A meta-analysis of bladder cancer and diesel exhaust exposure

Occupational exposure to diesel exhausts and liver and pancreatic cancers: a systematic review and meta-analysis

BACKGROUND

Diesel exhaust (DE) is human carcinogen with sufficient evidence only for lung cancer. Systematic evidence on other cancer types is scarce, thus we aimed to systematically review current literature on the association between occupational DE exposure and risk of liver and pancreatic cancers.

METHODS

We performed a systematic literature review to identify cohort studies on occupational DE exposure and risk of cancers other than lung. We computed pooled relative risks (RRs) and corresponding 95% confidence intervals (CIs) for liver and pancreatic cancers using DerSimonian and Laird random-effects model.

RESULTS

Fifteen studies reporting results on pancreatic cancer and fourteen on liver cancer were included. We found a weakly increased risk of pancreatic cancer in workers exposed to DE (RR: 1.07, 95% CI: 1.00, 1.14), mainly driven by results on incidence (RR: 1.11, 95% CI: 1.02, 1.22). As for liver cancer, results were suggestive of a positive association (RR: 1.09; 95% CI: 0.99, 1.19), although a significant estimate was present in studies published before 2000 (RR: 1.41; 95% CI: 1.09, 1.82). We found no compelling evidence of publication bias.

CONCLUSIONS

Our findings suggest an association between occupational DE exposure and liver and pancreatic cancer. Further studies with detailed exposure assessment, environmental monitoring data, and appropriate control for confounders are warranted.

Disparity of Bladder Cancer Incidence Among Male Workers Across Industries: A Population Based Cohort Study From South Korea

BACKGROUND

This study aimed to investigate the bladder cancer risk across workers' industries.

METHODS

This study was conducted using Korean National Health Insurance claims data. Workers were included in this study to build a retrospective cohort of the entire working population. Workers' industries were divided into 77 industries according to the Korean Standard Industry Classification division category. The standardized incidence ratio was calculated by comparing 77 industries according to the Korean Standard Industry Classification with the educational public officer.

RESULTS

Bladder cancer risk was particularly high in the following industrial sectors: passenger land transport, except transport via railways; sea and coastal water transport; restaurants and mobile food service activities; telecommunications; and computer programming, consultancy, and related activities.

CONCLUSIONS

Our result provides evidence regarding the disparity of bladder cancer incidence among male workers across industries.

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

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

Diesel Exhaust Exposure and Cause-Specific Mortality in the Diesel Exhaust in Miners Study II (DEMS II) Cohort

BACKGROUND

With the exception of lung cancer, the health effects associated with diesel exhaust for other cancers and nonmalignant health outcomes are not well understood.

OBJECTIVES

We extended the mortality follow-up of the Diesel Exhaust in Miners Study, a cohort study of 12,315 workers, by 18 y (ending 31 December 2015), more than doubling the number of observed deaths to n = 4,887 , to evaluate associations between mortality and diesel exhaust exposure.

METHODS

Quantitative estimates of historical exposure to respirable elemental carbon (REC), a surrogate for diesel exhaust, were created for all jobs, by year and facility, using measurements collected from each mine, as well as historical measurements. Standardized mortality ratios (SMRs) and hazard ratios (HRs) were estimated for the entire cohort and by worker location (surface, underground).

RESULTS

We observed an excess of death for cancers of the lung, trachea, and bronchus (n = 409 ; SMR = 1.24 ; 95% CI: 1.13, 1.37). Among workers who ever worked underground, where the majority of diesel exposure occurred, excess deaths were evident for lung, trachea, and bronchus cancers (n = 266 ; SMR = 1.26 ; 95% CI: 1.11, 1.42). Several nonmalignant diseases were associated with excess mortality among workers ever-employed underground, including ischemic heart disease (SMR = 1.08 ; 95% CI: 1.00, 1.16), cerebrovascular disease (SMR = 1.22 ; 95% CI: 1.04, 1.43), and nonmalignant diseases of the respiratory system (SMR = 1.13 ; 95% CI: 1.01, 1.26). Continuous 15-y lagged cumulative REC exposure < 1,280   μ g / m 3 -y was associated with increased lung cancer risk (HR = 1.93 ; 95% CI: 1.24, 3.03), but the risk declined at the highest exposures (HR = 1.29 ; 95% CI: 0.74, 2.26). We also observed a significant trend in non-Hodgkin lymphoma (NHL) risk with increasing 20-y lagged cumulative REC (HR Tertile 3  vs. Tertile 1 = 3.12 ; 95% CI: 1.00, 9.79; p -trend = 0.031 ).

