Headache in the international cohort study of mobile phone use and health (COSMOS) in the Netherlands and the United Kingdom

Headache is a common condition with a substantial burden of disease worldwide. Concerns have been raised over the potential impact of long-term mobile phone use on headache due to radiofrequency electromagnetic fields (RF-EMFs). We explored prospectively the association between mobile phone use at baseline (2009-2012) and headache at follow-up (2015-2018) by analysing pooled data consisting of the Dutch and UK cohorts of the Cohort Study of Mobile Phone Use and Health (COSMOS) (N = 78,437). Frequency of headache, migraine, and information on mobile phone use, including use of hands-free devices and frequency of texting, were self-reported. We collected objective operator data to obtain regression calibrated estimates of voice call duration. In the model mutually adjusted for call-time and text messaging, participants in the high category of call-time showed an adjusted odds ratio (OR) of 1.04 (95 % CI: 0.94-1.15), with no clear trend of reporting headache with increasing call-time. However, we found an increased risk of weekly headache (OR = 1.40, 95 % CI: 1.25-1.56) in the high category of text messaging, with a clear increase in reporting headache with increasing texting. Due to the negligible exposure to RF-EMFs from texting, our results suggest that mechanisms other than RF-EMFs are responsible for the increased risk of headache that we found among mobile phone users.

Occupational exposure to organic solvents and the risk of developing testicular germ cell tumors (TESTIS study): Effect of combined exposure assessment on risk estimation

OBJECTIVES

Etiological factors of testicular germ cell tumors (TGCT) remain largely unknown, but a causal role of occupational exposures to solvents has been suggested. Previous studies analyzing these exposures reported discordant results, potentially related to exposure assessment methods. The aim of this study was to investigate the role of occupational exposure to solvents on the risk of developing TGCT among young men.

METHODS

This study examined occupational exposures to solvents and TGCT risk based on the lifetime work histories of 454 cases and 670 controls, aged 18-45 years, of the French national TESTIS case-control study. Solvent exposure was estimated using: (i) exposure assignment by job-exposure matrix (JEM) and (ii) JEM combined with self-reported exposure data from specific questionnaires (SQ) and expert assessment (EA). Odds ratios (OR) and 95% confidence intervals (CI) were estimated using conditional logistic regression models.

RESULTS

Both approaches (JEM and JEM+SQ+EA) showed a consistent association between TGCT and trichloroethylene exposure (exposed versus not exposed; JEM=OR 1.80 [95% confidence interval (CI) 1.12-2.90] and JEM+SQ+EA= OR 2.59 (95% CI 1.42-4.72). Both approaches also observed positive associations with ketone esters and fuels & petroleum-based solvents.

CONCLUSION

The results suggest that some organic solvents might be involved in the pathogenesis of TGCT among occupationally exposed men. The combined use of JEM+SQ+EA seemed to limit misclassification by considering individual exposure variability and is, therefore, an appealing approach to assess occupational exposures in epidemiological studies.

Respirable crystalline silica and lung cancer in community-based studies: impact of job-exposure matrix specifications on exposure-response relationships

OBJECTIVES

The quantitative job-exposure matrix SYN-JEM consists of various dimensions: job-specific estimates, region-specific estimates, and prior expert ratings of jobs by the semi-quantitative DOM-JEM. We analyzed the effect of different JEM dimensions on the exposure-response relationships between occupational silica exposure and lung cancer risk to investigate how these variations influence estimates of exposure by a quantitative JEM and associated health endpoints.

METHODS

Using SYN-JEM, and alternative SYN-JEM specifications with varying dimensions included, cumulative silica exposure estimates were assigned to 16 901 lung cancer cases and 20 965 controls pooled from 14 international community-based case-control studies. Exposure-response relationships based on SYN-JEM and alternative SYN-JEM specifications were analyzed using regression analyses (by quartiles and log-transformed continuous silica exposure) and generalized additive models (GAM), adjusted for age, sex, study, cigarette pack-years, time since quitting smoking, and ever employment in occupations with established lung cancer risk.

RESULTS

SYN-JEM and alternative specifications generated overall elevated and similar lung cancer odds ratios ranging from 1.13 (1st quartile) to 1.50 (4th quartile). In the categorical and log-linear analyses SYN-JEM with all dimensions included yielded the best model fit, and exclusion of job-specific estimates from SYN-JEM yielded the poorest model fit. Additionally, GAM showed the poorest model fit when excluding job-specific estimates.

CONCLUSION

The established exposure-response relationship between occupational silica exposure and lung cancer was marginally influenced by varying the dimensions of SYN-JEM. Optimized modelling of exposure-response relationships will be obtained when incorporating all relevant dimensions, namely prior rating, job, time, and region. Quantitative job-specific estimates appeared to be the most prominent dimension for this general population JEM.

Mobile phone use and brain tumour risk - COSMOS, a prospective cohort study

BACKGROUND

Each new generation of mobile phone technology has triggered discussions about potential carcinogenicity from exposure to radiofrequency electromagnetic fields (RF-EMF). Available evidence has been insufficient to conclude about long-term and heavy mobile phone use, limited by differential recall and selection bias, or crude exposure assessment. The Cohort Study on Mobile Phones and Health (COSMOS) was specifically designed to overcome these shortcomings.

METHODS

We recruited participants in Denmark, Finland, the Netherlands, Sweden, and the UK 2007-2012. The baseline questionnaire assessed lifetime history of mobile phone use. Participants were followed through population-based cancer registers to identify glioma, meningioma, and acoustic neuroma cases during follow-up. Non-differential exposure misclassification was reduced by adjusting estimates of mobile phone call-time through regression calibration methods based on self-reported data and objective operator-recorded information at baseline. Hazard ratios (HR) and 95% confidence intervals (CI) for glioma, meningioma, and acoustic neuroma in relation to lifetime history of mobile phone use were estimated with Cox regression models with attained age as the underlying time-scale, adjusted for country, sex, educational level, and marital status.

RESULTS

264,574 participants accrued 1,836,479 person-years. During a median follow-up of 7.12 years, 149 glioma, 89 meningioma, and 29 incident cases of acoustic neuroma were diagnosed. The adjusted HR per 100 regression-calibrated cumulative hours of mobile phone call-time was 1.00 (95 % CI 0.98-1.02) for glioma, 1.01 (95 % CI 0.96-1.06) for meningioma, and 1.02 (95 % CI 0.99-1.06) for acoustic neuroma. For glioma, the HR for ≥ 1908 regression-calibrated cumulative hours (90th percentile cut-point) was 1.07 (95 % CI 0.62-1.86). Over 15 years of mobile phone use was not associated with an increased tumour risk; for glioma the HR was 0.97 (95 % CI 0.62-1.52).

CONCLUSIONS

Our findings suggest that the cumulative amount of mobile phone use is not associated with the risk of developing glioma, meningioma, or acoustic neuroma.

Prevalent occupational exposures and risk of lung cancer among women: Results from the application of the Canadian Job-Exposure Matrix (CANJEM) to a combined set of ten case-control studies

BACKGROUND

Worldwide, lung cancer is the second leading cause of cancer death in women. The present study explored associations between occupational exposures that are prevalent among women, and lung cancer.

METHODS

Data from 10 case-control studies of lung cancer from Europe, Canada, and New Zealand conducted between 1988 and 2008 were combined. Lifetime occupational history and information on nonoccupational factors including smoking were available for 3040 incident lung cancer cases and 4187 controls. We linked each reported job to the Canadian Job-Exposure Matrix (CANJEM), which provided estimates of probability, intensity, and frequency of exposure to each selected agent in each job. For this analysis, we selected 15 agents (cleaning agents, biocides, cotton dust, synthetic fibers, formaldehyde, cooking fumes, organic solvents, cellulose, polycyclic aromatic hydrocarbons from petroleum, ammonia, metallic dust, alkanes C18+, iron compounds, isopropanol, and calcium carbonate) that had lifetime exposure prevalence of at least 5% in the combined study population. For each agent, we estimated lung cancer risk in each study center for ever-exposure, by duration of exposure, and by cumulative exposure, using separate logistic regression models adjusted for smoking and other covariates. We then estimated the meta-odds ratios using random-effects meta-analysis.

RESULTS AND CONCLUSIONS

None of the agents assessed showed consistent and compelling associations with lung cancer among women. The following agents showed elevated odds ratio in some analyses: metallic dust, iron compounds, isopropanol, and organic solvents. Future research into occupational lung cancer risk factors among women should prioritize these agents.

Risk factors for childhood brain tumours: A systematic review and meta-analysis of observational studies from 1976 to 2022

BACKGROUND

Childhood brain tumours (CBTs) are the leading cause of cancer death in children under the age of 20 years globally. Though the aetiology of CBT remains poorly understood, it is thought to be multifactorial. We aimed to synthesize potential risk factors for CBT to inform primary prevention.

METHODS

We conducted a systematic review and meta-analysis of epidemiological studies indexed in the PubMed, Web of Science, and Embase databases from the start of those resources through 27 July 2023. We included data from case-control or cohort studies that reported effect estimates for each risk factor around the time of conception, during pregnancy and/or during post-natal period. Random effects meta-analysis was used to estimate summary effect sizes (ES) and 95% confidence intervals (CIs). We also quantified heterogeneity (I2) across studies.

