Environmental and occupational causes of cancer: new evidence 2005-2007

DNA damage signalling from the placenta to foetal blood as a potential mechanism for childhood leukaemia initiation

For many diseases with a foetal origin, the cause for the disease initiation remains unknown. Common childhood acute leukaemia is thought to be caused by two hits, the first in utero and the second in childhood in response to infection. The mechanism for the initial DNA damaging event are unknown. Here we have used in vitro, ex vivo and in vivo models to show that a placental barrier will respond to agents that are suspected of initiating childhood leukaemia by releasing factors that cause DNA damage in cord blood and bone marrow cells, including stem cells. We show that DNA damage caused by in utero exposure can reappear postnatally after an immune challenge. Furthermore, both foetal and postnatal DNA damage are prevented by prenatal exposure of the placenta to a mitochondrially-targeted antioxidant. We conclude that the placenta might contribute to the first hit towards leukaemia initiation by bystander-like signalling to foetal haematopoietic cells.

Lung cancer risk assessment for workers exposed to polycyclic aromatic hydrocarbons in various industries

BACKGROUND

Millions of workers are exposed to carcinogenic polycyclic aromatic hydrocarbon (PAH) mixtures. The toxicity of PAH mixtures is variable and depends on the composition of the mixture, which is related to the emission sources. Although several indicators exist, the cancer risk estimation associated with occupational exposure to PAHs is poorly known.

OBJECTIVES

To assess the risk of lung cancer associated with PAHs in several industries using the atmospheric concentrations of benzo[a]pyrene (BaP) as a proxy.

METHODS

A total of 93 exposure groups belonging to 9 industries were investigated. Eight indicators found in the literature were compared to assess risks. A consensual indicator was used to estimate lung cancer risks.

RESULTS

Approximately 30% of the exposure groups were above the maximal risk level of the European Union (10^-4). The risk probabilities were >10^-3 for coke and silicon production; >10^-4 for the manufacturing of carbon products and aluminum production; >10^-5 for foundries and combustion processes; >10^-6 for the use of lubricating oils and engine exhaust emissions; and >10^-7 for bitumen. The risk probabilities were highly variable within industries (from 1 to 1000 likelihood). A total of 27 (95% CI: 0.1-54) contemporary additional lung cancer cases could be expected per year in the French exposed population based on estimations using published data.

CONCLUSION

This study provides an overview of cancer risk estimation in many industries. Despite efforts and changes that had been made to decrease risks, PAHs remain a sanitary threat for people exposed to these pollutants in occupational environments.

Determinants of pesticide concentrations in silicone wristbands worn by Latina adolescent girls in a California farmworker community: The COSECHA youth participatory action study

Personal exposure to pesticides has not been well characterized, especially among adolescents. We used silicone wristbands to assess pesticide exposure in 14 to 16 year old Latina girls (N = 97) living in the agricultural Salinas Valley, California, USA and enrolled in the COSECHA (CHAMACOS of Salinas Examining Chemicals in Homes and Agriculture) Study, a youth participatory action study in an agricultural region of California. We determined pesticide concentrations (ng/g/day) in silicone wristbands worn for one week using gas chromatography electron capture detection and employed gas chromatography mass spectrometry to determine the presence or absence of over 1500 chemicals. Predictors of pesticide detections and concentrations were identified using logistic regression, Wilcoxon rank sum tests, and Tobit regression models. The most frequently detected pesticides in wristbands were fipronil sulfide (87%), cypermethrin (56%), dichlorodiphenyldichloroethylene (DDE) (56%), dacthal (53%), and trans-permethrin (52%). Living within 100 m of active agricultural fields, having carpeting in the home, and having an exterminator treat the home in the past six months were associated with higher odds of detecting certain pesticides. Permethrin concentrations were lower for participants who cleaned their homes daily (GM: 1.9 vs. 6.8 ng/g/day, p = 0.01). In multivariable regression models, participants with doormats in the entryway of their home had lower concentrations (p < 0.05) of cypermethrin (87%), permethrin (99%), fipronil sulfide (69%) and DDE (75%). The results suggest that both nearby agricultural pesticide use and individual behaviors are associated with pesticide exposures.

Risk of Primary Neuroendocrine Pancreatic Tumor After a First Primary Cancer: A US Population-Based Study

OBJECTIVE

This study aimed to describe the relative and excess risk of pancreatic neuroendocrine tumor (NET) at least 6 months after the first primary cancer (FPC) among the US population.

METHODS

Surveillance, Epidemiology, and End-Results Program data were analyzed for patients diagnosed as having FPC from 2000 to 2015 (n = 4,008,092). Standardized incidence ratios, excess risk, and average time to diagnosis of a second primary pancreatic NET were reported by FPC site, stratified by sex and receipt of radiotherapy and chemotherapy.

RESULTS

Risk of pancreatic NET was significantly higher after FPC at any site, any solid tumor (standardized incidence ratios, 1.3; 95% confidence interval, 1.2-1.5), pancreas, thymus, small intestine, liver, stomach, kidney, lung, and female breast. Excess incidence of pancreatic NET was highest among those with FPC (especially NET) of the pancreas, bladder, thymus, and female breast; those who received radiotherapy/chemotherapy for bladder, melanoma, and stomach cancers; and those who received chemotherapy for uterine, cervical, prostate, and other genital cancers. Time to diagnosis was shortest after pancreatic, liver, lung, and stomach cancer.

CONCLUSIONS

Cancer survivors have increased risk and excess incidence of primary pancreatic NET compared with the population, particularly for certain primary sites. High-risk patients should receive regular follow-up screenings, counseling to reduce carcinogen exposure, and lifestyle interventions.

Usual adult occupation and risk of prostate cancer in West African men: the Ghana Prostate Study

OBJECTIVES

Established prostate cancer (PCa) risk factors include age, family history of PCa and African ancestry. Studies, mostly among highly screened, predominantly European ancestral populations, suggest that employment in certain occupations (eg, farming, military) may also have an increased risk for PCa. Here, we evaluated the association between usual adult occupation and PCa risk in Ghanaian men, a population with historically low rates of PCa screening.

METHODS

The Ghana Prostate Study is a case-control study of PCa that was conducted from 2004 to 2012 in 749 cases and 964 controls. In-person interviews were conducted to collect information from participants, including longest held job. Industrial hygienists classified job titles into occupational categories. Unconditional logistic regression was used to calculate ORs and 95% CIs for the association between longest held job and PCa risk (overall, aggressive (Gleason≥7)), controlling for potential confounders.

RESULTS

Risk was increased among men in management (overall PCa OR=2.2, 95% CI 1.4 to 3.2; aggressive PCa OR=2.2, 95% CI 1.3 to 3.5) and military occupations (overall PCa OR=3.4, 95% CI 1.7 to 7.0; aggressive PCa OR=3.5, 95% CI 1.5 to 8.3). Risks were also elevated for management and military-specific jobs based on 3-digit level Standard Occupational Classification definitions. Sensitivity analyses accounting for access to medical care did not show significant differences.