DISCUSSION

Increased risks of lung cancer mortality observed in the original study were sustained. Observed associations between diesel exposure and risk of death from NHL and the excesses in deaths for diseases of the respiratory and cardiovascular system, including ischemic heart disease and cerebrovascular disease, warrant further study and provide evidence of the potential widespread public health impact of diesel exposure. https://doi.org/10.1289/EHP12840.

Nitrated Polycyclic Aromatic Hydrocarbon (Nitro-PAH) Signatures and Somatic Mutations in Diesel Exhaust-Exposed Bladder Tumors

BACKGROUND

Diesel exhaust is a complex mixture, including polycyclic aromatic hydrocarbons (PAH) and nitrated PAHs (nitro-PAH), many of which are potent mutagens and possible bladder carcinogens. To explore the association between diesel exposure and bladder carcinogenesis, we examined the relationship between exposure and somatic mutations and mutational signatures in bladder tumors.

METHODS

Targeted sequencing was conducted in bladder tumors from the New England Bladder Cancer Study. Using data on 797 cases and 1,418 controls, two-stage polytomous logistic regression was used to evaluate etiologic heterogeneity between bladder cancer subtypes and quantitative, lifetime estimates of respirable elemental carbon (REC), a surrogate for diesel exposure. Poisson regression was used to evaluate associations between REC and mutational signatures.

RESULTS

We observed significant heterogeneity in the diesel-bladder cancer risk relationship, with a strong positive association among cases with high-grade, nonmuscle invasive TP53-mutated tumors compared with controls [ORTop Tertile vs.Unexposed, 4.8; 95% confidence interval (CI), 2.2-10.5; Ptrend < 0.001; Pheterogeneity = 0.002]. In muscle-invasive tumors, we observed a positive association between diesel exposure and the nitro-PAH signatures of 1,6-dintropyrene (RR, 1.93; 95% CI, 1.28-2.92) and 3-nitrobenzoic acid (RR, 1.97; 95% CI, 1.33-2.92).

CONCLUSIONS

The relationship between diesel exhaust and bladder cancer was heterogeneous based on the presence of TP53 mutations in tumors, further supporting the link between PAH exposure and TP53 mutations in carcinogenesis. Future studies that can identify nitro-PAH signatures in exposed tumors are warranted to add human data supporting the link between diesel and bladder cancer.

IMPACT

This study provides additional insight into the etiology and possible mechanisms related to diesel exhaust-induced bladder cancer.

Long-term exposure to ambient air pollution and bladder cancer incidence in a pooled European cohort: the ELAPSE project

BACKGROUND

The evidence linking ambient air pollution to bladder cancer is limited and mixed.

METHODS

We assessed the associations of bladder cancer incidence with residential exposure to fine particles (PM2.5), nitrogen dioxide (NO2), black carbon (BC), warm season ozone (O3) and eight PM2.5 elemental components (copper, iron, potassium, nickel, sulfur, silicon, vanadium, and zinc) in a pooled cohort (N = 302,493). Exposures were primarily assessed based on 2010 measurements and back-extrapolated to the baseline years. We applied Cox proportional hazard models adjusting for individual- and area-level potential confounders.

RESULTS

During an average of 18.2 years follow-up, 967 bladder cancer cases occurred. We observed a positive though statistically non-significant association between PM2.5 and bladder cancer incidence. Hazard Ratios (HR) were 1.09 (95% confidence interval (CI): 0.93-1.27) per 5 µg/m3 for 2010 exposure and 1.06 (95% CI: 0.99-1.14) for baseline exposure. Effect estimates for NO2, BC and O3 were close to unity. A positive association was observed with PM2.5 zinc (HR 1.08; 95% CI: 1.00-1.16 per 10 ng/m3).

CONCLUSIONS

We found suggestive evidence of an association between long-term PM2.5 mass exposure and bladder cancer, strengthening the evidence from the few previous studies. The association with zinc in PM2.5 suggests the importance of industrial emissions.

Air pollution exposure and bladder, kidney and urinary tract cancer risk: A systematic review

BACKGROUND

Exposure to outdoor air pollution has been linked to lung cancer, and suspicion arose regarding bladder, kidney, and urinary tract cancer (urological cancers). However, most of evidence comes from occupational studies; therefore, little is known about the effect of exposure to air pollution on the risk of urological cancers in the general population.

