The effect of age on the relative risk of lung cancer mortality in a cohort of chromium production workers

Background

Hexavalent chromium has been found to increase the risk of lung cancer in occupational studies. It has been suggested that the relative risk of lung cancer may vary by age.

Methods

The cohort examined is the Baltimore cohort of chromium production workers. The effect of age on the lung cancer risk from hexavalent chromium exposure was examined using a conditional Poisson regression modeling approach of Richardson and Langholz (R&L) and Cox models with interaction terms of age and cumulative hexavalent chromium exposure.

Results

The inclusion of multiple age groups in the R&L approach suggests the existence of an age effect that is also supported by a Cox proportional hazard analysis. The hazard ratio in Cox models with age‐cumulative exposure interaction terms was significantly elevated for the youngest age group and significantly decreased for the oldest age group.

Conclusions

Our analyses are consistent with the observation that younger chromium production workers have a greater lung cancer risk than older workers.

Estimates of the 2015 global and regional disease burden from four foodborne metals - arsenic, cadmium, lead and methylmercury

The impact of foodborne metals on the burden of disease has been largely overlooked, in comparison to the attention on acute diseases associated with infectious foodborne agents. Four articles in this special section describe in detail the burden of disease from foodborne lead, methylmercury, arsenic, and cadmium. Ingested lead and methylmercury are causally associated with lifelong intellectual disability. Long term ingestion of arsenic is causally associated with an increased risk of cancer. Long term ingestion of cadmium is causally associated with an increased risk of late stage chronic kidney disease. This article presents an overview of the burden of disease from these four foodborne metals and discusses them in the context of the World Health Organization's initiative to estimate the global burden of foodborne disease. The results indicate that in 2015, ingestion of arsenic, methylmercury, lead, and cadmium resulted in more than 1 million illnesses, over 56,000 deaths, and more than 9 million disability-adjusted life years (DALYs) worldwide. The greatest impact on DALYs was in the Western Pacific B subregion. All of the metals were found to have high DALYs per case in comparison with other foodborne disease agents, including infectious and parasitic agents. In addition, lead, arsenic, and methylmercury were found to have high DALYs per 100,000 population in comparison to other foodborne disease agents.

Global burden of intellectual disability resulting from prenatal exposure to methylmercury, 2015

We describe analyses to estimate the global burden of disease associated with methylmercury (MeHg). An intelligence quotient < 70, indicating intellectual disability (ID), was selected as the critical disease, maternal hair Hg concentration during pregnancy selected as the critical exposure biomarker, and a dose-effect relationship of an 0.18 point IQ reduction per µg/g increase in maternal hair Hg was assumed, based on a meta-analysis. A systematic review was conducted to obtain country-specific data on the distribution of maternal hair Hg concentrations. The country-specific incidence of MeHg-associated ID was calculated, and a random effects model was used to impute the incidence for countries for which no exposure data could be found. The global burden of MeHg-associated ID was quantified in terms of Disability-Adjusted Life Years (DALYs) using the World Health Organization (WHO) Global Health Estimates methodology, and presented by 14 subregions. In 2015, the global total for MeHg-associated cases of ID was 226,655; 210,074 of these cases (93%) were mild cases of ID. The highest rate of ID (6 cases per 100,000 population) was found in the Americas D subregion. The global DALY estimate was 1,963,869. The Western Pacific B subregion contributed the most to this total (696,417), although the Americas D subregion had the greatest rate (54 DALYs per 100,000 population). The burden of disease associated with MeHg is therefore highly subregion-dependent even in areas that are geographically related. The priority given to reducing this burden can therefore be expected to vary considerably by subregion depending on other health needs.

The internet as a source of support for youth with chronic conditions: A qualitative study

BACKGROUND

Adolescents living with chronic conditions often portray themselves as "healthy" online, yet use the Internet as one of their top sources of health information and social communication. There is a need to develop online support programs specific to adolescents with chronic conditions in order to provide a private space to discuss concerns. This paper endeavors to increase our understanding of the online support needs and wants of these adolescents and their interest in and preferences for an online support program.