FINDINGS

A total of 4040 studies were identified, of which 181 studies (85 case-control and 96 cohort studies) met our criteria for inclusion. Of all eligible studies, 50% (n = 91) were conducted in Europe, 32% (n = 57) in North America, 9% (n = 16) in Australia, 8% (n = 15) in Asia, 1% (n = 2) in South America, and none in Africa. We found associations for some modifiable risk factors including childhood domestic exposures to insecticides (ES 1.44, 95% CI 1.20-1.73) and herbicides (ES 2.38, 95% CI 1.31-4.33). Maternal domestic exposure to insecticides (ES 1.45, 95% CI 1.09-1.94), maternal consumption of cured meat (ES 1.51, 95% CI 1.05-2.17) and coffee ≥ 2 cups/day (ES 1.45, 95% 95% CI 1.07-1.95) during pregnancy, and maternal exposure to benzene (ES 2.22; 95% CI 1.01-4.88) before conception were associated with CBTs in case-control studies. Also, paternal occupational exposure to pesticides (ES 1.48, 95% CI 1.23-1.77) and benzene (ES 1.74, 95% CI 1.10-2.76) before conception and during pregnancy were associated in case-control studies and in combined analysis. On the other hand, assisted reproductive technology (ART) (ES 1.32, 95% CI 1.05-1.67), caesarean section (CS) (ES 1.12, 95% CI 1.01-1.25), paternal occupational exposure to paint before conception (ES 1.56, 95% CI 1.02-2.40) and maternal smoking > 10 cigarettes per day during pregnancy (ES 1.18, 95% CI 1.00-1.40) were associated with CBT in cohort studies. Maternal intake of vitamins and folic acid during pregnancy was inversely associated in cohort studies. Hormonal/infertility treatment, breastfeeding, child day-care attendance, maternal exposure to electric heated waterbed, tea and alcohol consumption during pregnancy were among those not associated with CBT in both case-control and cohort studies.

CONCLUSION

Our results should be interpreted with caution, especially as most associations between risk factors and CBT were discordant between cohort and case-control studies. At present, it is premature for any CBT to define specific primary prevention guidelines.

Nonchromosomal birth defects and risk of childhood acute leukemia: An assessment in 15 000 leukemia cases and 46 000 controls from the Childhood Cancer and Leukemia International Consortium

Although recent studies have demonstrated associations between nonchromosomal birth defects and several pediatric cancers, less is known about their role on childhood leukemia susceptibility. Using data from the Childhood Cancer and Leukemia International Consortium, we evaluated associations between nonchromosomal birth defects and childhood leukemia. Pooling consortium data from 18 questionnaire-based and three registry-based case-control studies across 13 countries, we used multivariable logistic regression models to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for the association between a spectrum of birth defects and leukemia. Our analyses included acute lymphoblastic leukemia (ALL, n = 13 115) and acute myeloid leukemia (AML, n = 2120) cases, along with 46 172 controls. We used the false discovery rate to account for multiple comparisons. In the questionnaire-based studies, the prevalence of birth defects was 5% among cases vs 4% in controls, whereas, in the registry-based studies, the prevalence was 11% among cases vs 7% in controls. In pooled adjusted analyses, there were several notable associations, including (1) digestive system defects and ALL (OR = 2.70, 95% CI: 1.46-4.98); (2) congenital anomalies of the heart and circulatory system and AML (OR = 2.86, 95% CI: 1.81-4.52) and (3) nervous system defects and AML (OR = 4.23, 95% CI: 1.50-11.89). Effect sizes were generally larger in registry-based studies. Overall, our results could point to novel genetic and environmental factors associated with birth defects that could also increase leukemia susceptibility. Additionally, differences between questionnaire- and registry-based studies point to the importance of complementary sources of birth defect phenotype data when exploring these associations.

Strategies to decrease inequalities in cancer therapeutics, care and prevention: Proceedings on a conference organized by the Pontifical Academy of Sciences and the European Academy of Cancer Sciences, Vatican City, February 23-24, 2023

Analyses of inequalities related to prevention and cancer therapeutics/care show disparities between countries with different economic standing, and within countries with high Gross Domestic Product. The development of basic technological and biological research provides clinical and prevention opportunities that make their implementation into healthcare systems more complex, mainly due to the growth of Personalized/Precision Cancer Medicine (PCM). Initiatives like the USA-Cancer Moonshot and the EU-Mission on Cancer and Europe's Beating Cancer Plan are initiated to boost cancer prevention and therapeutics/care innovation and to mitigate present inequalities. The conference organized by the Pontifical Academy of Sciences in collaboration with the European Academy of Cancer Sciences discussed the inequality problem, dependent on the economic status of a country, the increasing demands for infrastructure supportive of innovative research and its implementation in healthcare and prevention programs. Establishing translational research defined as a coherent cancer research continuum is still a challenge. Research has to cover the entire continuum from basic to outcomes research for clinical and prevention modalities. Comprehensive Cancer Centres (CCCs) are of critical importance for integrating research innovations to preclinical and clinical research, as for ensuring state-of-the-art patient care within healthcare systems. International collaborative networks between CCCs are necessary to reach the critical mass of infrastructures and patients for PCM research, and for introducing prevention modalities and new treatments effectively. Outcomes and health economics research are required to assess the cost-effectiveness of new interventions, currently a missing element in the research portfolio. Data sharing and critical mass are essential for innovative research to develop PCM. Despite advances in cancer research, cancer incidence and prevalence is growing. Making cancer research infrastructures accessible for all patients, considering the increasing inequalities, requires science policy actions incentivizing research aimed at prevention and cancer therapeutics/care with an increased focus on patients' needs and cost-effective healthcare.

Cancer mortality in chrysotile miners and millers, Russian Federation: main results (Asbest Chrysotile Cohort-Study)

BACKGROUND

We investigated mortality in workers of the world's largest chrysotile mine and enrichment factories located in the town of Asbest, Russian Federation.

METHODS

This historical cohort study included all workers employed for at least 1 year between 1975 and 2010 and follow-up until the end of 2015. Cumulative exposure to dust was estimated based on workers' complete occupational history linked to dust measurements systematically collected from the 1950s. Exposure to chrysotile fibers was estimated using dust-to-fiber conversion factors. Relative risks (RRs) and 95% confidence intervals (CIs) were estimated as mortality rate ratios in Poisson regression models.

RESULTS

A total of 30 445 (32% women) workers accumulated 721 312 person-years at risk and 11 110 (36%) died. Of the workers, 54% had more than 30 years since their first exposure. We found an exposure-response between cumulative dust and lung cancer mortality in men. No clear association with dust exposure but a modest increase in the highest category of fiber exposure was seen for lung cancer in women. Mesothelioma mortality was increased (RR = 7.64, 95% CI = 1.18 to 49.5, to at least 80 fibers per cm3 years and RR = 4.56, 95% CI = 0.94 to 22.1, to at least 150 mg/m3 years [dust]), based on 13 deaths. For colorectal and stomach cancer, there were inconsistent associations. No associations were seen for laryngeal or ovarian cancer.

CONCLUSION

In this large-scale epidemiological study in the world's largest active asbestos mine, we confirmed an increased risk of mesothelioma with high fiber exposure and an increasing mortality for lung cancer in men with increasing dust exposure. Less clear-cut increased lung cancer mortality was seen in the women. Continued mortality follow-up is warranted.

Parental occupations at birth and risk of adult testicular germ cell tumors in offspring: a French nationwide case-control study

Background

Testicular germ cell tumors (TGCT) are the most frequent cancer in young men in developed countries. Parental occupational exposures during early-life periods are suspected to increase TGCT risk. The objective was to estimate the association between parental occupations at birth and adult TGCT.

Methods

A case-control study was conducted, including 454 TGCT cases aged 18-45 from 20 French university hospitals, matched to 670 controls based on region and year of birth. Data collected from participants included parental jobs at birth coded according to the International Standard Classification of Occupation-1968 and the French nomenclature of activities-1999. Odds ratios (OR) for TGCT and 95% confidence intervals (CI) were estimated using conditional logistic regression, adjusting for TGCT risk factors.

Results

Paternal jobs at birth as service workers (OR = 1.98, CI 1.18-3.30), protective service workers (OR = 2.40, CI 1.20-4.81), transport equipment operators (OR = 1.96, CI 1.14-3.37), specialized farmers (OR = 2.66, CI 1.03-6.90), and maternal jobs as secondary education teachers (OR = 2.27, CI 1.09-4.76) or in secondary education (OR = 2.35, CI 1.13-4.88) were significantly associated with adult TGCT. The risk of seminoma was increased for the above-mentioned paternal jobs and that of non-seminomas for public administration and defence; compulsory social security (OR = 1.99, CI 1.09-3.65); general, economic, and social administration (OR = 3.21, CI 1.23-8.39) for fathers; and secondary education teacher (OR = 4.67, CI 1.87-11.67) and secondary education (OR = 3.50, CI 1.36-9.01) for mothers.

Conclusion

Some paternal jobs, such as service workers, transport equipment operators, or specialized farmers, and maternal jobs in secondary education seem to be associated with an increased risk of TGCT with specific features depending on the histological type. These data allow hypotheses to be put forward for further studies as to the involvement of occupational exposures in the risk of developing TGCT, such as exposure to pesticides, solvents, or heavy metals.

Occupational Benzene Exposure and Lung Cancer Risk: A Pooled Analysis of 14 Case-Control Studies

Rationale: Benzene has been classified as carcinogenic to humans, but there is limited evidence linking benzene exposure to lung cancer. Objectives: We aimed to examine the relationship between occupational benzene exposure and lung cancer. Methods: Subjects from 14 case-control studies across Europe and Canada were pooled. We used a quantitative job-exposure matrix to estimate benzene exposure. Logistic regression models assessed lung cancer risk across different exposure indices. We adjusted for smoking and five main occupational lung carcinogens and stratified analyses by smoking status and lung cancer subtypes. Measurements and Main Results: Analyses included 28,048 subjects (12,329 cases, 15,719 control subjects). Lung cancer odds ratios ranged from 1.12 (95% confidence interval, 1.03-1.22) to 1.32 (95% confidence interval, 1.18-1.48) (Ptrend = 0.002) for groups with the lowest and highest cumulative occupational exposures, respectively, compared with unexposed subjects. We observed an increasing trend of lung cancer with longer duration of exposure (Ptrend < 0.001) and a decreasing trend with longer time since last exposure (Ptrend = 0.02). These effects were seen for all lung cancer subtypes, regardless of smoking status, and were not influenced by specific occupational groups, exposures, or studies. Conclusions: We found consistent and robust associations between different dimensions of occupational benzene exposure and lung cancer after adjusting for smoking and main occupational lung carcinogens. These associations were observed across different subgroups, including nonsmokers. Our findings support the hypothesis that occupational benzene exposure increases the risk of developing lung cancer. Consequently, there is a need to revisit published epidemiological and molecular data on the pulmonary carcinogenicity of benzene.