CONCLUSIONS

Our study provides some evidence for increased risk of PCa among men in management and military occupations, which is consistent with the published literature. Additional research is needed to clarify the drivers of the associations between these occupations and PCa.

Genotoxic Effects of Exposure to Gasoline Fumes on Petrol Pump Workers

Background:

Petrol pump workers are occupationally exposed to gasoline and its fumes consisting of several mutagenic chemicals.

Objective:

To evaluate the genotoxic effects of exposure to gasoline fumes on petrol pump workers.

Methods:

The study groups included 70 petrol pump workers (exposed group) and 70 healthy age-matched individuals with no known exposure (comparison group). Buccal micronucleus cytome assay (BMCyt) was performed to check the genotoxicity caused due to inhalation of gasoline fumes.

Results:

The frequencies of micronucleated cells, nuclear bud, condensed chromatin cells, karyorrhectic cells, pyknotic cells, and karyolytic cells were significantly higher in the exposed workers compared to the comparison group.

Conclusion:

Exposure to gasoline fumes is associated with increased frequency of cell abnormalities. This may lead to various health consequences including cancer in those occupationally exposed to gasoline fumes.

Outdoor air pollution, green space, and cancer incidence in Saxony: a semi-individual cohort study

BACKGROUND

There are a few epidemiological studies that (1) link increased ambient air pollution (AP) with an increase in lung cancer incidence rates and (2) investigate whether residing in green spaces could be protective against cancer. However, it is completely unclear whether other forms of cancer are also affected by AP and if residential green spaces could lower cancer incidence rates in general. Therefore, the objective was to estimate whether AP and green space are associated with several cancer types.

METHODS

The analysis was based on routine health care data from around 1.9 million people from Saxony who were free of cancer in 2008 and 2009. Incident cancer cases (2010-2014) of mouth and throat, skin (non-melanoma skin cancer - NMSC), prostate, breast, and colorectum were defined as: (1) one inpatient diagnosis, or (2) two outpatient diagnoses in two different quarters within one year and a specific treatment or death within two quarters after the diagnosis. Exposures, derived from freely available 3rd party data, included particulate matter with aerodynamic diameter of less than 10 μm (PM10) and nitrogen dioxide (N02) as well as green space (Normalized Difference Vegetation Index - NDVI). Associations between air pollutants, green space, and cancer incidence were assessed by multilevel Poisson models. Age, sex, physician contacts, short- and long-term unemployment, population density, and having an alcohol-related disorder were considered as potential confounders.

RESULTS

Three thousand one hundred seven people developed mouth and throat cancer, 33,178 NMSC, 9611 prostate cancer, 9577 breast cancer, and 11,975 colorectal cancer during the follow-up period (2010-2014). An increase in PM10 of 10 μg/m3 was associated with a 53% increase in relative risk (RR) of mouth and throat cancer and a 52% increase in RR of NMSC. Prostate and breast cancer were modestly associated with PM10 with an increase in RR of 23 and 19%, respectively. The associations with N02 were in the same direction as PM10 but the effect estimates were much lower (7-24%). A 10% increase in NDVI was most protective of mouth and throat cancer (- 11% RR) and of NMSC (- 16% RR). Colorectal cancer was not affected by any of the exposures.

CONCLUSIONS

In addition to the studies carried out so far, this study was able to provide evidence that higher ambient AP levels increase the risk of mouth and throat cancer as well as of NMSC and that a higher residential green space level might have a protective effect for NMSC in areas with low to moderate UV intensity. Nevertheless, we cannot rule out residual confounding by socioeconomic or smoking status.

Outdoor air pollution, green space, and cancer incidence in Saxony: a semi-individual cohort study

BACKGROUND

There are a few epidemiological studies that (1) link increased ambient air pollution (AP) with an increase in lung cancer incidence rates and (2) investigate whether residing in green spaces could be protective against cancer. However, it is completely unclear whether other forms of cancer are also affected by AP and if residential green spaces could lower cancer incidence rates in general. Therefore, the objective was to estimate whether AP and green space are associated with several cancer types.

METHODS

The analysis was based on routine health care data from around 1.9 million people from Saxony who were free of cancer in 2008 and 2009. Incident cancer cases (2010-2014) of mouth and throat, skin (non-melanoma skin cancer - NMSC), prostate, breast, and colorectum were defined as: (1) one inpatient diagnosis, or (2) two outpatient diagnoses in two different quarters within one year and a specific treatment or death within two quarters after the diagnosis. Exposures, derived from freely available 3rd party data, included particulate matter with aerodynamic diameter of less than 10 μm (PM₁₀) and nitrogen dioxide (N0₂) as well as green space (Normalized Difference Vegetation Index - NDVI). Associations between air pollutants, green space, and cancer incidence were assessed by multilevel Poisson models. Age, sex, physician contacts, short- and long-term unemployment, population density, and having an alcohol-related disorder were considered as potential confounders.

RESULTS

Three thousand one hundred seven people developed mouth and throat cancer, 33,178 NMSC, 9611 prostate cancer, 9577 breast cancer, and 11,975 colorectal cancer during the follow-up period (2010-2014). An increase in PM₁₀ of 10 μg/m³ was associated with a 53% increase in relative risk (RR) of mouth and throat cancer and a 52% increase in RR of NMSC. Prostate and breast cancer were modestly associated with PM₁₀ with an increase in RR of 23 and 19%, respectively. The associations with N0₂ were in the same direction as PM₁₀ but the effect estimates were much lower (7-24%). A 10% increase in NDVI was most protective of mouth and throat cancer (- 11% RR) and of NMSC (- 16% RR). Colorectal cancer was not affected by any of the exposures.

CONCLUSIONS

In addition to the studies carried out so far, this study was able to provide evidence that higher ambient AP levels increase the risk of mouth and throat cancer as well as of NMSC and that a higher residential green space level might have a protective effect for NMSC in areas with low to moderate UV intensity. Nevertheless, we cannot rule out residual confounding by socioeconomic or smoking status.

Assessing cancer risk factors faced by an Ancestral Puebloan population in the North American Southwest

Ancestral Puebloan people in the North American Southwest suffered high rates of disease, poor health, and early age-at-death. Four individuals with skeletal expressions of cancer were found in a pre-Columbian population in the Taos Valley - Reports of malignant neoplasms in the archaeological record are uncommon and their presence in four of 82 individuals is a high occurrence. This study continues Whitley and Boyer's (2012) research testing whether concentrations of ionizing radiation were sufficiently high to induce cancer and related health issues. Access to a preserved and partly reconstructed subterranean pit structure inhabited between AD 1120 and 1170, allows us to test radon concentrations in a residential dwelling. This study found radon occurring in high levels, 19.4-20.3 pCi/L (717.8-751.1 Bq/m3) within the structure. Epidemiological reports are inconsistent when linking specific cancers and radon exposure. However, this study can control for many of the confounding factors plaguing other studies, provide unique data that have the potential to initiate dialogue on the etiology of neoplastic disease in the American Southwest, and add new dimensions to the study of the living conditions and health of the Ancestral Puebloans and their descendants.