METHODS

A qualitative descriptive study using semistructured interviews was completed. Stratified purposive sampling was utilized to ensure a representative sample based on age and diagnosis. English speaking adolescents (aged 12-18 years) diagnosed with a chronic condition were recruited from clinic and inpatient areas across 3 paediatric hospitals in Canada.

RESULTS

Thirty-three participants aged 15.3 ± 1.8 years (64% female) completed the study. The main topics identified were (a) the purpose of current online activity, (b) the benefits and challenges of existing online supports, and (c) a description of ideal online resources. The purpose of online activity was social networking, information, online gaming, and social support. When accessing health information online, participants prioritized websites that were easy to access and understand despite the trustworthiness of the site. The reported benefits and challenges varied across participants with many areas perceived as both a benefit and a challenge. The majority of participants were interested in participating in an online support program that included both accurate disease-related information and a community of other adolescents to provide social support.

CONCLUSIONS

Adolescents with chronic conditions are interested in online support that encompasses health information and social support that is flexible and easy to navigate. Findings can be used to develop or adapt existing online support programs for adolescents with chronic conditions to help increase engagement and utilization.

Country-specific estimates of the incidence of intellectual disability associated with prenatal exposure to methylmercury

This paper describes country-specific estimates of the incidence of intellectual disability in children associated with prenatal exposure to methylmercury. A systematic review was undertaken to identify country-specific data on hair mercury concentrations in women of reproductive age. A variety of approaches were used to estimate biomarker concentrations for countries lacking such data. A dose-effect relationship derived on the basis of the data from three large prospective studies relating prenatal methylmercury exposure to IQ in children was used to estimate the country-specific incidences of mild, moderate, severe, and profound intellectual disability in children as a result of prenatal methylmercury exposure. The incidence of methylmercury-associated mild intellectual disability (IQ scores 50-70) varied nearly 40-fold across countries, with the greatest incidences generally in countries that are islands or that are coastal. Countries with high birth rates and greater consumption of foods that contribute most to methylmercury intake in humans (seafood, rice) can be expected to make the largest contributions to the worldwide burden of disease associated with methylmercury. The assumptions and limitations of the estimates are discussed.

Identification of Endoglin as an epigenetically regulated tumour-suppressor gene in lung cancer

Background:

The transforming growth factor-beta (TGF- β) pathway has been implicated in proliferation, migration and invasion of various cancers. Endoglin is a TGF-β accessory receptor that modulates signalling. We identified Endoglin as an epigenetically silenced tumour-suppressor gene in lung cancer by means of a genome-wide screening approach, then sought to characterise its effect on lung cancer progression.

Methods:

Methylation microarray and RNA sequencing were carried out on lung cancer cell lines. Epigenetic silencing of Endoglin was confirmed by methylation and expression analyses. An expression vector and a 20-gene expression panel were used to evaluate Endoglin function. Pyrosequencing was carried out on two independent cohorts comprising 112 and 202 NSCLC cases, respectively, and the impact of Endoglin methylation on overall survival (OS) was evaluated.

Results:

Methylation in the promoter region resulted in silencing of Endoglin, which could be reactivated by demethylation. Increased invasion coupled with altered EMT marker expression was observed in cell lines with an epithelial-like, but not those with a mesenchymal-like, profile when Endoglin was absent. Methylation was associated with decreased OS in stage I but not in stages II–III disease.

Conclusions:

We show that Endoglin is a common target of epigenetic silencing in lung cancer. We reveal a link between Endoglin silencing and EMT progression that might be associated with decreased survival in stage I disease.

Gestational carrier BMI and reproductive, fetal and neonatal outcomes: are the risks the same with increasing obesity?

OBJECTIVE

Data suggest that female obesity impairs uterine receptivity and increases the risk of fetal and neonatal mortality. We analyzed the reproductive outcomes of gestational carriers (GCs) undergoing donated oocytes and assisted reproductive technology according to body mass index (BMI).