Lung Cancer Risks Associated with Occupational Exposure to Pairs of Five Lung Carcinogens: Results from a Pooled Analysis of Case-Control Studies (SYNERGY)

BACKGROUND

While much research has been done to identify individual workplace lung carcinogens, little is known about joint effects on risk when workers are exposed to multiple agents.

OBJECTIVES

We investigated the pairwise joint effects of occupational exposures to asbestos, respirable crystalline silica, metals (i.e., nickel, chromium-VI), and polycyclic aromatic hydrocarbons (PAH) on lung cancer risk, overall and by major histologic subtype, while accounting for cigarette smoking.

METHODS

In the international 14-center SYNERGY project, occupational exposures were assigned to 16,901 lung cancer cases and 20,965 control subjects using a quantitative job-exposure matrix (SYN-JEM). Odds ratios (ORs) and 95% confidence intervals (CIs) were computed for ever vs. never exposure using logistic regression models stratified by sex and adjusted for study center, age, and smoking habits. Joint effects among pairs of agents were assessed on multiplicative and additive scales, the latter by calculating the relative excess risk due to interaction (RERI).

RESULTS

All pairwise joint effects of lung carcinogens in men were associated with an increased risk of lung cancer. However, asbestos/metals and metals/PAH resulted in less than additive effects; while the chromium-VI/silica pair showed marginally synergistic effect in relation to adenocarcinoma (RERI: 0.24; CI: 0.02, 0.46; p = 0.05). In women, several pairwise joint effects were observed for small cell lung cancer including exposure to PAH/silica (OR = 5.12; CI: 1.77, 8.48), and to asbestos/silica (OR = 4.32; CI: 1.35, 7.29), where exposure to PAH/silica resulted in a synergistic effect (RERI: 3.45; CI: 0.10, 6.8).

DISCUSSION

Small or no deviation from additive or multiplicative effects was observed, but co-exposure to the selected lung carcinogens resulted generally in higher risk than exposure to individual agents, highlighting the importance to reduce and control exposure to carcinogens in workplaces and the general environment. https://doi.org/10.1289/EHP13380.

Risk of hematological malignancies from CT radiation exposure in children, adolescents and young adults

Over one million European children undergo computed tomography (CT) scans annually. Although moderate- to high-dose ionizing radiation exposure is an established risk factor for hematological malignancies, risks at CT examination dose levels remain uncertain. Here we followed up a multinational cohort (EPI-CT) of 948,174 individuals who underwent CT examinations before age 22 years in nine European countries. Radiation doses to the active bone marrow were estimated on the basis of body part scanned, patient characteristics, time period and inferred CT technical parameters. We found an association between cumulative dose and risk of all hematological malignancies, with an excess relative risk of 1.96 (95% confidence interval 1.10 to 3.12) per 100 mGy (790 cases). Similar estimates were obtained for lymphoid and myeloid malignancies. Results suggest that for every 10,000 children examined today (mean dose 8 mGy), 1-2 persons are expected to develop a hematological malignancy attributable to radiation exposure in the subsequent 12 years. Our results strengthen the body of evidence of increased cancer risk at low radiation doses and highlight the need for continued justification of pediatric CT examinations and optimization of doses.

Mapping the European cancer prevention research landscape: A case for more prevention research funding

Despite the strong evidence of prevention as a prime defence against the disease, the majority of cancer research investment continues to be made in basic science and clinical translational research. Little quantitative data is available to guide decisions on the choice of research priorities or the allocation of research resources. The primary aim of the mapping of the European cancer prevention research landscape presented in this paper is to provide the evidence-base to inform future investments in cancer research. Using bibliometric data to identify funders that are active in prevention research in Europe and in the world, we have identified that 14% of cancer research papers had a focus on prevention research and those were funded by 16% of all the European cancer research funders. An important finding of our study is the lack of research on primary prevention with primary prevention funders accounting for 25% of European cancer prevention funders, meaning that less than 4% of all European cancer research funders identified show an interest in primary prevention. An additional analysis revealed that 7% of European cancer prevention research papers are categorised as implementation projects, meaning that only 1% of all cancer research publications are implementation research in cancer prevention. This paper highlights that the narrow focus on biology and treatment in Europe needs to be widened to include such areas as primary prevention and secondary prevention and a larger concentration on implementation research. These data can help support a more policy-focused cancer research agenda for individual European governments and charitable and philanthropic organisations and stimulate joining efforts across Europe to create a more systematic and structured approach to cancer prevention.

Exposure to pesticides and risk of Hodgkin lymphoma in an international consortium of agricultural cohorts (AGRICOH)

PURPOSE

Some pesticides may increase the risk of certain lymphoid malignancies, but few studies have examined Hodgkin lymphoma (HL). In this exploratory study, we examined associations between agricultural use of 22 individual active ingredients and 13 chemical groups and HL incidence.

METHODS

We used data from three agricultural cohorts participating in the AGRICOH consortium: the French Agriculture and Cancer Cohort (2005-2009), Cancer in the Norwegian Agricultural Population (1993-2011), and the US Agricultural Health Study (1993-2011). Lifetime pesticide use was estimated from crop-exposure matrices or self-report. Cohort-specific covariate-adjusted overall and age-specific (< 40 or ≥ 40 years) hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated using Cox regression and combined using random effects meta-analysis.

RESULTS

Among 316 270 farmers (75% male) accumulating 3 574 815 person-years at risk, 91 incident cases of HL occurred. We did not observe statistically significant associations for any of the active ingredients or chemical groups studied. The highest risks of HL overall were observed for the pyrethroids deltamethrin (meta-HR = 1.86, 95% CI 0.76-4.52) and esfenvalerate (1.86, 0.78-4.43), and inverse associations of similar magnitude were observed for parathion and glyphosate. Risk of HL at ≥ 40 years of age was highest for ever-use of dicamba (2.04, 0.93-4.50) and lowest for glyphosate (0.46, 0.20-1.07).

CONCLUSION

We report the largest prospective investigation of these associations. Nonetheless, low statistical power, a mixture of histological subtypes and a lack of information on tumour EBV status complicate the interpretability of the results. Most HL cases occurred at older ages, thus we could not explore associations with adolescent or young adult HL. Furthermore, estimates may be attenuated due to non-differential exposure misclassification. Future work should aim to extend follow-up and refine both exposure and outcome classification.

Breastfeeding and risk of childhood brain tumors: a report from the Childhood Cancer and Leukemia International Consortium

PURPOSE

Studies report mixed findings regarding the association of breastfeeding with childhood brain tumors (CBT), the leading causes of cancer-related mortality in young people. Our objective was to determine whether breastfeeding is associated with CBT incidence.

METHODS

We pooled data on N = 2610 cases with CBT (including 697 cases with astrocytoma, 447 cases with medulloblastoma/primitive neuroectodermal tumor [PNET], 167 cases with ependymoma) and N = 8128 age- and sex-matched controls in the Childhood Cancer and Leukemia International Consortium. We computed unconditional logistic regression models to estimate the odds ratio (OR) and 95% confidence interval (CI) of CBT, astrocytoma, medulloblastoma/PNET, and ependymoma according to breastfeeding status, adjusting for study, sex, mode of delivery, birthweight, age at diagnosis/interview, maternal age at delivery, maternal educational attainment, and maternal race/ethnicity. We evaluated any breastfeeding versus none and breastfeeding ≥ 6 months versus none. We subsequently performed random effects meta-analysis to confirm our findings, identify potential sources of heterogeneity, and evaluate for outliers or influential studies.

RESULTS

Breastfeeding was reported by 64.8% of control mothers and 64.5% of case mothers and was not associated with CBT (OR 1.04, 95% CI 0.94-1.15), astrocytoma (OR 1.01, 95% CI 0.87-1.17), medulloblastoma/PNET (OR 1.11, 95% CI 0.93-1.32), or ependymoma (OR 1.06, 95% CI 0.81-1.40). Results were similar when we restricted to breastfeeding ≥ 6 months and in meta-analyses.

CONCLUSION

Our data suggest that breastfeeding does not protect against CBT.

Global, regional and national burdens of non-melanoma skin cancer attributable to occupational exposure to solar ultraviolet radiation for 183 countries, 2000-2019: A systematic analysis from the WHO/ILO Joint Estimates of the Work-related Burden of Disease and Injury

BACKGROUND

A World Health Organization (WHO) and International Labour Organization (ILO) systematic review reported sufficient evidence for higher risk of non-melanoma skin cancer (NMSC) amongst people occupationally exposed to solar ultraviolet radiation (UVR). This article presents WHO/ILO Joint Estimates of global, regional, national and subnational occupational exposures to UVR for 195 countries/areas and the global, regional and national attributable burdens of NMSC for 183 countries, by sex and age group, for the years 2000, 2010 and 2019.

METHODS

We calculated population-attributable fractions (PAFs) from estimates of the population occupationally exposed to UVR and the risk ratio for NMSC from the WHO/ILO systematic review. Occupational exposure to UVR was modelled via proxy of occupation with outdoor work, using 166 million observations from 763 cross-sectional surveys for 96 countries/areas. Attributable NMSC burden was estimated by applying the PAFs to WHO's estimates of the total NMSC burden. Measures of inequality were calculated.