METHOD

We systematically searched Medline, Scopus, and Web of Science for articles investigating the associations between long-term exposure to air pollution and the risk of urological cancer (incidence or mortality). We included articles using a specific air pollutant (PM₁₀, PM_2.5, …) or proxies (traffic, proximity index …). We assessed each study's quality with the Newcastle-Ottawa scale and rated the quality of the body of evidence for each pollutant-outcome with the GRADE approach. The different study methodologies regarding exposure or outcome prevented us to perform a meta-analysis.

RESULTS

twenty articles (four case-control, nine cohort, and seven ecologic) met our inclusion criteria and were included in this review: eighteen reported bladder, six kidney, and two urinary tract. Modeling air pollutants was the most common exposure assessment method. Most of the included studies reported positive associations between air pollution and urological cancer risk. However, only a few reached statistical significance (e.g. for bladder cancer mortality, adjusted odds-ratio of 1.13 (1.03-1.23) for an increase of 4.4 μg.m-3 of PM_2.5). Most studies inadequately addressed confounding, and cohort studies had an insufficient follow-up.

DISCUSSION

Overall, studies suggested positive (even though mostly non-significant) associations between air pollution exposure and bladder cancer mortality and kidney cancer incidence. We need more studies with better confounding control and longer follow-ups.

Occupational bladder cancer: A cross section survey of previous employments, tasks and exposures matched to cancer phenotypes

Objectives

Up to 10% of Bladder Cancers may arise following occupational exposure to carcinogens. We hypothesised that different cancer phenotypes reflected different patterns of occupational exposure.

Methods

Consecutive participants, with bladder cancer, self-completed a structured questionnaire detailing employment, tasks, exposures, smoking, lifestyle and family history. Our primary outcome was association between cancer phenotype and occupational details.

Results

We collected questionnaires from 536 patients, of whom 454 (85%) participants (352 men and 102 women) were included. Women were less likely to be smokers (68% vs. 81% Chi sq. p<0.001), but more likely than men to inhale environmental tobacco smoke at home (82% vs. 74% p = 0.08) and use hair dye (56% vs. 3%, p<0.001). Contact with potential carcinogens occurred in 282 (62%) participants (mean 3.1 per worker (range 0–14)). High-grade cancer was more common than low-grade disease in workers from the steel, foundry, metal, engineering and transport industries (p<0.05), and in workers exposed to crack detection dyes, chromium, coal/oil/gas by-products, diesel fumes/fuel/aircraft fuel and solvents (such as trichloroethylene). Higher staged cancers were frequent in workers exposed to Chromium, coal products and diesel exhaust fumes/fuel (p<0.05). Various workers (e.g. exposed to diesel fuels or fumes (Cox, HR 1.97 (95% CI 1.31–2.98) p = 0.001), employed in a garage (HR 2.19 (95% CI 1.31–3.63) p = 0.001), undertaking plumbing/gas fitting/ventilation (HR 2.15 (95% CI 1.15–4.01) p = 0.017), undertaking welding (HR 1.85 (95% CI 1.24–2.77) p = 0.003) and exposed to welding materials (HR 1.92 (95% CI 1.27–2.91) p = 0.002)) were more likely to have disease progression and receive radical treatment than others. Fewer than expected deaths were seen in healthcare workers (HR 0.17 (95% CI 0.04–0.70) p = 0.014).

Conclusions

We identified multiple occupational tasks and contacts associated with bladder cancer. There were some associations with phenotype, although our study design precludes robust assessment.

Diesel exhaust and bladder cancer risk by pathologic stage and grade subtypes

BACKGROUND

The International Agency for Research on Cancer (IARC) classifies diesel engine exhaust as carcinogenic to humans based on sufficient evidence for lung cancer. IARC noted, however, an increased risk of bladder cancer (based on limited evidence).

OBJECTIVE

To evaluate the association between quantitative, lifetime occupational diesel exhaust exposure and risk of urothelial cell carcinoma of the bladder (UBC) overall and according to pathological subtypes.

METHODS

Data from personal interviews with 1944 UBC cases, as well as formalin-fixed paraffin-embedded tumor tissue blocks, and 2135 controls were pooled from two case-control studies conducted in the U.S. and Spain. Lifetime occupational histories combined with exposure-oriented questions were used to estimate cumulative exposure to respirable elemental carbon (REC), a primary surrogate for diesel exhaust. Unconditional logistic regression and two-stage polytomous logistic regression were used to calculate odds ratios (ORs) and 95% confidence intervals (CIs), adjusting for smoking and other risk factors.