Occupational Exposures and Health Outcomes Among Immigrants in the USA

PURPOSE OF REVIEW

Immigrants experience higher rates of occupational injury and fatality than their native-born counterparts. This review summarizes the current data related to occupational/environmental exposures and explores potential reasons for the disparities.

RECENT FINDINGS

Immigrant workers are employed in sectors that expose them to dangerous working conditions. They experience increased risk for exposure to heat, pesticides, hazardous chemicals, and cleaning agents, as well as physical hazards such as falls. Immigrant workers are at increased risk for occupational injury and fatality due to the nature of the work they traditionally perform, a lack of enforced safety regulations, and limited access to health care or worker's compensation benefits.

Review of refractory ceramic fiber (RCF) toxicity, epidemiology and occupational exposure

This literature review on refractory ceramic fibers (RCF) summarizes relevant information on manufacturing, processing, applications, occupational exposure, toxicology and epidemiology studies. Rodent toxicology studies conducted in the 1980s showed that RCF caused fibrosis, lung cancer and mesothelioma. Interpretation of these studies was difficult for various reasons (e.g. overload in chronic inhalation bioassays), but spurred the development of a comprehensive product stewardship program under EPA and later OSHA oversight. Epidemiology studies (both morbidity and mortality) were undertaken to learn more about possible health effects resulting from occupational exposure. No chronic animal bioassay studies on RCF have been conducted since the 1980s. The results of the ongoing epidemiology studies confirm that occupational exposure to RCF is associated with the development of pleural plaques and minor decrements in lung function, but no interstitial fibrosis or incremental lung cancer. Evidence supporting a finding that urinary tumors are associated with RCF exposure remains, but is weaker. One reported, but unconfirmed, mesothelioma was found in an individual with prior occupational asbestos exposure. An elevated SMR for leukemia was found, but was absent in the highly exposed group and has not been observed in studies of other mineral fibers. The industry will continue the product stewardship program including the mortality study.

Aspirin and non-steroidal anti-inflammatory drugs use reduce gastric cancer risk: A dose-response meta-analysis

Background

The association between non-steroidal anti-inflammatory drugs (NSAIDs) and gastric cancer (GC) risk is controversial. The aim of this study is to evaluate the chemopreventive effect of NSAIDs for GC.

Methods

A literature search was performed for relevant studies using the PubMed and Embase database (up to March 2016). Risk ratios (RRs) and 95% confidence intervals (CIs) were used as the effect measures. The dose–response analysis and subgroup analysis were also performed.

Results

Twenty-four studies were included. Our results indicated that NSAIDs could reduce GC risk (any NSAIDs: RR=0.78, 96%CI=0.72-0.85; aspirin: RR=0.70, 95%CI=0.62-0.80; non-aspirin NSAIDs: RR=0.86, 95%CI=0.80-0.94), especially for non-cardia GC risk. Moreover, the dose-response analysis indicated the risk of GC decreased by 11% and 5% for 2 years increment of any NSAIDs and aspirin use, respectively. There were nonlinear relationships between the frequency of any NSAIDs use and aspirin use and GC risk (P for non-linearity<0.01), with a threshold effect of 5 times/week. A monotonically decreasing trend was observed only for the frequency of less than 5 times/week.

Conclusions

Our results indicate that NSAIDs is inversely associated with GC risk, especially for non-cardia GC risk. NSAIDs use may become a feasible approach to prevent GC.

Sulforaphane epigenetically demethylates the CpG sites of the miR-9-3 promoter and reactivates miR-9-3 expression in human lung cancer A549 cells

Increasing evidence suggests that epigenetic aberrations contribute to the development and progression of cancers such as lung cancer. The promoter region of miR-9-3 was recently found to be hypermethylated in lung cancer, resulting in down-regulation of miR-9-3 and poor patient prognosis. Sulforaphane (SFN), a natural compound that is obtained from cruciferous vegetables, has potent anticancer activities. In this study, we aimed to investigate the effect of SFN on restoring the miR-9-3 level in lung cancer A549 cells through epigenetic regulation. DNA methylation of the miR-9-3 promoter was examined using bisulfite genomic sequencing and methylated DNA immunoprecipitation analysis. The expression levels of miR-9-3 and several epigenetic modifying enzymes were measured using quantitative real-time polymerase chain reaction and Western blotting, respectively. The transcriptional activity of the miR-9-3 promoter was evaluated by patch methylation, and histone modifications were analyzed using chromatin immunoprecipitation (ChIP) assays. We found that CpG methylation was reduced in the miR-9-3 promoter and that miR-9-3 expression was increased after 5 days of treatment with SFN. In vitro methylation analysis showed that the methylated recombinant construct exhibited lower luciferase reporter activity than the unmethylated counterpart. ChIP assays revealed that SFN treatment increased H3K4me1 enrichment at the miR-9-3 promoter. Furthermore, SFN treatment attenuated enzymatic DNMT activity and DNMT3a, HDAC1, HDAC3, HDAC6 and CDH1 protein expression. Taken together, these findings indicate that SFN may exert its chemopreventive effects partly through epigenetic demethylation and restoration of miR-9-3.

Activation of Aryl Hydrocarbon Receptor Suppresses Invasion of Esophageal Squamous Cell Carcinoma Cell Lines

Aims and Background

Esophageal cancer is the eighth most common malignancy and sixth leading cause of cancer deaths in the world. Recent studies have shown the potential role of the aryl hydrocarbon receptor (AhR) in tumor development; however, little is known about its role in esophageal squamous cell carcinoma. In the present study, we evaluated AhR expression in esophageal tumor tissues as well as cell lines and investigated the effects of AhR activation by its agonist BNF on esophageal squamous cell carcinoma invasion using Eca109 and TE-13 cells as a model.

Methods

Western blotting was performed to detect the AhR and CYP1A1 protein expression. Transwell migration assays were carried out to study the effects of BNF on esophageal squamous cell carcinoma cell invasion. AhR-specific siRNA was used to knock down the expression of AhR protein.

Results

Our results showed that AhR was highly expressed in esophageal squamous cell carcinoma tissues and cell lines when compared with its expression in normal tissue. AhR siRNA robustly decreased AhR protein expression in both Eca109 and TE-13 cells. BNF significantly inhibited invasion of human esophageal squamous cell carcinoma cells via activation of AhR.

Conclusions

The obtained results provide critical information on the roles of BNF in mediating esophageal squamous cell carcinoma invasion. This information could be useful for future therapeutic intervention in this lethal human disease.