RESULTS

Globally in 2019, 1.6 billion workers (95 % uncertainty range [UR] 1.6-1.6) were occupationally exposed to UVR, or 28.4 % (UR 27.9-28.8) of the working-age population. The PAFs were 29.0 % (UR 24.7-35.0) for NMSC deaths and 30.4 % (UR 29.0-31.7) for disability-adjusted life years (DALYs). Attributable NMSC burdens were 18,960 deaths (UR 18,180-19,740) and 0.5 million DALYs (UR 0.4-0.5). Men and older age groups carried larger burden. Over 2000-2019, attributable deaths and DALYs almost doubled.

CONCLUSIONS

WHO and the ILO estimate that occupational exposure to UVR is common and causes substantial, inequitable and growing attributable burden of NMSC. Governments must protect outdoor workers from hazardous exposure to UVR and attributable NMSC burden and inequalities.

Analysis of the Breast Cancer Journey in Namibia

Importance

Breast cancer (BC) is the leading cancer among women in Namibia. Examining the BC journey in this multiracial country where inequalities remain large is needed to inform effective interventions to reduce BC mortality.

Objective

To describe the entire BC journey of Namibian women by race, utilizing the World Health Organization Global Breast Cancer Initiative (GBCI) framework.

Design, Setting, and Participants

This cohort study used the Namibian subset of the African Breast Cancer-Disparities in Outcomes prospective cohort. Participants were all Namibian residents with confirmed incident BC who presented at the main national public oncology center of the Windhoek Central Hospital (WCH). Follow-up started from recruitment (September 8, 2014, to October 5, 2016) and ended up to 3 years after diagnosis (December 13, 2014, to September 27, 2019). Data analysis was conducted from June 2022 to August 2023.

Exposures

Participants' self-reported ethnicities were aggregated into 3 population groups: Black, mixed ancestry, and White.

Main Outcomes and Measures

Three-year overall survival (OS) was examined using Cox models, and summary statistics were used to describe women's BC journey, including GBCI pillar key performance indicators: (1) early stage (TNM I or II) diagnosis (population benchmark ≥60%), (2) prompt diagnosis, ie, 60 days or less to first health care practitioner visit (population benchmark 100%), and (3) completion of recommended multimodal treatment (MT, ie, surgery plus chemotherapy) (population benchmark ≥80%).

Results

Of 405 women, there were 300 (74%) Black (mean [SD] age, 53 [15] years), 49 (12%) mixed ancestry (mean [SD] age, 53 [7] years), and 56 (14%) White (mean [SD] age, 59 [12] years) patients. Three-year OS was lowest in Black women (60% [95% CI, 54%-66%]; mixed ancestry: 80% [95% CI, 65%-89%]; White: 89% [95% CI, 77%-95%]), who had lower prevalence of early stage diagnosis (Black: 37% [95% CI, 31%-42%]; mixed ancestry and White: 75% [95% CI, 66%-83%]) and timely diagnosis (Black: 60% [95% CI, 54%-66%]; mixed ancestry and White: 77% [95% CI, 69%-85%]), while MT completion (Black: 53% [95% CI, 46%-59%]; mixed ancestry and White: 63% [95% CI, 50%-73%]) was low in all women.

Conclusions and Relevance

In this cohort study of 405 Namibian residents with BC, marked racial disparities in survival were paralleled by inequities all along the BC journey. To improve BC survival, interventions are needed to promote earlier diagnosis in Black Namibian women and to increase MT initiation and completion in all women.

Latin America and the Caribbean Code Against Cancer 1st Edition: 17 cancer prevention recommendations to the public and to policy-makers (World Code Against Cancer Framework)

Preventable risk factors are responsible of at least 40% of cases and almost 45% of all cancer deaths worldwide. Cancer is already the leading cause of death in almost half of the Latin American and the Caribbean countries constituting a public health problem. Cost-effective measures to reduce exposures through primary prevention and screening of certain types of cancers are critical in the fight against cancer but need to be tailored to the local needs and scenarios. The Latin America and the Caribbean (LAC) Code Against Cancer, 1st edition, consists of 17 evidence-based recommendations for the general public, based on the most recent solid evidence on lifestyle, environmental, occupational, and infectious risk factors, and medical interventions. Each recommendation is accompanied by recommendations for policymakers to guide governments establishing the infrastructure needed to enable the public adopting the recommendations. The LAC Code Against Cancer has been developed in a collaborative effort by a large number of experts from the region, under the umbrella strategy and authoritative methodology of the World Code Against Cancer Framework. The Code is a structured instrument ideal for cancer prevention and control that aims to raise awareness and educate the public, while building capacity and competencies to policymakers, health professionals, stakeholders, to contribute to reduce the burden of cancer in LAC.

Parental occupational exposure to solvents and risk of developing testicular germ cell tumors among sons: a French nationwide case-control study (TESTIS study)

OBJECTIVES

The etiology of testicular germ cell tumors (TGCT) is suspected to be related to prenatal environmental risk factors. Some solvents have potential endocrine disrupting or carcinogenic properties and may disrupt male genital development in utero. The aim of this study was to examine the association between parental occupational exposure to solvents and TGCT risk among their offspring.

METHODS

A French nationwide case-control study, TESTIS included 454 TGCT cases and 670 controls frequency-matched on region and 5-year age strata. Participants were interviewed via telephone and provided information on parental occupations at birth. Job-exposure matrices (JEM) developed in the French Matgéné program were used to assign exposure to five petroleum-based solvents, five solvents or groups of oxygenated solvents, and five chlorinated solvents. Odds ratios (OR) for TGCT and 95% confidence intervals (CI) were estimated using conditional logistic regression, adjusting for TGCT risk factors.

RESULTS

Occupational exposure to at least one solvent during the year of their son's birth was 41% among fathers and 21% among mothers. Paternal exposure to at least one solvent showed OR 0.89 (95% CI 0.68-1.15). Exposure to perchloroethylene (OR 1.41, 95% CI 0.55-3.61), methylene chloride (OR 1.13, 95% CI 0.54-2.34) and diesel/kerosene/fuel oil (OR 1.17, 95% CI 0.80-1.73) disclosed OR >1 but with low precision. Our results suggest a possible modest increase in non-seminoma risk for sons whose fathers were highly exposed to trichloroethylene (OR 1.44, 95% CI 0.79-2.63). Maternal exposure to at least one solvent showed OR 0.90 (95% CI 0.65-1.24). When stratifying by birth year, men born in the 1970s experienced an increased TGCT risk following maternal exposure to fuels and petroleum-based solvents (OR 2.74, 95% CI 1.11-6.76).

CONCLUSION

Overall, no solid association was found between parental occupational exposure to solvents and TGCT risk. The association found with maternal occupational exposure to fuels and petroleum solvents among older men needs further investigation.

Bladder cancer risk in relation to occupations held in a nationwide case-control study in Iran

Globally, bladder cancer has been identified as one of the most frequent occupational cancers, but our understanding of occupational bladder cancer risk in Iran is less advanced. This study aimed to assess the risk of bladder cancer in relation to occupation in Iran. We used the IROPICAN case-control study data including 717 incident cases and 3477 controls. We assessed the risk of bladder cancer in relation to ever working in major groups of the International Standard Classification of Occupations (ISCO-68) while controlling for cigarette smoking, opium consumption. Logistic regression models were used to estimate odds ratios (ORs) and 95% confidence intervals (CI). In men, decreased ORs for bladder cancer were observed in administrative and managerial workers (OR 0.4; CI: 0.2, 0.9), and clerks (OR 0.6; CI: 0.4, 0.9). Elevated ORs were observed in metal processors (OR 5.4; CI: 1.3, 23.4), and workers in occupations with likely exposure to aromatic amines (OR 2.2; CI: 1.2, 4.0). There was no evidence of interactions between working in aromatic amines-exposed occupations and tobacco smoking or opium use. Elevated risk of bladder cancer in men in metal processors and workers likely exposed to aromatic amines aligns with associations observed outside Iran. Other previously confirmed associations between high-risk occupations and bladder cancer were not observed, possibly due to small numbers or lack of details on exposure. Future epidemiological studies in Iran would benefit from the development of exposure assessment tools such as job exposure matrices, generally applicable for retrospective exposure assessment in epidemiological studies.

Digital interventions to moderate physical inactivity and/or nutrition in young people: a Cancer Prevention Europe overview of systematic reviews

Background

Strategies to increase physical activity (PA) and improve nutrition would contribute to substantial health benefits in the population, including reducing the risk of several types of cancers. The increasing accessibility of digital technologies mean that these tools could potentially facilitate the improvement of health behaviours among young people.

Objective

We conducted a review of systematic reviews to assess the available evidence on digital interventions aimed at increasing physical activity and good nutrition in sub-populations of young people (school-aged children, college/university students, young adults only (over 18 years) and both adolescent and young adults (<25 years)).

Methods

Searches for systematic reviews were conducted across relevant databases including KSR Evidence (www.ksrevidence.com), Cochrane Database of Systematic Reviews (CDSR) and Database of Abstracts of Reviews of Effects (DARE; CRD). Records were independently screened by title and abstract by two reviewers and those deemed eligible were obtained for full text screening. Risk of bias (RoB) was assessed with the Risk of Bias Assessment Tool for Systematic Reviews (ROBIS) tool. We employed a narrative analysis and developed evidence gap maps.