RESULTS

Exposure to cumulative REC was associated with an increased risk of UBC; workers with cumulative REC >396 μg/m³-years had an OR of 1.61 (95% CI, 1.08-2.40). At this level of cumulative exposure, similar results were observed in the U.S. and Spain, OR = 1.75 (95% CI, 0.97-3.15) and OR = 1.54 (95% CI, 0.89-2.68), respectively. In lagged analysis, we also observed a consistent increased risk among workers with cumulative REC >396 μg/m³-years (range of ORs = 1.52-1.93) for all lag intervals evaluated (5-40 years). When we accounted for tumor subtypes defined by stage and grade, a significant association between diesel exhaust exposure and UBC was apparent (global test for association p = 0.0019).

CONCLUSIONS

Combining data from two large epidemiologic studies, our results provide further evidence that diesel exhaust exposure increases the risk of UBC.

A link between environmental pollution and civilization disorders: a mini review

Most civilization disorders have a complex etiology, involving factors such as genetics, lifestyle, and environmental pollution (EP) due to different chemicals. Among harmful chemicals, the major ones include particulate matter (PM), nitrogen oxides, polycyclic aromatic hydrocarbons (PAHs), heavy metals, pesticides, plasticizers, polychlorinated biphenyls (PCBs), dioxins, furans, some food additives, hormones, and antibiotics. In fact, potential pollutants are countless and most of them have never been evaluated in terms of their toxicity and health risks, especially that new chemicals emerge all the time due to interactions between the existing ones. It is almost impossible to determine the effects of these new compounds on health. Previous studies have revealed a broad spectrum of diseases related to pollution. EP has been associated with an increased incidence of some malignancies, an increased rate of all-cause mortality, development or exacerbation of cardiovascular diseases, recurrent infections, impairment of intellectual and psychomotor development in children, development of type 2 diabetes, respiratory and immune system diseases, and also brain degenerative disorders. EP is an important cause of morbidity and mortality worldwide, generating high health care costs. Global pollution questions the common recommendation to eat vegetables, fruit, and fish regularly as part of a healthy diet, if they do not have ecological certification. Research in the fields of ecology, biology, and toxicology is needed to determine which environmental contaminants are the most hazardous to wildlife and humans and at what levels. Only an interdisciplinary cooperation and measures to raise public awareness could help improve environmental protection.

The strong focus on positive results in abstracts may cause bias in systematic reviews: a case study on abstract reporting bias

BACKGROUND

Research articles tend to focus on positive findings in their abstract, especially if multiple outcomes have been studied. At the same time, search queries in databases are generally limited to the abstract, title and keywords fields of an article. Negative findings are therefore less likely to be detected by systematic searches and to appear in systematic reviews. We aim to assess the occurrence of this 'abstract reporting bias' and quantify its impact in the literature on the association between diesel exhaust exposure (DEE) and bladder cancer.

METHODS

We set up a broad search query related to DEE and cancer in general. Full-texts of the articles identified in the search output were manually scanned. Articles were included if they reported, anywhere in the full-text, the association between DEE and bladder cancer. We assume that the use of a broad search query and manual full-text scanning allowed us to catch all the relevant articles, including those in which bladder cancer was not mentioned in the abstract, title or keywords.

RESULTS

We identified 28 articles. Only 12 of these (43%) had mentioned bladder in their abstract, title or keywords. A meta-analysis based on these 12 detectable articles yielded a pooled risk estimate of 1.10 (95% confidence interval [CI] 0.97-1.25), whereas the meta-analysis based on all 28 articles yielded a pooled estimate of 1.03 (95% CI 0.96-1.11).

CONCLUSIONS

This case study on abstract reporting bias shows that (a) more than half of all relevant articles were missed by a conventional search query and (b) this led to an overestimation of the pooled effect. Detection of articles will be improved if all studied exposure and outcome variables are reported in the keywords. The restriction on the maximum number of keywords should be lifted.

Interventions to Reduce Future Cancer Incidence from Diesel Engine Exhaust: What Might Work?

Exposure to diesel engine exhaust (DEE) contributes appreciably to the burden of occupational cancer. This study aims to estimate the potential impact of a range of interventions on the future burden of cancer from occupational exposure to DEE in Australia. The future excess fraction method, a novel method based on the lifetime risk approach, was used to model changes in the future burden of cancer among the Australian working age population exposed to DEE at work in 2012 under various intervention strategies. The interventions modeled were based on the widely accepted hierarchy of control model. At baseline, 600 (0.4%) future bladder and 4,450 (0.6%) future lung cancer cases over the lifetime of the cohort were estimated to be attributable to occupational exposure to DEE in those exposed in 2012. Up to 2,000 of these cases were estimated to be avoidable through the use of various interventions. Exhaust hoses (engineering controls) were estimated to be particularly effective. This study provides an indication of which intervention strategies may be most useful in reducing the future burden of cancer associated with occupational DEE exposure. These results show the potential effect of changing current exposure, rather than focusing on past exposures, and thus provide relevant information for policy planning.