The association between non-Hodgkin lymphoma and organophosphate pesticides exposure: A meta-analysis

Several epidemiological studies show the association between organophosphate pesticides (OPs) and the risk of non-Hodgkin lymphoma (NHL), yet various research results remain controversial. To explore the hazard of OPs exposure to human health, three kinds of OPs (Terbufos, Malathion, and Diazinon) that are non-halogenated aliphatic compounds were included in the meta-analysis. We searched PubMed and Web of Science Databases for articles published from 1985 to February 2017. The databases were also searched for eligible studies through a manual references search. The random-effect model was utilized to compute the odds ratios (ORs) and 95% confident intervals (CIs). A total of ten observational studies (five cohort, four case-control, and one nested case-control) were included in our meta-analysis, with a pooled OR of 1.22 (95% CI 1.04 to 1.43) of Malathion, Terbufos and Diazinion. The general heterogeneity for OR was moderate (P_h = 0.032, I² = 41.2%). The OR estimates in the subset analyses were utilized to compare the association between the three kinds of OPs and NHL; Terbufos (OR = 1.07, 95% CI 0.85 to 1.36) and Malathion (OR = 1.17, 95% CI 0.82 to 1.67) had a statistically non-significant relationship, whereas Diazinon (OR = 1.39, 95% CI 1.11 to 1.73) was significantly associated with an increased NHL risk. Because immune dysfunction was thought to increase NHL risk, the toxicity levels in the immune system of the three types of OPs were compared. Malathion attacked immune cells via a direct effect and Diazinon disrupted the neuro-immune system, which involves the cholinergic system of lymphocytes via indirect immune damage, whereas an immunotoxic effect involving Terbufos was not reported. Overall, the present meta-analysis indicated a statistically significant association between Diazinon exposure and NHL risk.

Risk of early-onset prostate cancer associated with occupation in the Nordic countries

BACKGROUND

Early-onset prostate cancer is often more aggressive and may have a different aetiology than later-onset prostate cancer, but has been relatively little studied to date. We evaluated occupation in relation to early- and later-onset prostate cancer in a large pooled study.

METHODS

We used occupational information from census data in five Nordic countries from 1960 to 1990. We identified prostate cancer cases diagnosed from 1961 to 2005 by linkage of census information to national cancer registries and calculated standardised incidence ratios (SIRs) separately for men aged 30-49 and those aged 50 or older. We also conducted separate analyses by period of follow-up, 1961-1985 and 1986-2005, corresponding to pre- and post-prostate-specific antigen (PSA) screening.

RESULTS

For early-onset prostate cancer (n = 1521), we observed the highest SIRs for public safety workers (e.g. firefighters) (SIR = 1.71, 95% confidence interval [CI]: 1.23-2.31) and military personnel (SIR = 1.97, 95% CI: 1.31-2.85). These SIRs were significantly higher than the SIRs for later-onset disease (for public safety workers, SIR = 1.10, 95% CI: 1.07-1.14 and for military personnel, SIR = 1.09, 95% CI: 1.05-1.13; pheterogeneity = 0.005 and 0.002, respectively). Administrators and technical workers also demonstrated significantly increased risks for early-onset prostate cancer, but the SIRs did not differ from those of later-onset disease (pheterogeneity >0.05). While our early-onset finding for public safety workers was restricted to the post-PSA period, that for military personnel was restricted to the pre-PSA period.

CONCLUSION

Our results suggest that occupational exposures, particularly for military personnel, may be associated with early-onset prostate cancer. Further evaluation is needed to explain these findings.

Costs of productivity loss due to occupational cancer in Canada: estimation using claims data from Workers' Compensation Boards

INTRODUCTION

Cancer is a leading cause of illness globally, yet our understanding of the financial implications of cancer caused by working conditions and environments is limited. The goal of this study is to estimate the costs of productivity losses due to occupational cancer in Canada, and to evaluate the factors associated with these costs.

METHODS

Two sources of data are used: (i) Individual level administrative claims data from the Workers Compensation Board of Nova Scotia; and (ii) provincial aggregated cancer claims statistics from the Association of Workers Compensation Boards of Canada. Benefits paid to claimants are based on actuarial estimates of wage-loss, but do not include medical costs that are covered by the Canadian publicly funded healthcare system. Regional claims level data are used to estimate the total and average (per claim) cost of occupational cancer to the insurance system, and to assess which characteristics of the claim/claimant influence costs. Cost estimates from one region are weighted using regional multipliers to adjust for system differences between regions, and extrapolated to estimate national costs of occupational cancer.

RESULTS/DISCUSSION

We estimate that the total cost of occupational cancer to the Workers' Compensation system in Canada between 1996 and 2013 was $1.2 billion. The average annual cost was $68 million. The cancer being identified as asbestos related were significantly positively associated with costs, whereas the age of the claimant was significantly negatively associated with costs. The industry type/region, injury type or part of body affected by cancer were not significant cost determinants.

CONCLUSION

Given the severity of the cancer burden, it is important to understand the financial implications of the disease on workers. Our study shows that productivity losses associated with cancer in the workplace are not negligible, particularly for workers exposed to asbestos.

Expression patterns of microRNA-329 and its clinical performance in diagnosis and prognosis of breast cancer

This study was aimed to assess the expression and clinical performance of microRNA-329 (miR-329) in breast cancer. We recruited 134 breast cancer patients and 70 healthy volunteers for this study. MiR-329 expression was estimated by quantitative real-time polymerase chain reaction. A receiver operating characteristic assay was performed to evaluate the diagnostic value of serum miR-329. In addition, the prognostic significance of miR-329 was evaluated through Kaplan–Meier survival and Cox regression analyses. According to quantitative real-time polymerase chain reaction, miR-329 expression was downregulated in cancerous samples compared with healthy and normal controls (P<0.01), and its expression in serum specimens positively correlated with its expression in tissue samples (R=0.493, P<0.001). The decreased expression of miR-329 correlated with lymph node metastasis (P=0.015) and TNM stage (P=0.003). A receiver operating characteristic curve with an area under the curve of 0.932 was constructed, indicating the high diagnostic accuracy of miR-329. From the survival and multivariate Cox assays, we found that downregulated miR-329 expression was associated with poor overall survival (log-rank P<0.001) and served as an independent prognostic factor (hazard ratio =2.987, 95% CI =1.681–5.308, and P<0.001). In silico analysis using The Cancer Genome Atlas confirmed that miR-329 expression was lower in breast cancer cases compared with normal controls (P<0.001) and could be an efficient biomarker for cancer patients. Down-regulated miR-329 expression was an effective diagnostic and prognostic biomarker, which could be used for targeted therapy in patients with breast cancer.