DESIGN

A retrospective analysis of 163 GCs undergoing 226 in vitro fertilization (IVF) and embryo transfer cycles.

METHODS

GCs undergoing in vitro fertilization and embryo transfer cycles were analyzed and divided according to their BMI (healthy weight: 20-24.9 kg m(-2) (n=77 in 114 cycles); overweight: 25-29.9 kg m(-)(2) (n=55 in 71 cycles); and obese: 30-35 kg m(-)(2) (n=31 in 41 cycles)). All GCs underwent a complete medical evaluation and were cleared for pregnancy before being selected. Overweight and obese GCs also underwent a metabolic screening, including an oral glucose tolerance test and lipid profile. The main outcomes measured were clinical pregnancy and live birth rates, antenatal and neonatal outcomes.

RESULTS

Clinical pregnancy and live birth rates were similar despite increasing BMI. There were no statistically significant differences in the implantation rates, clinical pregnancy rates or live birth rates per embryo transfer among patients in the three BMI groups. In the healthy weight, overweight and obese GCs, the clinical pregnancy rates per GC were 72%, 84% and 79%, and per embryo transfer rates were 52%, 49% and 56%, respectively; P=NS. The live birth rates per GC were 70%, 84% and 75%, and per embryo transfer rates were 50%, 49% and 53%, respectively; P=NS. Twin rates were similar between the groups (35%, 31% and 29%, respectively; P=NS). There were no differences in gestational diabetes, preterm admissions or cesarean section rates. Neonatal intensive care unit admissions were similar (11%, 13% and 12%, respectively; P=NS), and no maternal, neonatal or infant mortality occurred.

CONCLUSIONS

These data show that increasing obesity does not impair the reproductive outcome in GC cycles. Larger sample size is indicated to verify these findings. Furthermore, this study suggests that the standard metabolic screening used for GCs may lead to selection of healthier patients compared with women of comparable BMI who conceive outside of a fertility clinic setting, indicating the metabolic profile, rather than BMI, may better explain differences in pregnancy outcomes.

Abstract P2-09-05: The potent anti-androgen enzalutamide demonstrates broad anti-tumour activity across all androgen receptor-positive triple-negative breast cancer subtypes

Background: Up to 30% of triple-negative breast cancers (TNBC) show expression of the androgen receptor (AR) and may therefore be candidates for AR-targeted therapy. Molecular profiling of TNBC has identified the luminal AR (LAR) subset, which shares many aspects of ER-positive luminal cancers but is resistant to ER-targeted therapy. LAR cancers highly express the AR, are heavily enriched in hormone-regulated pathways and demonstrate tumour growth in response to androgen stimulation that can be inhibited by the mixed AR agonist/antagonist bicalutamide. The objective of this study was to investigate the role of AR signalling in TNBC in more detail and to evaluate the potential of the second generation anti-androgen Enzalutamide in this setting relative to bicalutamide.

Methods: A panel of 13 TNBC breast cancer cell lines was selected, representing different molecular subtypes of TNBC (including 4 LAR cell lines). Baseline AR expression was determined using qPCR (Taqman) and Western-Blot (Antibody, Santa Cruz Biotechnology). The effects of enzalutamide and bicalumatide on cell proliferation and survival were determined using MTT assays with and without DHT stimulation. Comprehensive molecular profiling (including Illumina Human HT-12 v4 whole genome mRNA and Illumina Human 450K methylation microarrays) was applied before and after enzalutamide treatment to define the molecular signature associated with sensitivity to enzalutamide therapy. All statistical calculations and IC50 doses were calculated using Prism v6.0 (GraphPad).

Results: A wide range of AR expression was confirmed across the cell line panel defining 3 groups with complete lack of AR expression, low/moderate AR expressions levels, or very high expression in the LAR subtype (with up to 100-fold greater AR expression compared to other TNBC subtypes). Enzalutamide demonstrated broad anti-tumour activity across all AR+ TNBC subtypes (but not in AR-negative subtypes), with IC50 values being similar in LAR and non-LAR cell lines. Treatment with enzalutamide resulted in more effective growth inhibition and a broader range of activity compared to bicalutamide. Data on molecular profiles of enzalutamide sensitivity will be presented at the meeting.