Occupational health and safety of road haulage company employees

Background:

This paper follows up on a project that was launched in 2008 and contributed to the development of the new Italian Society of Occupational Medicine (SIML) guidelines for the road haulage industry.

Objective:

To reach a better understanding of occupational illness amongst truck drivers, in order to define appropriate health monitoring protocols and promote a healthy life-style.

Methods:

We assessed 673 male drivers (mean age 43.85 years, SD 9.56; mean working seniority 27.28 years, SD 10.59), employed by 46 different companies. The drivers, who were gradually recruited in the study over the years, had a maximum of 8 re-assessments each, for a total of 2608 examinations. We applied a survey protocol consisting in a medical examination, questionnaires for the most common risks and instrumental and laboratory tests in compliance with SIML guidelines.

Results:

We identified a total of 44 work-related diseases: 22 cases of noise-induced hearing loss (NIHL) and 22 cases of lumbar degenerative disc disease. As regards metabolic disorders, we observed 28 cases of diabetes mellitus, in most cases (71.4%) as a first diagnosis or under poor therapeutic control. We observed poorly-controlled hypertension in 103 drivers, the majority of whom (54%) were diagnosed for the first time. Over 30% of the workers in our study were obese and approximately 40% were tobacco smokers. We identified just 9 individuals (1.3%) with a positive toxicological screening for use of recreational drugs. Our data confirm a high prevalence of occupational illness amongst truck drivers. Cardiovascular and metabolic conditions require close monitoring.

Cancer Incidence in Suriname from 1980 through 2000 a Descriptive Study

Background and aims

Current data on the epidemiology of cancer in the Republic of Suriname are scant and incomplete. In this study, incidence rates of the histopathologically confirmed malignancies in the country from 1980 through 2000 were inventoried.

Patients and methods

Numbers of diagnoses, as well as patient information, were acquired from the Pathology Laboratory. The General Bureau of Statistics of Suriname provided relevant demographic information. For each year, crude incidence and sex-specific rates were calculated for: cancer overall; the most frequent cancer sites; age strata 0-19, 20-49, and 50+ years; as well as for the presumably largest, second largest, and third largest ethnic group, viz. the Hindustani, Creole, and Javanese. From these data, average rates were calculated, which were expressed as mean ± SD per 100,000 population per year, or per 100,000 males or females per year.

Results

Average yearly crude and sex-specific incidence rates for cancer overall were 70 ± 12: 59 ± 9 for men and 83 ± 12 for women. The leading cancer sites were cervix uteri (sex-specific rate of 22.1 ± 5.1) as well as gastrointestinal tract, breast, hematological system, prostate, head and neck, lung, and liver (sex-specific rates ranging from 2 to 17). The relatively high rate of cervical cancer was for an important part responsible for the 1.4-fold female over male overall cancer excess. Incidence rates of most cancers increased from age group 20-49 years on, being highest after age 50+ years, but hematological malignancies occurred in all age groups with rates of 1-3 new cases per 100,000 males or females per year. Cancer was in general 2-6 times more common in Creole than in Hindustani and Javanese. However, cervical cancer was seen as often in Hindustani as in Creole. Most cases of primary liver cancer involved, besides Creole of both genders, Javanese males. Thyroid cancer occurred more frequently in Hindustani women.

Conclusions

The data from the study suggest that the incidence profile of cancer in Suriname may resemble that of most developing countries. It was relatively low for cancer overall as well as for most individual sites, but relatively high for cervical cancer, thus producing the characteristic female over male excess. More detailed studies on the peculiarities in the ethnic distribution of cancer may help to shed more light on the etiology of certain malignancies.

Is There an Association Between Ambient Air Pollution and Bladder Cancer Incidence? Analysis of 15 European Cohorts

BACKGROUND

Ambient air pollution contains low concentrations of carcinogens implicated in the etiology of urinary bladder cancer (BC). Little is known about whether exposure to air pollution influences BC in the general population.

OBJECTIVE

To evaluate the association between long-term exposure to ambient air pollution and BC incidence.

DESIGN, SETTING, AND PARTICIPANTS

We obtained data from 15 population-based cohorts enrolled between 1985 and 2005 in eight European countries (N=303431; mean follow-up 14.1 yr). We estimated exposure to nitrogen oxides (NO2 and NOx), particulate matter (PM) with diameter <10μm (PM10), <2.5μm (PM2.5), between 2.5 and 10μm (PM2.5-10), PM2.5absorbance (soot), elemental constituents of PM, organic carbon, and traffic density at baseline home addresses using standardized land-use regression models from the European Study of Cohorts for Air Pollution Effects project.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

We used Cox proportional-hazards models with adjustment for potential confounders for cohort-specific analyses and meta-analyses to estimate summary hazard ratios (HRs) for BC incidence.