Factors associated with the high prevalence of oesophageal cancer in Western Kenya: a review

Oesophageal carcinoma (OC) is highly prevalent in Western Kenya especially among the members of the Kalenjin community who reside in the Northern and Southern areas of the Rift Valley. Previous authors have suggested potential association of environmental and genetic risk factors with this high prevalence. The environmental factors that have been suggested include contamination of food by mycotoxins and/or pesticides, consumption of traditional alcohol (locally referred to “Busaa” and “Chan’gaa”), use of fermented milk (“Mursik”), poor diet, tobacco use and genetic predisposition. The aim of this paper is to critically examine the potential contribution of each of the factors that have been postulated to be associated with the high prevalence of the disease in order to establish the most likely cause. We have done this by analyzing the trends, characteristics and behaviours that are specifically unique in the region, and corroborated this with the available literature.

From our findings, the most plausible cause of the high incidence of OC among the Kalenjin community is mycotoxins, particularly fumonisins from the food chain resulting from poor handling of cereals; particularly maize combined with traditional alcohol laced with the toxins interacting synergistically with other high-risk factors such as dietary deficiencies associated alcoholism and viral infections, especially HPV. Urgent mitigating strategies should be developed in order to minimize the levels of mycotoxins in the food chain.

Analysis of individuals with leukemia: cancer surveillance system limitations

Cancer is the second leading cause of death in the world with great impact on public health and leukemia is a hematological cancer directly related to different exposures at work. This study aimed to describe the occupational profile of individuals diagnosed with leukemia. This is a cross-sectional study of cases registered between 2007 and 2011 in the Integrador RHC database. Individuals from 26 Brazilian states, aged 20 years or older, were included. Of the 7,807 cases of leukemia, Minas Gerais recorded the highest occurrence (1,351). Only 52% of the cases had information on occupation. Occupations with the greatest number of cases of leukemia were agricultural, forestry and fishing workers; services, stores and markets vendors; and workers in the production of industrial goods and services. These occupations are exposed to substances considered by literature as carcinogenic agents to humans. There was a high underreporting of occupational data, compromising the quality of information and, therefore, the effectiveness of the Brazilian health surveillance system. The RHC also does not provide information about the agent used during the working day, the exposure time during working life and data from previous occupations.

Detection of monoclonal B cells in general population from two different regions of Mexico

To estimate the frequency of monoclonal B cells in Mexican general population from two different regions of Mexico. Monoclonal B cells were detected by rearrangements of the immunoglobulin heavy chains (IGH) in 288 individuals: 188 from a metropolitan area and 100 from a rural area. After DNA extraction from peripheral blood by the CTAB/DTAB method, multiplex PCR was used to amplify the IGH rearrangements, followed by capillary electrophoresis. In together, 9.4% of the studied individuals showed monoclonal B cells. This prevalence is significantly higher to those previously described for other populations, but similar to a report in the Spanish population. Among people from the metropolitan area, 12.8% exhibited monoclonal B cells in comparison with 3% of people from the rural area. All individuals showing monoclonal B cells were elder than 40 years. Higher frequency of incomplete monoclonal rearrangements was observed. Individuals from urban areas show significantly increased frequencies of monoclonal B cells regarding the people from the rural area. It is reasonable to believe that the environmental factor could have a greater impact on the development of monoclonality than the genetic component.

Personal use of hair dyes and risk of leukemia: a systematic literature review and meta-analysis

The objective of this study was to examine the association between personal use of hair dyes and the risk of leukemia. We conducted a systematic literature review of epidemiology studies reporting leukemia‐specific cancer risks among hair dye users, and estimated the meta‐relative risk (meta‐RR) and corresponding 95% confidence interval (95% CI) of leukemia, comparing hair dye users to nonusers. When data from all 20 studies that met the inclusion criteria were combined, ever use of hair dye was associated with a nonstatistically significant increased risk of leukemia, meta‐RR = 1.09 (95% CI: 0.97–1.22). When restricted to studies that adjusted for smoking, ever use of hair dye was not associated with leukemia, meta‐RR = 0.99 (95% CI: 0.76–1.29). A statistically significant increased risk of leukemia was associated with permanent hair dye use (meta‐RR = 1.19 [95% CI: 1.07–1.33]), dark hair dye use (meta‐RR = 1.29 [95% CI: 1.11–1.50]), hair dye use among males (meta‐RR = 1.42 [95% CI: 1.01–2.00]), hair dye use pre‐1980 (meta‐RR = 1.49 [95% CI: 1.21–1.83]), and hair dye use for ≥15 years (meta‐RR = 1.35 [95% CI: 1.13–1.62]). Overall, findings suggest that ever use of hair dye is not a significant risk factor for leukemia. Certain hair dye use characteristics were associated with a statistically significant increased risk, but further research is required to determine whether these associations truly reflect a risk of leukemia due to methodological limitations in the underlying studies.

Repeated measures of urinary polycyclic aromatic hydrocarbon metabolites in relation to altered reproductive hormones: A cross-sectional study in China

BACKGROUND

Polycyclic aromatic hydrocarbons (PAHs) are a group of ubiquitous environmental pollutants. In vivo and in vitro studies have demonstrated that PAHs can alter endocrine function, yet evidence from human studies is limited.

OBJECTIVES

The objective of this study was to investigate whether environmental exposure to PAHs was associated with altered reproductive hormone levels, using repeated measures of urinary OH-PAHs as biomarkers.

METHODS

We measured 10 monohydroxylated PAHs (OH-PAHs) in repeated urine samples from 371 men in an infertility clinic in Wuhan, China. Multivariable linear regression models were used to estimate the associations between average urinary OH-PAH levels and serum reproductive hormones, and restricted cubic spline models were further used to examine the shapes of dose-response relationships.

RESULTS

We observed dose-response associations of urinary 2-hydroxynaphthalene (2-OHNa) with decreased serum free testosterone (fT) and urinary 1-hydroxypyrene (1-OHP), 9-hydroxyphenanthrene (9-OHPh), and 9-hydroxyfluorene (9-OHFlu) with decreased serum estradiol (all P for trends <0.05). These associations were linear and significant when these four OH-PAHs were modeled as continuous variables in restricted cubic spline models. Furthermore, a U-shaped association was observed across urinary 4-OHPh levels, with lower levels of serum sex hormone-binding globulin (SHBG) at median concentrations compared with 5th and 95th percentile concentrations.

CONCLUSION

Environmental levels of PAH exposure in our study are associated with altered reproductive hormones. However, further research is needed to confirm our findings.

County-level cumulative environmental quality associated with cancer incidence

BACKGROUND

Individual environmental exposures are associated with cancer development; however, environmental exposures occur simultaneously. The Environmental Quality Index (EQI) is a county-level measure of cumulative environmental exposures that occur in 5 domains.