Conclusion: AR inhibition is a promising therapeutic strategy for both LAR and non-LAR AR-expressing TNBC. The potent anti-androgen enzalutamide shows broad activity across all AR+ TNBC subtypes and warrants further clinical evaluation. A phase 2 study of enzalutamide in AR+ TNBC has been initiated.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P2-09-05.

Abstract P4-06-10: Epigenetic silencing of glutamine synthetase (Glul) defines glutamine depletion therapy

Background: Methylation-dependent transcriptional silencing of genes involved in amino acid synthesis can provide potential targets for novel synthetic lethality strategies. Glutamine synthetase (Glul) is the key enzyme in the biosynthesis of glutamine. We identified Glul as a novel gene subject to methylation-dependent transcriptional silencing in breast cancer cell lines using a combined functional screen with methylation reversal assays and methylation arrays.

Methods: Methylation reversal assays were performed using 5-aza-2-deoxycytidine and/or trichostatin treatment coupled with whole genome mRNA microarrays (Illumina HT-12 v4 Expression BeadChip Kit). Expression of Glul with and without pharmacological methylation reversal with azacytidine and/or trichostatin was validated using qRT-PCR and Western Blot. Methylation of Glul was analysed using methylation microarrays (Illumina 450K Methylation BeadChip), bisulphite sequencing and pyrosequencing. Sensitivity to glutamine deprivation was assessed using an MTT assay after culturing cells in media with various glutamine concentrations or in complete absence of glutamine. We used a panel of 55 breast cancer cell lines and formalin-fixed paraffin-embedded tissue from a series of 116 stage I-III primary breast cancers with linked mature clinical outcome data that were randomly selected from the Cuneo Tissue Bank. Tissue samples were subject to histopathological review to ensure adequate representation of cancer cells.

Results: Dense methylation of the CpG-island of Glul was detected in 45% of cell lines across all subtypes. Methylation of the CpG island was linked with absent or down-regulated expression of Glul in some but not all cell lines, and Glul expression could be reactivated by azacytidine and trichostatin in these cell lines. Methylation of shore areas was detected in several cell lines but was not associated with transcriptional silencing. Cells with methylation-dependent low or absent Glul expression were highly sensitive to glutamine deprivation, whereas cell lines without Glul methylation were rescued by compensatory up-regulation of Glul. Using pyrosequencing, dense methylation of the CpG island of Glul was found in 32.8% of patients, with an additional 17.2% of patients showing partial methylation. No significant association with a specific breast cancer subtype or outcome was found.

Conclusions: This is the first report of methylation-dependent transcriptional silencing of Glul expression in cancer. Our data demonstrate that a significant proportion of primary breast cancers show methylation of Glul and suggest that glutamine deprivation could be a novel synthetic lethality strategy for these cancers.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P4-06-10.

Hospital discharge analysis of oncology patients from thirteen acute general hospitals which belong to the City of Buenos Aires Government (CBAG)

21183

Background: Statistical report which considers the discharge of oncology patients from thirteen acute general Hospitals from the CBAG in order to determine how to allocate founds and propose epidemilogy, preventive and/or therapeutics trials. Methods: Review of the information given by the HSD of the CBAG Ministry.The variables taken into account were: type of cancer (CIE-10-OMS), sex, age and area of residency. Results: During 2005, in the 13 acute care hospitals of CBAG there were 132,431 disc; among these 6,896 were oncology patients (5%). From the total number of hospital beds used that year (1,074,495), 90,352 were oncology patients (9%). The malignant tumor diagnosis were; Gynecologic 23% (cervix 689 + in situ 134, ovarian 479, uterine 120 and other 188); digestive 15% (colorectal 529, pancreatic 149, stomach 134, esophagus 188 and others 34); hematologic 15% (lymphomas 500, leukemias 410, myelomas 77 and others 46); breast 12% (849); lung 10% (681); urologic 9% (bladder 228, prostate 187, kidney 115, testicle 43 and others 22); miscellaneus 15% (1,065). Sex: Female (F) discharges were 4,158 and male (M) 2,738; the relationshionship F/M was 1.5/1. The group mean age was 56.1± 16.6 years. Area of residence: 53% belonged to the City of Buenos Aires and 40 % to suburban areas. Conclusions: The diagnosis of the pathologies found could help determine epidemiology and therapeutic trials. Hospitalizacions due to cancers that can be ‘prevented by screening‘, such as breast, cervical and colon cancer, support the need to redefine prevention campaigns.