Results

Twenty-four reviews were included with at least one for each sub-population and employing a range of digital interventions. The quality of evidence was limited with only one of the 24 of reviews overall judged as low RoB. Definitions of "digital intervention" greatly varied across systematic reviews with some reported interventions fitting into more than one category (i.e., an internet intervention could also be a mobile phone or computer intervention), however definitions as reported in the relevant reviews were used. No reviews reported cancer incidence or related outcomes. Available evidence was limited both by sub-population and type of intervention, but evidence was most pronounced in school-aged children. In school-aged children eHealth interventions, defined as school-based programmes delivered by the internet, computers, tablets, mobile technology, or tele-health methods, improved outcomes. Accelerometer-measured (Standardised Mean Difference [SMD] 0.33, 95% Confidence Interval [CI]: 0.05 to 0.61) and self-reported (SMD: 0.14, 95% CI: 0.05 to 0.23) PA increased, as did fruit and vegetable intake (SMD: 0.11, 95% CI: 0.03 to 0.19) (review rated as low RoB, minimal to considerable heterogeneity across results). No difference was reported for consumption of fat post-intervention (SMD: -0.06, 95% CI: -0.15 to 0.03) or sugar sweetened beverages(SSB) and snack consumption combined post-intervention (SMD: -0.02, 95% CI:-0.10 to 0.06),or at the follow up (studies reported 2 weeks to 36 months follow-up) after the intervention (SMD:-0.06, 95% CI: -0.15 to 0.03) (review rated low ROB, minimal to substantial heterogeneity across results). Smartphone based interventions utilising Short Messaging Service (SMS), app or combined approaches also improved PA measured using objective and subjective methods (SMD: 0.44, 95% CI: 0.11 to 0.77) when compared to controls, with increases in total PA [weighted mean difference (WMD) 32.35 min per day, 95% CI: 10.36 to 54.33] and in daily steps (WMD: 1,185, 95% CI: 303 to 2,068) (review rated as high RoB, moderate to substantial heterogeneity across results). For all results, interpretation has limitations in terms of RoB and presence of unexplained heterogeneity.

Conclusions

This review of reviews has identified limited evidence that suggests some potential for digital interventions to increase PA and, to lesser extent, improve nutrition in school-aged children. However, effects can be small and based on less robust evidence. The body of evidence is characterised by a considerable level of heterogeneity, unclear/overlapping populations and intervention definitions, and a low methodological quality of systematic reviews. The heterogeneity across studies is further complicated when the age (older vs. more recent), interactivity (feedback/survey vs. no/less feedback/surveys), and accessibility (type of device) of the digital intervention is considered. This underscores the difficulty in synthesising evidence in a field with rapidly evolving technology and the resulting challenges in recommending the use of digital technology in public health. There is an urgent need for further research using contemporary technology and appropriate methods.

Testicular germ cell tumour risk by occupation and industry: a French case-control study - TESTIS

OBJECTIVE

Testicular germ cell tumours (TGCT) are the most common cancer in men of working age and its incidence has increased notably over the past 40 years. Several occupations have been identified as potentially associated with TGCT risk. The aim of this study was to further explore the relationship between occupations, industries and TGCT risk in men aged 18-45 years.

METHODS

The TESTIS study is a multicenter case-control study conducted between January 2015 and April 2018 in 20 of 23 university hospital centers in metropolitan France. A total of 454 TGCT cases and 670 controls were included. Full job histories were collected. Occupations were coded according to the International Standard Classification of Occupation 1968 version (ISCO-1968) and industry according to the 1999 version of Nomenclature d'Activités Française (NAF-1999). For each job held, ORs and 95% CIs were estimated using conditional logistic regression.

RESULTS

A positive association was observed between TGCT and occupation as agricultural, animal husbandry worker (ISCO: 6-2; OR 1.71; 95% CI (1.02 to 2.82)), as well as salesman (ISCO: 4-51; OR 1.84; 95% CI (1.20 to 2.82)). An increased risk was further observed among electrical fitters and related, electrical and electronics workers employed for 2 years or more (ISCO: 8-5; OR≥2 years 1.83; 95% CI (1.01 to 3.32)). Analyses by industry supported these findings.

CONCLUSIONS

Our findings suggest that agricultural, electrical and electronics workers, and salesmen workers experience an increased risk of TGCT. Further research is needed to identify the agents or chemicals in these high-risk occupations which are relevant in the TGCT development.

TRIAL REGISTRATION NUMBER

NCT02109926.

Engaging European society at the forefront of cancer research and care: How discussions at the 5th Gago Conference on European Science policy led to the Heidelberg Manifesto

European cancer research stakeholders met in October 2022 in Heidelberg, Germany, at the 5th Gago conference on European Cancer Policy, to discuss the current cancer research and cancer care policy landscape in Europe. Meeting participants highlighted gaps in the existing European programmes focusing on cancer research, including Europe's Beating Cancer Plan (EBCP), the Mission on Cancer (MoC), Understanding Cancer (UNCAN.eu), and the joint action CRANE, and put forward the next priorities, in the form of the Heidelberg Manifesto for cancer research. This meeting report presents all discussions that shed light on how infrastructures can be effectively shaped for translational, prevention, clinical and outcomes cancer research, with a focus on implementation and sustainability and while engaging patients and the public. In addition, we summarize recommendations on how to introduce frameworks for the digitalization of European cancer research. Finally, we discuss what structures, commitment, and resources are needed to establish a collaborative cancer research environment in Europe to achieve the scale required for innovation.

The contribution of smoking and smokeless tobacco to oesophageal squamous cell carcinoma risk in the African oesophageal cancer corridor: Results from the ESCCAPE multicentre case-control studies

Tobacco use is a well-established risk factor for oesophageal squamous cell carcinoma (ESCC) but the extent of its contribution to the disease burden in the African oesophageal cancer corridor has not been comprehensively elucidated, including by type of tobacco use. We investigated the contribution of tobacco use (smoking and smokeless) to ESCC in Tanzania, Malawi and Kenya. Hospital-based ESCC case-control studies were conducted in the three countries. Incident cases and controls were interviewed using a comprehensive questionnaire which included questions on tobacco smoking and smokeless tobacco use. Logistic regression models were used to estimate odds ratios (OR) and their 95% confidence intervals (CI) of ESCC associated with tobacco, adjusted for age, sex, alcohol use, religion, education and area of residence. One thousand two hundred seventy-nine cases and 1345 controls were recruited between August 5, 2013, and May 24, 2020. Ever-tobacco use was associated with increased ESCC risk in all countries: Tanzania (OR 3.09, 95%CI 1.83-5.23), and in Malawi (OR 2.45, 95%CI 1.80-3.33) and lesser in Kenya (OR 1.37, 95%CI 0.94-2.00). Exclusive smokeless tobacco use was positively associated with ESCC risk, in Tanzania, Malawi and Kenya combined (OR 1.92, 95%CI 1.26-2.92). ESCC risk increased with tobacco smoking intensity and duration of smoking. Tobacco use is an important risk factor of ESCC in Tanzania, Malawi and Kenya. Our study provides evidence that smoking and smokeless tobacco cessation are imperative in reducing ESCC risk.

Digital interventions to moderate alcohol consumption in young people: a Cancer Prevention Europe overview of systematic reviews

Background

Strategies to reduce alcohol consumption would contribute to substantial health benefits in the population, including reducing cancer risk. The increasing accessibility and applicability of digital technologies make these powerful tools suitable to facilitate changes in behaviour in young people which could then translate into both immediate and long-term improvements to public health.

Objective

We conducted a review of systematic reviews to assess the available evidence on digital interventions aimed at reducing alcohol consumption in sub-populations of young people [school-aged children, college/university students, young adults only (over 18 years) and both adolescent and young adults (<25 years)].

Methods

Searches were conducted across relevant databases including KSR Evidence, Cochrane Database of Systematic Reviews (CDSR) and Database of Abstracts of Reviews of Effects (DARE). Records were independently screened by title and abstract and those that met inclusion criteria were obtained for full text screening by two reviewers. Risk of bias (RoB) was assessed with the ROBIS checklist. We employed a narrative analysis.

Results

Twenty-seven systematic reviews were included that addressed relevant interventions in one or more of the sub-populations, but those reviews were mostly assessed as low quality. Definitions of "digital intervention" greatly varied across systematic reviews. Available evidence was limited both by sub-population and type of intervention. No reviews reported cancer incidence or influence on cancer related outcomes. In school-aged children eHealth multiple health behaviour change interventions delivered through a variety of digital methods were not effective in preventing or reducing alcohol consumption with no effect on the prevalence of alcohol use [Odds Ratio (OR) = 1.13, 95% CI: 0.95-1.36, review rated low RoB, minimal heterogeneity]. While in adolescents and/or young adults who were identified as risky drinkers, the use of computer or mobile device-based interventions resulted in reduced alcohol consumption when comparing the digital intervention with no/minimal intervention (-13.4 g/week, 95% CI: -19.3 to -7.6, review rated low RoB, moderate to substantial heterogeneity).In University/College students, a range of E-interventions reduced the number of drinks consumed per week compared to assessment only controls although the overall effect was small [standardised mean difference (SMD): -0.15, 95% CI: -0.21 to -0.09]. Web-based personalised feedback interventions demonstrated a small to medium effect on alcohol consumption (SMD: -0.19, 95% CI: -0.27 to -0.11) (review rated high RoB, minimal heterogeneity). In risky drinkers, stand-alone Computerized interventions reduced short (SMD: -0.17, 95% CI: -0.27 to -0.08) and long term (SMD: -0.17, 95% CI: -0.30 to -0.04) alcohol consumption compared to no intervention, while a small effect (SMD: -0.15, 95% CI: -0.25 to -0.06) in favour of computerised assessment and feedback vs. assessment only was observed. No short-term (SMD: -0.10, 95% CI: -0.30 to 0.11) or long-term effect (SMD: -0.11, 95% CI: -0.53 to 0.32) was demonstrated for computerised brief interventions when compared to counsellor based interventions (review rated low RoB, minimal to considerable heterogeneity). In young adults and adolescents, SMS-based interventions did not significantly reduce the quantity of drinks per occasion from baseline (SMD: 0.28, 95% CI: -0.02 to 0.58) or the average number of standard glasses per week (SMD: -0.05, 95% CI: -0.15 to 0.05) but increased the risk of binge drinking episodes (OR = 2.45, 95% CI: 1.32-4.53, review rated high RoB; minimal to substantial heterogeneity). For all results, interpretation has limitations in terms of risk of bias and heterogeneity.