METHODS

The EQI was linked to county-level annual age-adjusted cancer incidence rates from the Surveillance, Epidemiology, and End Results (SEER) Program state cancer profiles. All-site cancer and the top 3 site-specific cancers for male and female subjects were considered. Incident rate differences (IRDs; annual rate difference per 100,000 persons) and 95% confidence intervals (CIs) were estimated using fixed-slope, random intercept multilevel linear regression models. Associations were assessed with domain-specific indices and analyses were stratified by rural/urban status.

RESULTS

Comparing the highest quintile/poorest environmental quality with the lowest quintile/best environmental quality for overall EQI, all-site county-level cancer incidence rate was positively associated with poor environmental quality overall (IRD, 38.55; 95% CI, 29.57-47.53) and for male (IRD, 32.60; 95% CI, 16.28-48.91) and female (IRD, 30.34; 95% CI, 20.47-40.21) subjects, indicating a potential increase in cancer incidence with decreasing environmental quality. Rural/urban stratified models demonstrated positive associations comparing the highest with the lowest quintiles for all strata, except the thinly populated/rural stratum and in the metropolitan/urbanized stratum. Prostate and breast cancer demonstrated the strongest positive associations with poor environmental quality.

CONCLUSION

We observed strong positive associations between the EQI and all-site cancer incidence rates, and associations differed by rural/urban status and environmental domain. Research focusing on single environmental exposures in cancer development may not address the broader environmental context in which cancers develop, and future research should address cumulative environmental exposures. Cancer 2017;123:2901-8. © 2017 American Cancer Society.

Nonrespiratory mortality and cancer incidence in a cohort of Canadian nickel workers

Mortality and cancer incidence were examined for an updated cohort of nonsinter nickel workers in Sudbury and Port Colborne, Ontario, Canada. Abstract results are provided for those with ≥ 15 years since first exposure. For circulatory disease mortality, significant elevations were observed overall in many Sudbury work areas and in Port Colborne staff. Underground miners, with first exposure before 1960, displayed significant elevations for pneumoconiosis, as well as silicosis and anthrasilicosis, likely due to crystalline silica. Significant elevations in colorectal cancer incidence were observed in Sudbury underground mining, mining maintenance, and maintenance work areas. Given a case-control study is not practical, the next cohort update should include more detailed occupational exposure assessment, including dust exposure, diesel engine emissions, solvents, various metals, silica, and sulphur dioxide.

Effects of Endocrine-Disrupting Chemicals and Epigenetic Modifications in Ovarian Cancer: A Review

Ovarian cancer (OC) is a relatively fatal female reproductive malignancy. Since the underlying causes are uncertain, it brings us to believe that both genetic and external factors contribute toward development of this lethal disorder. Exposure to endocrine-disrupting chemicals (EDCs) in the form of occupational usage of pesticides, fungicides, herbicides, plasticizers, cosmetics, and so on is potentially carcinogenic and their ability to cause epigenetic modifications has led us to hypothesize that they may play a catalytic role in OC progression. In response to synthetic chemicals, animal models have demonstrated disturbances in the development of ovaries and steroid hormonal levels but in humans, more research is required. The present review is an attempt to address the impact of EDCs on the hormonal system and gene methylation levels that may lead to malfunctioning of the ovaries which may consequently develop in the form of cancer. It can be concluded that endocrine disruptors do have a potential carcinogenicity and their high proportions in human body may cause epigenetic modifications, prompting ovarian surface epithelium to grow in an abnormal manner.

County-level cumulative environmental quality associated with cancer incidence

BACKGROUND

Individual environmental exposures are associated with cancer development; however, environmental exposures occur simultaneously. The Environmental Quality Index (EQI) is a county-level measure of cumulative environmental exposures that occur in 5 domains.

METHODS

The EQI was linked to county-level annual age-adjusted cancer incidence rates from the Surveillance, Epidemiology, and End Results (SEER) Program state cancer profiles. All-site cancer and the top 3 site-specific cancers for male and female subjects were considered. Incident rate differences (IRDs; annual rate difference per 100,000 persons) and 95% confidence intervals (CIs) were estimated using fixed-slope, random intercept multilevel linear regression models. Associations were assessed with domain-specific indices and analyses were stratified by rural/urban status.

RESULTS

Comparing the highest quintile/poorest environmental quality with the lowest quintile/best environmental quality for overall EQI, all-site county-level cancer incidence rate was positively associated with poor environmental quality overall (IRD, 38.55; 95% CI, 29.57-47.53) and for male (IRD, 32.60; 95% CI, 16.28-48.91) and female (IRD, 30.34; 95% CI, 20.47-40.21) subjects, indicating a potential increase in cancer incidence with decreasing environmental quality. Rural/urban stratified models demonstrated positive associations comparing the highest with the lowest quintiles for all strata, except the thinly populated/rural stratum and in the metropolitan/urbanized stratum. Prostate and breast cancer demonstrated the strongest positive associations with poor environmental quality.

CONCLUSION

We observed strong positive associations between the EQI and all-site cancer incidence rates, and associations differed by rural/urban status and environmental domain. Research focusing on single environmental exposures in cancer development may not address the broader environmental context in which cancers develop, and future research should address cumulative environmental exposures. Cancer 2017;123:2901-8. © 2017 American Cancer Society.

Assessment of urothelial cells atypical changes among petroleum station workers in Saudi Arabia

The aim of the present study was to assess atypical changes in urothelial cells among petroleum station workers. This is a case control study, investigating 300 participants by cytological methods. Of the 300 participants, 150 were cases (exposed to petroleum products) and 150 were controls (non-exposed). Full voided urine was obtained and was cytologically assessed. Cytological atypia was identified in nine (6%) out of the 150 cases and could not be identified in 141/150 (94%) of the cases, whereas, in the control group, cytological atypia was recognized in four (2.7%) of the 150 controls and could not be identified in 146/150 (97.3%). The risk associated with petroleum product exposure, the odds ratio (OR), and 95% confidence interval (CI) was 2.33 (0.7015–7.7378), P = 0.1673. Exposure of petroleum station workers to petroleum products increases the risk of urothelial atypical changes, which may progress to precancerous and cancerous changes.

New insights on 'old' toxicants in occupational toxicology (Review)

In order to deliver the best possible working environment, it is essential to identify professional conditions that could be harmful for worker's health and prevent (or limit) the occurrence of such conditions. The appropriate use of personal protective equipment and the development of appropriate regulations allowed to reduce the prevalence of 'classic' occupational diseases, such as occupational hearing loss or asbestosis, just to name a few. Nowadays, environmental pollution seems to be one of the most relevant concerns for human and animal health, and toxicology is becoming one of the most prominent fields of interest in occupational settings. An increasing number of studies demonstrate that the presence of toxicants in the workplace could be responsible for the development of chronic diseases, even at doses that were considered 'safe'. The present review summarizes some of the most recent advancements in occupational toxicology, focusing on topics that have long been debated in the past and that have recently returned to the fore.

