of 1800 incident glioma cases and 5160 controls aged 30-69 years were included in the analysis. Lifetime occupational exposure to the agents was assessed using the INTEROCC JEM, a modified version of the Finnish job exposure matrix FINJEM. RESULTS: In general, cases had a slightly higher prevalence of exposure to the various metals and welding fumes than did controls, with the prevalence among ever exposed ranging between 1.7 and 2.2% for cadmium to 10.2 and 13.6% for iron among controls and cases, respectively. However, in multivariable logistic regression analyses, there was no association between ever exposure to any of the agents and risk of glioma with odds ratios (95% confidence intervals) ranging from 0.8 (0.7-1.0) for lead to 1.1 (0.7-1.6) for cadmium. Results were consistent across models considering cumulative exposure or duration, as well as in all sensitivity analyses conducted. CONCLUSIONS: Findings from this large-scale international study provide no evidence for an association between occupational exposure to any of the metals under scrutiny or welding fumes, and risk of glioma.

The Intracranial Distribution of Gliomas in Relation to Exposure From Mobile Phones: Analyses From the INTERPHONE Study.

When investigating the association between brain tumors and use of mobile telephones, accurate data on tumor position are essential, due to the highly localized absorption of energy in the human brain from the radio-frequency fields emitted. We used a point process model to investigate this association using information that included tumor localization data from the INTERPHONE Study (Australia, Canada, Denmark, Finland, France, Germany, Israel, Italy, Japan, New Zealand, Norway, Sweden, and the United Kingdom). Our main analysis included 792 regular mobile phone users diagnosed with a glioma between 2000 and 2004. Similar to earlier results, we found a statistically significant association between the intracranial distribution of gliomas and the self-reported location of the phone. When we accounted for the preferred side of the head not being exclusively used for all mobile phone calls, the results were similar. The association was independent of the cumulative call time and cumulative number of calls. However, our model used reported side of mobile phone use, which is potentially influenced by recall bias. The point process method provides an alternative to previously used epidemiologic research designs when one is including localization in the investigation of brain tumors and mobile phone use.

The Glioma International Case-Control Study: A Report From the Genetic Epidemiology of Glioma International Consortium.

Decades of research have established only a few etiological factors for glioma, which is a rare and highly fatal brain cancer. Common methodological challenges among glioma studies include small sample sizes, heterogeneity of tumor subtypes, and retrospective exposure assessment. Here, we briefly describe the Glioma International Case-Control (GICC) Study (recruitment, 2010-2013), a study being conducted by the Genetic Epidemiology of Glioma International Consortium that integrates data from multiple data collection sites, uses a common protocol and questionnaire, and includes biospecimen collection. To our knowledge, the GICC Study is the largest glioma study to date that includes collection of blood samples, which will allow for genetic analysis and interrogation of gene-environment interactions.