Conclusions

Limited evidence suggests some potential for digital interventions, particularly those with feedback, in reducing alcohol consumption in certain sub-populations of younger people. However, this effect is often small, inconsistent or diminishes when only methodologically robust evidence is considered. There is no systematic review evidence that digital interventions reduce cancer incidence through alcohol moderation in young people. To reduce alcohol consumption, a major cancer risk factor, further methodologically robust research is warranted to explore the full potential of digital interventions and to form the basis of evidence based public health initiatives.

Environmental exposure to uranium in a population living in close proximity to gold mine tailings in South Africa

BACKGROUND

Gold mining activities in South Africa resulted in contamination of residential environment with uranium-rich wastes from mine tailings. Health of the people living around the mine tailings could be affected by uranium exposure due to its hazardous chemotoxic and radiological properties.

METHODS

We conducted a cross-sectional study to assess i) uranium (U) concentrations in individual hair samples of children and adults living in close proximity to mine tailings in Northeast- Soweto in Johannesburg, South Africa, and ii) the association between U concentrations in hair and various factors, including zone of residence, socio-demographic and housing characteristics. Sampling sites were divided into three zones based on the distance between a dwelling and a cluster of mine tailings (zone 1: <= 500 m, zone 2: 2-3 km away, zone 3: 4-5 km away). U concentrations in hair samples were measured using inductively coupled plasma mass spectrometry. To test the association between U concentrations and selected factors we used robust regression models with log-transformed U concentrations.

RESULTS

Among 128 subjects with available U measurements, 63 (49%) were children (ages 7-15 years) of which 38 were girls, the remaining 65 (51%) were adult females. Mean (median) U concentration in hair samples was 143 (92) µg/kg. In the mutually adjusted analyses, only an inverse association between age and U concentration in hair remained statistically significant, with geometric mean in children being 2.1 times higher compared to adults (P < 0.001). There was no evidence of an association between zones and U concentration (P = 0.42).

CONCLUSIONS

There was little evidence of association between U concentration in hair and distance from the mine tailings within the 5 km range, but overall concentrations were elevated compared to general population samples in other parts of the world. Children had statistically significantly higher geometric mean of uranium concentration in hair compared to adults. The results are important for improvement of mining waste policies and implementation of health monitoring and protective measures in populations at risk.

ARTICLE CATEGORY

Research Article.

Reproductive history and breast cancer survival: Findings from the African breast cancer-Disparities in outcomes cohort and implications of Africa's fertility transition on breast cancer prognosis

Reproductive characteristics are known risk factors for breast cancer but, other than recent birth, their role as prognostic factors is less clear, and has not been studied in Sub-Saharan Africa (SSA). In this setting, we examined whether reproductive factors independently influence breast cancer survival in a subset of the African Breast Cancer-Disparities in Outcomes cohort study. In 1485 women with incident breast cancer recruited between 2014 and 2017, we examined birth cohort changes in reproductive factors, and used Cox models to examine whether reproductive characteristics were associated with all-cause mortality after adjusting for confounders (age, stage, treatment, HIV, and social factors). Four years after diagnosis, 822 (56%) women had died. Median parity was 4 (IQR = 2, 6) and 209 (28%) of premenopausal women had had a recent birth (<3 years prior to cancer diagnosis). Each pregnancy was associated with a 5% increase (95% CI: 2%, 8%) in mortality rates, which held among postmenopausal women (5%, [1%-9%]). Pre-menopausal women with a recent birth had 52% (20%, 92%) higher mortality rates. Fertility trends by birth cohort showed declining parity, increasing age at first birth and declining age at last birth, however the impact of these population-level changes on future average survival was predicted to be very small (<3% absolute gain).

Occupational exposure to nickel and hexavalent chromium and the risk of lung cancer in a pooled analysis of case-control studies (SYNERGY)

There is limited evidence regarding the exposure-effect relationship between lung-cancer risk and hexavalent chromium (Cr(VI)) or nickel. We estimated lung-cancer risks in relation to quantitative indices of occupational exposure to Cr(VI) and nickel and their interaction with smoking habits. We pooled 14 case-control studies from Europe and Canada, including 16 901 lung-cancer cases and 20 965 control subjects. A measurement-based job-exposure-matrix estimated job-year-region specific exposure levels to Cr(VI) and nickel, which were linked to the subjects' occupational histories. Odds ratios (OR) and associated 95% confidence intervals (CI) were calculated by unconditional logistic regression, adjusting for study, age group, smoking habits and exposure to other occupational lung carcinogens. Due to their high correlation, we refrained from mutually adjusting for Cr(VI) and nickel independently. In men, ORs for the highest quartile of cumulative exposure to CR(VI) were 1.32 (95% CI 1.19-1.47) and 1.29 (95% CI 1.15-1.45) in relation to nickel. Analogous results among women were: 1.04 (95% CI 0.48-2.24) and 1.29 (95% CI 0.60-2.86), respectively. In men, excess lung-cancer risks due to occupational Cr(VI) and nickel exposure were also observed in each stratum of never, former and current smokers. Joint effects of Cr(VI) and nickel with smoking were in general greater than additive, but not different from multiplicative. In summary, relatively low cumulative levels of occupational exposure to Cr(VI) and nickel were associated with increased ORs for lung cancer, particularly in men. However, we cannot rule out a combined classical measurement and Berkson-type of error structure, which may cause differential bias of risk estimates.

Response to Toshihide Tsuda, Yumiko Miyano and Eiji Yamamoto [1]

BACKGROUND

Using a toolkit approach, Tsuda et al. critiqued work carried out by or in collaboration with the International Agency for Research on Cancer (IARC/WHO), including the IARC technical publication No. 46 on "Thyroid health monitoring after nuclear accidents" (TM-NUC), the project on nuclear emergency situations and improvement on medical and health surveillance (SHAMISEN), and the IARC-led work on global thyroid cancer incidence patterns as per IARC core mandate.

MAIN BODY

We respond on the criticism of the recommendations of the IARC technical publication No. 46, and of global thyroid cancer incidence evaluation.

CONCLUSION

After nuclear accidents, overdiagnosis can still happen and must be included in informed decision making when providing a system of optimal help for cases of radiation-induced thyroid cancer, to minimize harm to people by helping them avoid diagnostics and treatment they may not need.

Opium use and risk of lung cancer: A multicenter case-control study in Iran

Opium use was recently classified as a human carcinogen for lung cancer by the International Agency for Research on Cancer. We conducted a large, multicenter case-control study evaluating the association between opium use and the risk of lung cancer. We recruited 627 cases and 3477 controls from May 2017 to July 2020. We used unconditional logistic regression analyses to estimate the odds ratios (OR) and 95% confidence intervals (CI) and measured the association between opium use and the risk of lung cancer. The ORs were adjusted for the residential place, age, gender, socioeconomic status, cigarettes, and water pipe smoking. We found a 3.6-fold risk of lung cancer for regular opium users compared to never users (95% CI: 2.9, 4.6). There was a strong dose-response association between a cumulative count of opium use and lung cancer risk. The OR for regular opium use was higher for small cell carcinoma than in other histology (8.3, 95% CI: 4.8, 14.4). The OR of developing lung cancer among opium users was higher in females (7.4, 95% CI: 3.8, 14.5) than in males (3.3, 95% CI: 2.6, 4.2). The OR for users of both opium and tobacco was 13.4 (95% CI: 10.2, 17.7) compared to nonusers of anything. The risk of developing lung cancer is higher in regular opium users, and these results strengthen the conclusions on the carcinogenicity of opium. The association is stronger for small cell carcinoma cases than in other histology.

Development and Validation of the Epidemiological Tattoo Assessment Tool to Assess Ink Exposure and Related Factors in Tattooed Populations for Medical Research: Cross-sectional Validation Study

BACKGROUND

Tattooing, whose popularity is growing worldwide, is an invasive body art that involves the injection of chemical mixtures, the tattoo ink, into the upper layer of the dermis. Although these inks may contain environmental toxins, including known human carcinogens, their long-term health effects are poorly studied. To conduct the urgently required epidemiological studies on tattoos and their long-term health effects, a validated method for assessing the complex tattoo exposure is needed.

OBJECTIVE

We aimed to develop and validate the Epidemiological Tattoo Assessment Tool (EpiTAT), a questionnaire to self-assess tattoo ink exposure in tattooed populations suitable for application in large epidemiological cohort studies.

METHODS

One of 3 preliminary versions of the EpiTAT using one of the alternative tattoo measurement units hand surface, credit card, or body schemes was randomly filled in by tattooed volunteers in Lyon, France. To identify the most suitable unit of tattoo self-assessment, a validation study was conducted with the selected respondents (N=97) to compare the self-assessments of tattoo surface, color, and coverage with validation measurements made by trained study personnel. Intraclass correlation, the Kendall rank correlation, and 2-tailed t tests were used to statistically compare tattoo size, color area, and tattoo coverage separately for each questionnaire version. Participants' opinions on the alternative measurement units were also considered in the overall evaluation. For quality control of the validation measures, digital surface analysis of 62 photographs of selected tattoos was performed using Fiji/ImageJ.

RESULTS

In general, the results revealed overestimation of self-assessed measures compared with validation measures (eg, mean tattooed body surface 1768, SD 1547, cm2 vs 930, SD 1047, cm2, respectively, for hand surface; P<.001) and validation measures compared with digital image analysis (mean individual tattoo surface 147, SD 303.9, cm2 vs 101, SD 154.7, cm2, respectively; P=.05). Although the measurement unit credit card yielded the most accurate measures for all variables of interest, it had a much lower completion rate (78/129, 60.5%) than hand surface (89/104, 85.6%) and body schemes (90/106, 84.9%). Hand surface measured total tattoo size more accurately than body schemes (absolute agreement intraclass correlation coefficient: 0.71 vs 0.64, respectively).