The increasing toll of adolescent cancer incidence in the US

Cancer incidence is rising among adolescents (“teens”). The causes of the increase are unknown but studying incidence patterns and trends may produce insights into etiology. Using data from the US National Cancer Institute’s Surveillance, Epidemiology, and End Results (SEER) program we described trends of cancer incidence among teens (15–19 year olds). We reviewed and summarized incidence patterns for histologic cancer groups and the most frequently diagnosed sites of cancer among teens during 2008–2012 reported by the SEER Cancer Statistics Review. We calculated annual incidence rates for the years 1975–2012 and used linear regression analysis to evaluate trends and calculate rates of change. Incidence for all sites combined increased annually by 0.67% for males and 0.62% for females during the period 1975 through 2012 –resulting in more than a 25% increase over 38 years. The biggest annual incidence increases occurred in non-Hodgkin lymphoma (NHL) (2.16% females; 1.38% males), thyroid cancer (2.12% females; 1.59% males), acute myeloid leukemia (AML) (1.73% females) and testicular cancer (1.55% males). Incidence rates for most histologic groups and sites showed steady long term increases over the 38 years of data. Despite improvements in survival, rising incidence trends mean growing numbers of young adults are undergoing painful and costly cancer treatments. A concerted research program is vital to investigate causes of steadily rising teen cancer rates.

Urinary Polycyclic Aromatic Hydrocarbon Metabolites and Human Semen Quality in China

Toxicological studies have demonstrated that polycyclic aromatic hydrocarbons (PAHs) exposure impairs male reproductive health. However, the epidemiological evidence is limited and discordant. Our goal was to investigate the relationship between PAH exposures and human semen quality. We analyzed 12 urinary metabolites of PAHs from 933 men who sought semen quality analysis in an infertility clinic in Wuhan, China. Associations with semen quality were assessed using a multivariable linear regression. Restricted cubic splines were used to explore the dose-response relationships between urinary metabolites of PAHs and semen quality. We observed inverse associations between urinary 1-hydroxynaphthalene (1-OHNa) and sperm count, sperm concentration, and percentage of normal morphology (all p for trends <0.05) as well as between urinary ∑OHNa (sum of 1-OHNa and 2-OHNa) and sperm concentration (p for trend =0.04). Additionally, we found inverse associations between urinary 9-hydroxyphenanthrene (9-OHPh) and semen volume and sperm straight-line velocity (both p for trends <0.05) as well as between urinary ∑OHPh (sum of 1-, 2-, 3-, 4-, and 9-OHPh) and sperm count (p for trend =0.04). These dose-response relationships were further confirmed in the curves of the restricted cubic splines. Our data suggest that exposure to naphthalene and phenanthrene is related to decreased semen quality. Our results contribute to the growing body of evidence regarding the widespread exposure to PAHs and the detriment to male reproductive function.

Occupational exposure to pesticides as a possible risk factor for the development of chronic diseases in humans (Review)

It is well known that pesticides are widely used compounds. In fact, their use in agriculture, forestry, fishery and the food industry has granted a huge improvement in terms of productive efficiency. However, a great number of epidemiological surveys have demonstrated that these toxic compounds can interact and exert negative effects not only with their targets (pests, herbs and fungi), but also with the rest of the environment, including humans. This is particularly relevant in the case of workers involved in the production, transportation, preparation and application of these toxicants. Accordingly, a growing body of evidence has demonstrated the correlation between occupational exposure to pesticides and the development of a wide spectrum of pathologies, ranging from eczema to neurological diseases and cancer. Pesticide exposure is often quite difficult to establish, as many currently used modules do not take into account all of the many variables that can occur in a diverse environment, such as the agricultural sector, and the assessment of the real risk for every single worker is problematic. Indeed, the use of personal protection equipment is necessary while handling these toxic compounds, but education of workers can be even more important: personal contamination with pesticides may occur even in apparently harmless situations. This review summarises the most recent findings describing the association between pesticide occupational exposure and the development of chronic diseases.

Occupational exposure to carcinogens: Benzene, pesticides and fibers (Review)

It is well known that the occupational exposure to contaminants and carcinogens leads to the development of cancer in exposed workers. In the 18th century, Percivall Pott was the first to hypothesize that chronic exposure to dust in the London chimney sweeps was associated with an increased risk of developing cancer. Subsequently a growing body of evidence indicated that other physical factors were also responsible for oncogenic mutations. Over the past decades, many carcinogens have been found in the occupational environment and their presence is often associated with an increased incidence of cancer. Occupational exposure involves several factors and the association between carcinogens, occupational exposure and cancer is still unclear. Only a fraction of factors is recognized as occupational carcinogens and for each factor, there is an increased risk of cancer development associated with a specific work activity. According to the International Agency for Research on Cancer (IARC), the majority of carcinogens are classified as 'probable' and 'possible' human carcinogens, while, direct evidence of carcinogenicity is provided in epidemiological and experimental studies. In the present review, exposures to benzene, pesticides and mineral fibers are discussed as the most important cancer risk factors during work activities.

Pesticide exposure and risk of bladder cancer: A meta-analysis

OBJECTIVE

We conducted a meta-analysis to quantitatively evaluate the correlation between pesticide exposure and the risk of bladder cancer by summarizing the results of published case-control and cohort studies.

METHODS

A systematic literature search of articles update to February 2015 was conducted via Pubmed, Web of Science, Cochrane Library, and the Chinese National Knowledge Infrastructure (CNKI) databases, and the references of the retrieved articles. Fixed- or random-effect models were used to summarize the estimates of OR with 95% CIs for the highest versus the lowest exposure of pesticide.

RESULTS

The pooled OR estimates indicated that pesticide exposure was associated with an increased risk of bladder cancer (OR=1.649, 95% CI 1.223-2.223). In subgroup analysis, we detected pesticide exposure demonstrated as a significant risk factor on bladder cancer in America (OR=1.741, 95% CI 1.270-2.388). Similar results were discovered in both case-control group and cohort group (OR=2.075, 95% CI 1.183-3.638, OR=1.146, 95% CI 1.074-1.223, respectively). No evidence of publication bias was found by Begg's or Egger's test (P = 0.210, P = 0.358, respectively).

CONCLUSION

In conclusion, our meta-analysis indicated that pesticide exposure was associated with an increased risk of bladder cancer. Further researches should be conducted to confirm the findings in our study and better clarify the potential biological mechanisms.

Potential breast cancer risk factors among Saudi women aged 19-50 years in Jeddah: a case-control study

BACKGROUND AND OBJECTIVES

The Saudi cancer registry reported in 2009 that the frequency of breast cancer is the highest among all types of cancer among Saudi women aged 30-59 years. The Makkah region had the second highest frequency of reported breast cancer cases, with patients having a median age of 46 years. The objectives of this study were to explore the distribution of selected known and hypothetically claimed breast cancer risk factors among Saudi women aged 19-50 years and describe the association of breast cancer with selected risk factors.