RESULTS AND LIMITATIONS

During follow-up, 943 incident BC cases were diagnosed. In the meta-analysis, none of the exposures were associated with BC risk. The summary HRs associated with a 10-μg/m3 increase in NO2 and 5-μg/m3 increase in PM2.5 were 0.98 (95% confidence interval [CI] 0.89-1.08) and 0.86 (95% CI 0.63-1.18), respectively. Limitations include the lack of information about lifetime exposure.

CONCLUSIONS

There was no evidence of an association between exposure to outdoor air pollution levels at place of residence and risk of BC.

PATIENT SUMMARY

We assessed the link between outdoor air pollution at place of residence and bladder cancer using the largest study population to date and extensive assessment of exposure and comprehensive data on personal risk factors such as smoking. We found no association between the levels of outdoor air pollution at place of residence and bladder cancer risk.

Smoking status, usual adult occupation, and risk of recurrent urothelial bladder carcinoma: data from The Cancer Genome Atlas (TCGA) Project

PURPOSE

Tobacco smoking and occupational exposures are the leading risk factors for developing urothelial bladder carcinoma (UBC), yet little is known about the contribution of these two factors to risk of UBC recurrence. We evaluated whether smoking status and usual adult occupation are associated with time to UBC recurrence for 406 patients with muscle-invasive bladder cancer submitted to The Cancer Genome Atlas (TCGA) project.

METHODS

Kaplan-Meier and Cox proportional hazard methods were used to assess the association between smoking status, employment in a high-risk occupation for bladder cancer, occupational diesel exhaust exposure, and 2010 Standard Occupational Classification group and time to UBC recurrence.

RESULTS

Data on time to recurrence were available for 358 patients over a median follow-up time of 15 months. Of these, 133 (37.2%) experienced a recurrence. Current smokers who smoked for more than 40 pack-years had an increased risk of recurrence compared to never smokers (HR 2.1, 95% CI 1.1, 4.1). Additionally, employment in a high-risk occupation was associated with a shorter time to recurrence (log-rank p = 0.005). We found an increased risk of recurrence for those employed in occupations with probable diesel exhaust exposure (HR 1.8, 95% CI 1.1, 3.0) and for those employed in production occupations (HR 2.0, 95% CI 1.1, 3.6).

CONCLUSIONS

These findings suggest smoking status impacts risk of UBC recurrence, although several previous studies provided equivocal evidence regarding this association. In addition to the known causal relationship between occupational exposure and bladder cancer risk, our study suggests that occupation may also be related to increased risk of recurrence.

Modifiable risk factors for the prevention of bladder cancer: a systematic review of meta-analyses

Each year, 430,000 people are diagnosed with bladder cancer. Due to the high recurrence rate of the disease, primary prevention is paramount. Therefore, we reviewed all meta-analyses on modifiable risk factors of primary bladder cancer. PubMed, Embase and Cochrane database were systematically searched for meta-analyses on modifiable risk factors published between 1995 and 2015. When appropriate, meta-analyses (MA) were combined in meta-meta-analysis (MMA). If not, the most comprehensive MA was selected based on the number of primary studies included. Probability of causation was calculated for individual factors and a subset of lifestyle factors combined. Of 1496 articles identified, 5 were combined in MMA and 21 were most comprehensive on a single risk factor. Statistically significant associations were found for current (RR 3.14) or former (RR 1.83) cigarette smoking, pipe (RR 1.9) or cigar (RR 2.3) smoking, antioxidant supplementation (RR 1.52), obesity (RR 1.10), higher physical activity levels (RR 0.86), higher body levels of selenium (RR 0.61) and vitamin D (RR 0.75), and higher intakes of: processed meat (RR 1.22), vitamin A (RR 0.82), vitamin E (RR 0.82), folate (RR 0.84), fruit (RR 0.77), vegetables (RR 0.83), citrus fruit (RR 0.85), and cruciferous vegetables (RR 0.84). Finally, three occupations with the highest risk were tobacco workers (RR 1.72), dye workers (RR 1.58), and chimney sweeps (RR 1.53). The probability of causation for individual factors ranged from 4 to 68 %. The combined probability of causation was 81.8 %. Modification of lifestyle and occupational exposures can considerably reduce the bladder cancer burden. While smoking remains one of the key risk factors, also several diet-related and occupational factors are very relevant.