CONCLUSIONS

The final version of the EpiTAT contains 21 items and uses hand surface as a visual unit of measurement. Likert scales are used to assess color and coverage as a proportion of the total tattoo area. The overestimation of tattoo size by self-reporting merits further research to identify potential influential factors or predictive patterns that could be considered when calculating exposure.

Brain cancer after radiation exposure from CT examinations of children and young adults: results from the EPI-CT cohort study

BACKGROUND

The European EPI-CT study aims to quantify cancer risks from CT examinations of children and young adults. Here, we assess the risk of brain cancer.

METHODS

We pooled data from nine European countries for this cohort study. Eligible participants had at least one CT examination before age 22 years documented between 1977 and 2014, had no previous diagnosis of cancer or benign brain tumour, and were alive and cancer-free at least 5 years after the first CT. Participants were identified through the Radiology Information System in 276 hospitals. Participants were linked with national or regional registries of cancer and vital status, and eligible cases were patients with brain cancers according to WHO International Classification of Diseases for Oncology. Gliomas were analysed separately to all brain cancers. Organ doses were reconstructed using historical machine settings and a large sample of CT images. Excess relative risks (ERRs) of brain cancer per 100 mGy of cumulative brain dose were calculated with linear dose-response modelling. The outcome was the first reported diagnosis of brain cancer after an exclusion period of 5 years after the first electronically recorded CT examination.

FINDINGS

We identified 948 174 individuals, of whom 658 752 (69%) were eligible for our study. 368 721 (56%) of 658 752 participants were male and 290 031 (44%) were female. During a median follow-up of 5·6 years (IQR 2·4-10·1), 165 brain cancers occurred, including 121 (73%) gliomas. Mean cumulative brain dose, lagged by 5 years, was 47·4 mGy (SD 60·9) among all individuals and 76·0 mGy (100·1) among people with brain cancer. A significant linear dose-response relationship was observed for all brain cancers (ERR per 100 mGy 1·27 [95% CI 0·51-2·69]) and for gliomas separately (ERR per 100 mGy 1·11 [0·36-2·59]). Results were robust when the start of follow-up was delayed beyond 5 years and when participants with possibly previously unreported cancers were excluded.

INTERPRETATION

The observed significant dose-response relationship between CT-related radiation exposure and brain cancer in this large, multicentre study with individual dose evaluation emphasises careful justification of paediatric CTs and use of doses as low as reasonably possible.

FUNDING

EU FP7; Belgian Cancer Registry; La Ligue contre le Cancer, L'Institut National du Cancer, France; Ministry of Health, Labour and Welfare of Japan; German Federal Ministry of Education and Research; Worldwide Cancer Research; Dutch Cancer Society; Research Council of Norway; Consejo de Seguridad Nuclear, Generalitat de Catalunya, Spain; US National Cancer Institute; UK National Institute for Health Research; Public Health England.

Global and regional estimates of orphans attributed to maternal cancer mortality in 2020

Despite women being disproportionally affected by cancer deaths at young ages, there are no global estimates of the resulting maternal orphans, who experience health and education disadvantages throughout their lives. We estimated the number of children who became maternal orphans in 2020 due to their mother dying from cancer in that year, for 185 countries worldwide and by cause of cancer-related death. Female cancer deaths-by country, cancer type and age (derived from GLOBOCAN estimates)-were multiplied by each woman's estimated number of children under the age of 18 years at the time of her death (fertility data were derived from United Nations World Population Prospects for birth cohort), accounting for child mortality and parity-cancer risk associations. Globally, there were 1,047,000 such orphans. Over half of these were orphans due to maternal deaths from breast (258,000, 25%), cervix (210,000, 20%) and upper-gastrointestinal cancers (136,000, 13%), and most occurred in Asia (48%: India 15%, China 10%, rest of Asia 23%) and Africa (35%). Globally, there were 40 new maternal orphans due to cancer per 100,000 children, with a declining trend with a higher Human Development Index (range: 121 in Malawi to 15 in Malta). An estimated 7 million children were prevalent maternal orphans due to cancer in mid-2020. Accelerating the implementation of the World Health Organization's cervical and breast cancer initiatives has the potential to avert not only millions of preventable female cancer deaths but also the associated, often-overlooked, intergenerational consequences of these deaths.

Lung cancer risk in relation to jobs held in a nationwide case-control study in Iran

BACKGROUND

Globally, lung cancer is the most frequent occupational cancer, but the risk associated with the occupations or occupational environment in Iran is not clear. We aimed to assess occupations with the risk of lung cancer.

METHODS

We used the IROPICAN nationwide case-control study data including 658 incident lung cancer cases and 3477 controls. We assessed the risk of lung cancer in relation to ever working in major groups of International Standard Classification of Occupations, high-risk occupations for lung cancer and duration of employment and lung cancer subtype among construction workers and farmers while controlling for cigarette smoking and opium consumption. We used unconditional regression logistic models to estimate ORs for the association between increased lung cancer risk and occupations.

RESULTS

We observed elevated ORs for lung cancer in male construction workers (OR=1.4; 95% CI: 1.0 to 1.8), petroleum industry workers (OR=3.2; 95% CI: 1.1 to 9.8), female farmers (OR=2.6; 95% CI: 1.3 to 5.3) and female bakers (OR=5.5; 95% CI: 1.0 to 29.8). A positive trend by the duration of employment was observed for male construction workers (p< 0.001). Increased risk of squamous cell carcinoma was observed in male construction workers (OR=1.9; 95% CI: 1.2 to 3.0) and female farmers (OR=4.3; 95% CI: 1.1 to 17.2), who also experienced an increased risk of adenocarcinoma (OR=3.8; 95% CI: 1.4 to 9.9).

DISCUSSION

Although we observed associations between some occupations and lung cancer consistent with the literature, further studies with larger samples focusing on exposures are needed to better understand the occupational lung cancer burden in Iran.

An international report on bacterial communities in esophageal squamous cell carcinoma

The incidence of esophageal squamous cell carcinoma (ESCC) is disproportionately high in the eastern corridor of Africa and parts of Asia. Emerging research has identified a potential association between poor oral health and ESCC. One possible link between poor oral health and ESCC involves the alteration of the microbiome. We performed an integrated analysis of four independent sequencing efforts of ESCC tumors from patients from high- and low-incidence regions of the world. Using whole genome sequencing (WGS) and RNA sequencing (RNAseq) of ESCC tumors from 61 patients in Tanzania, we identified a community of bacteria, including members of the genera Fusobacterium, Selenomonas, Prevotella, Streptococcus, Porphyromonas, Veillonella and Campylobacter, present at high abundance in ESCC tumors. We then characterized the microbiome of 238 ESCC tumor specimens collected in two additional independent sequencing efforts consisting of patients from other high-ESCC incidence regions (Tanzania, Malawi, Kenya, Iran, China). This analysis revealed similar ESCC-associated bacterial communities in these cancers. Because these genera are traditionally considered members of the oral microbiota, we next explored whether there was a relationship between the synchronous saliva and tumor microbiomes of ESCC patients in Tanzania. Comparative analyses revealed that paired saliva and tumor microbiomes were significantly similar with a specific enrichment of Fusobacterium and Prevotella in the tumor microbiome. Together, these data indicate that cancer-associated oral bacteria are associated with ESCC tumors at the time of diagnosis and support a model in which oral bacteria are present in high abundance in both saliva and tumors of some ESCC patients.

Paternal Occupational Exposure to Heavy Metals and Welding Fumes and Testicular Germ Cell Tumours in Sons in France

Testicular cancer is the most common cancer in young men. Its causes are largely unknown, although prenatal occupational and environmental exposures have been suggested. We investigated paternal occupational exposure to heavy metals and welding fumes and the risk of testicular germ cell tumors (TGCT) in their offspring. A total of 454 cases and 670 controls were included from a French nationwide case-control study. The INTEROCC job exposure matrix was used to assign occupational exposures (cadmium, chromium, iron, nickel, lead, and welding fumes) to the fathers' jobs. Odds ratios (ORs) for TGCT were estimated using conditional logistic regression models for frequency-matched sets. Three complementary analytical approaches were used: (1) single-agent analysis, (2) analysis by groups, and (3) principal component analysis (PCA). The proportion of paternal exposure to different heavy metals and welding fumes ranged from 0.7% (cadmium) to 11.3% (lead). Based on PCA, three principal components explained 93.5% of the cumulative variance. No associations were found between heavy metals or welding fumes and TGCT. In this study, paternal occupational exposure to heavy metals or welding fumes was not associated with TGCT development in their sons.

A very-hot food and beverage thermal exposure index and esophageal cancer risk in Malawi and Tanzania: findings from the ESCCAPE case-control studies

BACKGROUND

Consumption of very-hot beverages/food is a probable carcinogen. In East Africa, we investigated esophageal squamous cell carcinoma (ESCC) risk in relation to four thermal exposure metrics separately and in a combined score.

METHODS

From the ESCCAPE case-control studies in Blantyre, Malawi (2017-20) and Kilimanjaro, Tanzania (2015-19), we used logistic regression models adjusted for country, age, sex, alcohol and tobacco, to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for self-reported thermal exposures whilst consuming tea, coffee and/or porridge.

RESULTS

The study included 849 cases and 906 controls. All metrics were positively associated with ESCC: temperature of drink/food (OR 1.92 (95% CI: 1.50, 2.46) for 'very hot' vs 'hot'), waiting time before drinking/eating (1.76 (1.37, 2.26) for <2 vs 2-5 minutes), consumption speed (2.23 (1.78, 2.79) for 'normal' vs 'slow') and mouth burning (1.90 (1.19, 3.01) for ≥6 burns per month vs none). Amongst consumers, the composite score ranged from 1 to 12, and ESCC risk increased with higher scores, reaching an OR of 4.6 (2.1, 10.0) for scores of ≥9 vs 3.