DESIGN AND SETTING

An unmatched case-control study was conducted on breast cancer cases at three different hospitals in Jeddah.

PATIENTS AND METHODS

Online OpenEpi was used and the method of Kelsey and colleagues was selected from OpenEpi output; the calculated number of cases and controls was 134 each. Women aged 19-50 years were included and the analysis was conducted on 151 cases and 166 controls as they met the age inclusion criteria.

RESULTS

The mean age of patients was 40 years. A subgroup analysis for age at menarche less than 12 years showed an odds ratio (OR) of 1.4 6 [95% confidence interval (CI) 0.88-2.44]. A high proportion of cases reported the use of exogenous estrogen and progesterone (OR=4.7, 95% CI 1.7-13.0), previous mammography screening (89% of cases vs. 11% of controls), and affected family members (4.6 vs. 1.8, OR=2.64 [95% CI 0.67-10.4]. The OR for exercise frequency in the study group was 1.45 (95% CI 0.90-2.35). The OR for breastfeeding among mothers who breast-fed for more than 12 months was 0.56 (95% CI 0.35-0.88).

CONCLUSION AND RECOMMENDATIONS

This study provides information on associative factors such as early age at menarche (<12 years), monthly income of at least 20 000 SR (5333 USD), use of exogenous estrogen and progesterone, previous biopsies/surgeries, previous clinical breast examination and mammography screening, and affected family members. Protective factors among premenopausal women, such as breastfeeding and exercising, have been described. Conducting comprehensive sessions on breastfeeding and physical education targeting young generations is highly recommended in order to reduce the risk for breast cancer among Saudi women aged 19-50 years.

Epidemiologic, Racial and Healthographic Mapping of Delaware Pediatric Cancer: 2004-2014

Childhood cancer remains the leading cause of disease-related death among children 0 to 14 years and incidence varies by race, ethnicity, sex, geographic locale, and age at onset. However, data are unavailable in some regions, indicative of a need for such information for cancer awareness, education and prevention program. We utilized retrospective epidemiologic design to assess and characterize pediatric tumors in the Nemours Electronic Medical Records, between 2004 and 2014. Tumor frequency and children population size were used to determine the period prevalence as cumulative incidence (CI) proportion, as well as chi-square and Poisson Regression. The CI for overall childhood cancer in Delaware was 234 per 100,000 children, and varied by race, black (273 per 100,000), white (189 per 100,000). Similarly, sex variability was observed in CI, boys (237 per 100,000) and girls (230 per 100,000). The most commonly diagnosed malignancies were acute lymphoblastic leukemia (ALL), Central Nervous System (CNS)/brain and renal cancer. The geographic locales with relatively higher cancer CI in the state of DE were zip codes 19804 and 19960, but this does not imply cancer clustering. Differences in overall childhood cancer distribution occurred by race, sex, geography, and age. These findings are indicative of the need for cancer-specific health education, awareness and prevention programs in reducing the observed disparities in Delaware.

Genetic Polymorphism, Telomere Biology and Non-Small Lung Cancer Risk

Recent genome-wide association studies (GWAS) have identified a number of chromosomal regions associated with the risk of lung cancer. Of these regions, single-nucleotide polymorphisms (SNPs), especially rs2736100 located in the telomerase reverse transcriptase (TERT) gene show unique and significant association with non-small cell lung cancer (NSCLC) in a few subpopulations including women, nonsmokers, East Asians and those with adenocarcinoma. Recent studies have also linked rs2736100 with a longer telomere length and lung cancer risk. In this review, we seek to summarize the relationship between these factors and to further link the underlying telomere biology to lung cancer etiology. We conclude that genetic alleles combined with environmental (e.g., less-smoking) and physiological factors (gender and age) that confer longer telomere length are strong risk factors for NSCLC. This linkage may be particularly relevant in lung adenocarcinoma driven by epidermal growth factor receptor (EGFR) mutations, as these mutations have also been strongly linked to female gender, less-smoking history, adenocarcinoma histology and East Asian ethnicity. By establishing this connection, a strong argument is made for further investigating of the involvement of these entities during the tumorigenesis of NSCLC.

Time-resolved fluorescence sensing of pesticides chlorpyrifos, crotoxyphos and endosulfan by the luminescent Eu(III)-8-allyl-3-carboxycoumarin probe

This work describes the application of time resolved fluorescence in microtiter plates for investigating the interactions of europium-allyl-3-carboxycoumarin with pesticides chlorpyrifos, endosulfan and crotoxyphos. Stern-Volmer studies at different temperatures for chlorpyrifos and crotoxyphos shows dynamic and static quenching mechanisms respectively. Direct methods for the determination of the pesticides under investigation have been developed using the luminescence variations of the probe in solution. The detection limits are 6.53, 0.004, 3.72 μmol/L for chlorpyrifos, endosulfan, and crotoxyphos, respectively. The binding constants and thermodynamic parameters of the pesticides with probe were evaluated. A thermodynamic analysis showed that the reaction is spontaneous with negative ΔG. Effect of some relevant interferents on the detection of pesticides has been investigated. The new method was applied to the determination of the pesticides in different types of water samples (tap, mineral, and waste water).

Exposure to ambient air pollution in Canada and the risk of adult leukemia

There is a paucity of studies investigating adult leukemia and air pollution. To address this gap, we analyzed data from a Canadian population-based case-control study conducted in 1994-1997. Cases were 1064 adults with incident leukemia and controls were 5039 healthy adults. We used data from satellites and fixed-site monitoring stations to estimate residential concentrations of NO2 and fine particulate matter (PM2.5) for the period prior to diagnosis, starting in 1975 and ending in 1994. We modeled the average annual exposure of each subject. Odds ratios (OR) and their 95% confidence intervals (CI) were estimated using logistic regression, adjusted for age, gender, province, smoking, education, body mass index, income, and self-reported exposures to ionizing radiation and benzene. We found an 'n-shaped' response function between exposure to NO2 and all forms of leukemia: from the tenth percentile to the median (4.51 to 14.66 ppb), the OR was 1.20; 95% CI: 0.97-1.48 and from the 75th percentile to the 90th (22.75 to 29.7 ppb), the OR was 0.79; 95% CI 0.68-0.93. For PM2.5 we found a response function consistent with a linear model, with an OR per 10 μg/m(3) of 0.97 (95% CI 0.75-1.26). For chronic lymphocytic leukemia we found response functions that were consistent with a simple linear model, with an OR per 5 ppb of NO2 of 0.93 (95% CI 0.86-1.00) and an OR per 10 μg/m(3) of PM2.5 of 0.62 (95% CI 0.42-0.93). In summary, for chronic lymphocytic leukemia we found no evidence of an association with air pollution and with all forms of leukemia we found weak evidence of an association only at low concentrations of NO2. It is possible that these inconsistent results may have arisen because of unaccounted urban/rural differences or possibly from a selection effect, especially among controls.