Occupational risk factors for relapse-free survival in bladder cancer patients

The influence of occupational risk factors on bladder cancer development is well investigated. However, studies on the influence on bladder cancer prognosis are rare. Therefore, it was of interest to investigate the time to first relapse in the follow-ups of three case-control series from Dortmund, Neuss, and Lutherstadt Wittenberg, Germany. Relapse-free survival of in total 794 urinary bladder cancer patients (Dortmund 174, Neuss 407, Lutherstadt Wittenberg 213) was derived from medical records. Cox regression models were used to determine the impact of profession and exposure to bladder carcinogens if the risk factor was present in at least four cases. One or several relapses were observed in 416 cases (52%). Median time to first relapse was 0.94 yr. Ten professions were observed in at least 4 patients. No significant associations were found. However, workers in the leather industry (n = 4), printing industry (n = 4), transportation (n = 43), and chemical industry (n = 40) and locksmiths/mechanics (n = 44) showed shorter relapse-free times. No trend to shorter relapse-free time was observed for miners (n = 42), agriculturists (n = 18), painters/lacquerers (n = 21), colorant production and processing workers (n = 7), foundry workers (n = 5), and persons exposed to aromatic amines (n = 45). Although the follow-up comprised nearly 800 cases, data on occupations and exposures of interest were not sufficient to obtain significant results. However, first results indicated potential associations that are worth further investigations.

National Survey of US Long-Haul Truck Driver Health and Injury: health behaviors

OBJECTIVE

To compare selected health behaviors and body mass index (modifiable risk factors) of US long-haul truck drivers to the US working population by sex.

METHODS

The National Survey of US Long-Haul Truck Driver Health and Injury interviewed a nationally representative sample of long-haul truck drivers (n = 1265) at truck stops. Age-adjusted results were compared with national health surveys.

RESULTS

Compared with US workers, drivers had significantly higher body mass index, current cigarette use, and pack-years of smoking; lower prevalence of annual influenza vaccination; and generally lower alcohol consumption. Physical activity level was low for most drivers, and 25% had never had their cholesterol levels tested.

CONCLUSIONS

Working conditions common to long-haul trucking may create significant barriers to certain healthy behaviors; thus, transportation and health professionals should address the unique work environment when developing interventions for long-haul drivers.

Bladder cancer and occupational exposure to diesel and gasoline engine emissions among Canadian men

The International Agency for Research on Cancer has classified diesel exhaust as a carcinogen based on lung cancer evidence; however, few studies have investigated the effect of engine emissions on bladder cancer. The purpose of this study was to investigate the association between occupational exposure to diesel and gasoline emissions and bladder cancer in men using data from the Canadian National Enhanced Cancer Surveillance System; a population‐based case–control study. This analysis included 658 bladder cancer cases and 1360 controls with information on lifetime occupational histories and a large number of possible cancer risk factors. A job‐exposure matrix for engine emissions was supplemented by expert review to assign values for each job across three dimensions of exposure: concentration, frequency, and reliability. Odds ratios (OR) and their corresponding 95% confidence intervals were estimated using logistic regression. Relative to unexposed, men ever exposed to high concentrations of diesel emissions were at an increased risk of bladder cancer (OR = 1.64, 0.87–3.08), but this result was not significant, and those with >10 years of exposure to diesel emissions at high concentrations had a greater than twofold increase in risk (OR = 2.45, 1.04–5.74). Increased risk of bladder cancer was also observed with >30% of work time exposed to gasoline engine emissions (OR = 1.59, 1.04–2.43) relative to the unexposed, but only among men that had never been exposed to diesel emissions. Taken together, our findings support the hypothesis that exposure to high concentrations of diesel engine emissions may increase the risk of bladder cancer.

Occupational exposure to pesticides and bladder cancer risk

BACKGROUND

In the developed world, occupational exposures are a leading cause of bladder cancer. A few studies have suggested a link between pesticide exposures among agricultural populations and bladder cancer.

METHODS

We used data from the Agricultural Health Study, a prospective cohort study which includes 57 310 pesticide applicators with detailed information on pesticide use, to evaluate the association between pesticides and bladder cancer. We used Poisson regression to calculate rate ratios (RRs) and 95% confidence intervals (CIs) to estimate the association between each of 65 pesticides and 321 incident bladder cancer cases which accrued over the course of follow-up (1993-2011), adjusting for lifestyle and demographic and non-pesticide farm-related exposures, including those previously linked to bladder cancer. We conducted additional analyses stratified by smoking status (never, former, current).