CONCLUSIONS

Thermal exposure metrics were strongly associated with ESCC risk. Avoidance of very-hot food/beverage consumption may contribute to the prevention of ESCC in East Africa.

Time trends in mobile phone use and glioma incidence among males in the Nordic Countries, 1979-2016

INTRODUCTION

In the Nordic countries, the use of mobile phones increased sharply in the mid-1990s especially among middle-aged men. We investigated time trends in glioma incidence rates (IR) with the perspective to inform about the plausibility of brain tumour risks from mobile phone use reported in some case-control studies.

METHODS

We analysed IR of glioma in Denmark, Finland, Norway, and Sweden among men aged 40-69 years, using data from national cancer registries and population statistics during 1979-2016, using log-linear joinpoint analysis. Information on regular mobile phone use and amount of call-time was obtained from major studies of mobile phones in these countries. We compared annual observed incidence with that expected under various risk scenarios to assess which of the reported effect sizes are compatible with the observed IR. The expected numbers of cases were computed accounting for an impact of other factors besides mobile phone use, such as improved cancer registration.

RESULTS

Based on 18,232 glioma cases, IR increased slightly but steadily with a change of 0.1% (95 %CI 0.0%; 0.3%) per year during 1979-2016 among 40-59-year-old men and for ages 60-69, by 0.6 % (95 %CI 0.4; 0.9) annually. The observed IR trends among men aged 40-59 years were incompatible with risk ratios (RR) 1.08 or higher with a 10-year lag, RR ≥ 1.2 with 15-year lag and RR ≥ 1.5 with 20-year lag. For the age group 60-69 years, corresponding effect sizes RR ≥ 1.4, ≥2 and ≥ 2.5 could be rejected for lag times 10, 15 and 20 years.

DISCUSSION

This study confirms and reinforces the conclusions that no changes in glioma incidence in the Nordic countries have occurred that are consistent with a substantial risk attributable to mobile phone use. This particularly applies to virtually all reported risk increases reported by previous case-control studies with positive findings.

Nutritional Status at Diagnosis as Predictor of Survival from Childhood Cancer: A Review of the Literature

Few studies so far have examined the impact of nutritional status on the survival of children with cancer, with the majority of them focusing on hematological malignancies. We summarized published evidence reporting the association of nutritional status at diagnosis with overall survival (OS), event-free survival (EFS), relapse, and treatment-related toxicity (TRT) in children with cancer. Published studies on children with leukemia, lymphoma, and other solid tumors have shown that both under-nourished and over-nourished children at cancer diagnosis had worse OS and EFS. Particularly, the risk of death and relapse increased by 30-50% among children with leukemia with increased body mass index at diagnosis. Likewise, the risk of TRT was higher among malnourished children with osteosarcoma and Ewing sarcoma. Nutritional status seems to play a crucial role in clinical outcomes of children with cancer, thus providing a significant modifiable prognostic tool in childhood cancer management. Future studies with adequate power and longitudinal design are needed to further evaluate the association of nutritional status with childhood cancer outcomes using a more standardized definition to measure nutritional status in this population. The use of new technologies is expected to shed further light on this understudied area and give room to person-targeted intervention strategies.

Measurement of Intermediate Frequency Magnetic Fields Generated by Household Induction Cookers for Epidemiological Studies and Development of an Exposure Estimation Model

INTRODUCTION

Exposure assessment of intermediate frequency (IF) electromagnetic fields (EMFs) is difficult and epidemiological studies are limited. In the present study, we aimed to estimate the exposure of pregnant women to IF-EMFs generated by induction cookers in the household using a questionnaire and discussed its applicability to epidemiological studies.

METHOD

Two main home-visit surveys were conducted: a Phase 1 survey to develop an estimation model and a Phase 2 survey to validate the model. The estimation model included the following variables: wattage, cookware diameter, and distance from the hob center (center of the stove). Four models were constructed to determine the importance of each variable and the general applicability for epidemiological studies. In addition, estimated exposure values were calculated based on the Phase 2 survey questionnaire responses and compared with the actual measured values using the Spearman rank correlation coefficient.

RESULT

The average value of the magnetic field measured in the Phase 1 survey was 0.23 μT (variance: 0.13) at a horizontal distance of 30 cm at the height of the cooking table. The highest validity model was inputted distance from the hob center to the body surface that is variable (correlation coefficient = 0.54, 95% confidence interval: 0.22-0.75). No clear differences were identified in the correlation coefficients for each model (z-value: 0.09-0.18, p-value: 0.86-0.93).

DISCUSSION AND CONCLUSIONS

No differences were found in the validity of the four models. This could be due to the biased wattage of the validation population, and for versatility it would be preferable to use three variables (distance, wattage, and estimation using the diameter of the cookware) whenever possible. To our knowledge, this is the first systematic measurement of magnetic fields generated by more than 70 induction cookers in a real household environment. This study will contribute to finding dose-response relationships in epidemiological studies of intermediate-frequency exposure without the use of instrumentation. One of the limitations of this study is it estimates instantaneous exposure in place during cooking only.

Parental occupational exposure to combustion products, metals, silica and asbestos and risk of childhood leukaemia: Findings from the Childhood Cancer and Leukaemia International Consortium (CLIC)

Parental occupational exposures around conception (father) or during pregnancy (mother) have been hypothesized as potential predisposing factors for childhood leukaemia. We investigated parental exposure to several known occupational carcinogens and childhood leukaemia risk. We conducted a pooled analysis using case-control data from four European countries (3362 childhood leukemia cases and 6268 controls). Parental occupational exposures to polycyclic aromatic hydrocarbons (PAH), diesel engine exhaust (DEE), chromium, nickel, crystalline silica, and asbestos were assessed by a general population job-exposure matrix. We estimated odd ratios (ORs) and 95% confidence intervals (CIs) using unconditional logistic regression models for all childhood leukaemia combined, by leukaemia type (ALL and AML) and by ALL subtype (B-lineage and T-lineage). We found an association between high paternal occupational exposure to crystalline silica and childhood ALL (OR 2.20, CI 1.60-3.01) with increasing trend from no exposure to high exposure (P = <0.001), and also for AML (OR 2.03, CI 1.04-3.97; P for trend = 0.008). ORs were similar for B- and T-lineage ALL. For ALL, ORs were also slightly elevated with wide confidence intervals for high paternal occupational exposure to chromium (OR 1.23, CI 0.77-1.96), and DEE (OR 1.21, CI 0.82-1.77). No associations were observed for paternal exposures to nickel, PAH and asbestos. For maternal occupational exposure we found several slightly elevated odds ratios but mostly with very wide confidence intervals due to low numbers of exposed mothers. This is a first study suggesting an association between fathers' occupational exposure to crystalline silica and an increased risk of childhood leukaemia in their offspring. As this association was driven by certain occupations (field crop farmers and miners) where other potentially relevant exposures like pesticides and radon may also occur, more research is needed to confirm our findings of an association with crystalline silica, and if so, mechanistic studies to understand the pathways.

Residential road traffic and railway noise and risk of childhood cancer: A nationwide register-based case-control study in Denmark

BACKGROUND

The aetiology of most childhood cancers remains poorly understood. We conducted a nationwide register-based case-control study to assess the association between residential road traffic and railway noise exposure and risk of childhood cancers.

METHODS

We identified all cases of first cancers diagnosed in children aged 0-19 years in 1985-2013 from the Danish Cancer Registry (N = 3962) and sampled four individually matched (by sex and date of birth) controls per case (N = 14,790) using the Central Population Register. We estimated time-weighted exposure averages of residential road traffic and railway noise at the most (Lden max) and least (Lden min) exposed façades from birth to index-date (for additional analysis: in utero period) based on the individual address history for the respective time windows. We fitted conditional logistic regression models to estimate odds ratios (OR) and their 95% confidence intervals (CI).

RESULTS

ORs varied by noise estimate and cancer type, with generally wide CIs mostly including 1.00. We found a tendency of higher ORs with increasing railway and road traffic noise for Hodgkin lymphoma (ORs for railway and road Lden min were 1.63 (95% CI 1.00; 2.66) and 1.14 (95% CI 0.87; 1.48) per 10 dB), as well as a tendency of higher ORs with increasing railway noise for non-Hodgkin lymphoma. For embryonal CNS tumours and astrocytoma and other glioma we observed also some weak suggestions of a positive association. Analysing exposure to traffic noise in utero revealed similar patterns to those of the main analyses.

CONCLUSIONS

This nationwide study with minimal risk of bias suggests no strong associations between traffic noise and risk of most childhood cancers. We found however some suggestive evidence for a positive association with Hodgkin lymphoma, non-Hodgkin lymphoma and some CNS tumours. Further research is warranted to confirm these associations in other populations and elucidate the underlying biological mechanisms.

Coverage and Acceptability of Mobile Phone Messages for Cancer Prevention: a Population-Based Study in a Latin American Country

Mobile health (m-health) has shown positive effects on disease prevention; however, several factors might influence its effectiveness, particularly in low- and middle-income countries. Randomized trials provide data with high internal validity but no major information on population impact. We conducted a pilot population-based study to assess the feasibility of cancer prevention through m-health in a Latin American population. A sample of affiliates to a health insurance company in Colombia was randomly selected and assigned to receive a short message service (SMS) or voice messages (VMS) during 4 weeks; weekly frequencies 2 and 7. Baseline and post-intervention surveys were conducted. Overall, 797 affiliates were contacted (SMS 393, VMS 404) but only 15.3% and 24.8% enrolled, respectively. Over 80% acceptability was observed among participants for all items evaluated (usefulness, understandability, timing, and frequency); however, 2-VMS per week was the only frequency consistent with the declared number of messages received and listened. Other frequencies resulted in high reception recall but low willingness to read/listen the messages. The willingness to be part of future programs was 20.0%. The gap between declared acceptability and practice, low participation rates, and low willingness to read/listen messages indicate m-health should be part of multicomponent interventions and should not be conceived as the sole intervention.