No significant financial relationships to disclose.

Influence of folic acid-fortified foods on folate status in a folate depletion–repletion rat model

An increasing number of foods fortified with varying levels of folic acid are appearing in the market place, targeted either at the general population or at specific consumer groups. Although it is assumed that the folate in these products should be highly bioavailable, there is a need to carry out studies to ascertain that this is, in fact, the case. The present study investigated the ability of selected folic acid-fortified foods (targeted at different types of consumer) to increase the folate status of folate-deficient rats. Forty-two weanling male rats (Wistar strain) were fed a folate-deficient diet containing 1 % succinyl sulfathiazole (w/w) for 28 d. Following depletion, seven rats were randomly assigned to each of five repletion diets containing folic acid, Complan®, Slim Fast®, Opti-Fuel2®or Cola Coa®calculated to provide 200 μg folate/kg of each diet. Calculations were based on folate information from the product labels. After a further 28 d, plasma, liver and kidney folate concentrations were determined by microbiological assay. Plasma homocysteine was measured by HPLC as a functional indicator of folate status. The folate content of the foods was measured by tri-enzyme extraction followed by microbiological assay. Our analyses suggest that there may be considerable inaccuracies on the part of the manufacturers in relation to the folate declarations on the product labels. Despite this, the four foods evaluated were highly effective in elevating plasma, liver and kidney folate and lowering plasma homocysteine concentrations in rats. These results lend support to the policy of food fortification with folic acid as a means of raising the folate status of the population, and in particular to the fortification of specific foods which may target areas of the population where increased folate status is most needed.

Plasma, liver and kidney folate and plasma homocysteine concentrations are poor response variables at very low dietary folate intakes, in a folate depletion/repletion rat model

Folate depletion/repletion rat models are popular protocols for assessing the bioavailability of folate. Much of the early work carried out on folate bioavailability concentrated on foods naturally high in folate. However, foods low in folate often contribute significantly to folate intake because of their high consumption in the general population. Therefore, the assessment of the bioavailability of foods low in folate is essential to properly estimate folate intake. The present study investigated plasma, liver and kidney folate and plasma homocysteine concentrations as appropriate response variables for measuring folate bioavailability in the rat at very low dietary folate intakes. One hundred and one weanling male rats (Wistar strain) were fed a folate-deficient diet containing 1% succinyl sulfathiazole for 28 d. Following depletion, six rats were randomly assigned to each of 16 repletion diets containing folic acid, fortified white bread, unfortified wholemeal bread or unfortified rye bread calculated to provide 6.25, 12.5, 18.75 and 25 micrograms folate/kg of each diet. After a further 28 d, plasma, liver and kidney folate concentrations were determined by microbiological assay. Plasma homocysteine was measured by HPLC as a functional indicator of folate status. Only a weak correlation was found between the response variables measured and dietary folate intake, indicating that this folate depletion/repletion rat model is not suitable for testing the response of rats fed diets containing very low levels of folate.

Effects of preparation and cooking of folic acid-fortified foods on the availability of folic acid in a folate depletion/repletion rat model

The practice of food fortification with folic acid offers the potential to increase the folate intake of the general population. To fully exploit the potential of fortification for raising folate nutriture, appropriate food vehicles need to be selected. Selection should involve determination of the availability of folic acid as affected by characteristics of the carrier food, food matrix, food preparation, and cooking. The present study investigated the effects of preparation and cooking of a range of folic acid-fortified foods on the folate status of folate-deficient rats. Fifty-six weanling male rats (Wistar strain) were fed a folate-deficient diet containing 1% succinyl sulfathiazole for 28 days. Following depletion, six rats were randomly assigned to each of eight repletion diets containing cooked or uncooked meringue mix, quick bread mix, brownie mix, or pizza base mix. The test foods were fortified with 1400 microg of folic acid/kg of food and incorporated as 19% of the repletion diets. Each of the first four groups was pair-fed a diet containing a cooked fortified food with another group fed the corresponding uncooked fortified food. After a further 28 days, plasma, liver, and kidney folate concentrations were determined by microbiological assay. Mean plasma and liver folate concentrations of rats fed diets containing cooked fortified foods were similar to those of rats fed uncooked fortified foods. Preparation and cooking did not affect the availability of folic acid from the selected cereal-based convenience foods in this rat model system, suggesting that these foods are appropriate vehicles for fortification with folic acid.

Evolution of a state occupational lead exposure registry: 1986-1996

In the first 11 full years of operation (January 1, 1986, through December 31, 1996) of an adult lead registry in New Jersey, 23,456 reports of occupational lead toxicity (blood lead level > or = 1.21 mumol/L) in 4,011 workers, involving 496 workplaces, were received. The majority of the reports and workers were from the manufacturing and construction industries. Over the 11 years, the annual numbers of reports and workers declined, although the annual numbers of involved workplaces remained stable, as did the number of newly identified workers and workplaces. The decline occurred primarily in the manufacturing industry; the construction industry experienced an increase in reports and reported workers. For all years combined, 36% of reported workers had at least one blood lead level equal to or greater than 1.93 mumol/L, although in the most recent years the percentage dropped overall and in both the manufacturing and construction industries.

Occupational asthma caused by himic anhydride

Acid anhydride compounds are reactive chemicals that have been previously associated with immunoglobulin E (IgE) mediated occupational asthma. Twenty workers with exposure to himic anhydride powder used for the manufacture of a synthetic flame retardant were questioned about respiratory symptoms. The study was initiated after one individual from the plant developed asthma. A test for serum-specific IgE to human serum albumin conjugates of himic anhydride, phthalic anhydride, hexahydrophthalic anhydride and trimellitic anhydride was performed for seven workers with respiratory symptoms associated with himic anhydride exposure. Three of the seven symptomatic workers who reported wheezing at work exhibited elevated specific IgE to two or more acid anhydride-human serum albumin conjugates. Radioallergosorbent inhibition studies performed with sera containing high levels of himic anhydride-human serum albumin specific IgE from a symptomatic worker demonstrated cross-allergenicity between himic anhydride-human serum albumin and hexahydrophthalic anhydride-human serum albumin allergenic determinants. This study demonstrated that himic anhydride can elicit IgE-mediated sensitization in the workplace.

Elevated levels of carbon monoxide in the patient compartment of ambulances

Six hundred and ninety New Jersey ambulances were monitored for carbon monoxide (CO); 27 per cent had CO levels of 10 ppm or more greater than ambient air in the breathing zone of the patient. Twenty-nine of these ambulances had levels of at least 35 ppm greater than ambient air. Results indicate that a CO exposure problem exists in ambulances.

Non-invasive magnetopneumographic determination of lung dust loads in steel arc welders

Magnetopneumography was used to measure non-invasively the concentration of the ferrimagnetic fraction of retained welding fume in the thoraces of steel arc welders. This was done by measuring the remanent magnetic fields due to ferrimagnetic particles. The 11 welders studied had concentrations of thoracic ferrimagnetic mineral several orders of magnitude greater than three machinists, 16 former asbestos insulators and 24 control subjects. These concentrations correlated well with total years welding (p less than 0.01) and radiographic evidence of small rounded densities (p less than 0.05), but not with smoking history. There was a higher concentration of ferrimagnetic mineral over the hilar regions. Magnetopneumography offers a non-invasive indicator of the accumulation of welding fume in the thorax.