RESULTS

We observed associations with bladder cancer risk for two imidazolinone herbicides, imazethapyr and imazaquin, which are aromatic amines. Ever use of imazaquin (RR = 1.54, 95% CI: 1.05, 2.26) was associated with increased risk whereas the excess risk among users of imazethapyr was evident among never smokers (RR in highest quartile vs non-exposed = 3.03, 95% CI: 1.46, 6.29, P-interaction = 0.005). We also observed increased risks overall and among never smokers for use of several chlorinated pesticides including chlorophenoxy herbicides and organochlorine insecticides.

CONCLUSIONS

Several associations between specific pesticides and bladder cancer risk were observed, many of which were stronger among never smokers, suggesting that possible risk factors for bladder cancer may be more readily detectable in those unexposed to potent risk factors like tobacco smoke.

Medical follow-up for workers exposed to bladder carcinogens: the French evidence-based and pragmatic statement

BACKGROUND

The aim of this work was to establish recommendations for the medical follow-up of workers currently or previously exposed to carcinogenic substances for the bladder.

METHODS

A critical synthesis of the literature was conducted. Sectors of activity where workers are or were exposed to carcinogenic substances for the bladder were listed and classified according to the level of bladder cancer risk. Performances of techniques available for the targeted screening of bladder cancer were analysed, including a simulation of results among high-risk populations in France.

RESULTS

The risk level for the professional group and the latency period between the start of exposure and the natural history of the disease were selected to define a targeted screening protocol. The NMP22BC test, exclusive haematuria testing, and combinations of urine cytology with, respectively, the NMP22BC test and haematuria test, generated an extremely high proportion of false positive results.

CONCLUSION

Urine cytology is the test that offers the best specificity. Although poor for all bladder cancer stages and grades combined, its sensitivity is better for high grades, which require early diagnosis since late-stage cancers are of very poor prognosis. These results suggest that urine cytology is currently the only technique suitable for proposal within the context of a first line targeted screening strategy for occupational bladder cancer. An algorithm summarising the recommended medical follow-up for workers currently or previously exposed to carcinogenic substances for the bladder is proposed, based on the level of risk of bladder cancer.

Constitutional and occupational risk factors associated with bladder cancer

OBJECTIVE

Bladder carcinoma (BC) is the fourth most common type of cancer in males from Western countries, with primary prevention an important healthcare challenge. We review the associated constitutional and occupational risk factors (RF), with greater or lesser scientific evidence, in the aetiology of BC.

MATERIAL AND METHODS

Literature review of the last 25 years of the constitutional and occupational RF associated with BC, conducted on MedLine, CancerLit, Science Citation Index and Embase. The search profiles were Risk factors/Genetic factors/Genetic polymorphisms/Epidemiology/Occupational factors and Bladder cancer.

RESULTS

The main RF were a) age and gender (diagnosed at age 65 and over, with a 4:1 ratio of males to females); b) race, ethnicity and geographic location (predominantly in Caucasians and in Southern European countries); c) genetic (N-acetyltransferase-2 and glutathione s-transferase M1 gene mutations, which significantly increase the risk for BC); d) occupational, which represent 5%-10% of BC RF; and f) occupations with high BC risk, such as aluminium production, the manufacture of dyes, paints and colourings, the rubber industry and the extraction and industrial use of fossil fuels.

CONCLUSIONS

BC is the end result of the variable combination of constitutional and environmental RF, the majority of which are unknown. The most significant constitutional RF are related to age, gender, race, ethnicity geographic location and genetic polymorphisms. The main occupational RF are those related to aromatic amines and polycyclic aromatic hydrocarbons.

Characterisation of nano- and micron-sized airborne and collected subway particles, a multi-analytical approach

Continuous daily measurements of airborne particles were conducted during specific periods at an underground platform within the subway system of the city center of Stockholm, Sweden. Main emphasis was placed on number concentration, particle size distribution, soot content (analyzed as elemental and black carbon) and surface area concentration. Conventional measurements of mass concentrations were conducted in parallel as well as analysis of particle morphology, bulk- and surface composition. In addition, the presence of volatile and semi volatile organic compounds within freshly collected particle fractions of PM(10) and PM(2.5) were investigated and grouped according to functional groups. Similar periodic measurements were conducted at street level for comparison. The investigation clearly demonstrates a large dominance in number concentration of airborne nano-sized particles compared to coarse particles in the subway. Out of a mean particle number concentration of 12000 particles/cm(3) (7500 to 20000 particles/cm(3)), only 190 particles/cm(3) were larger than 250 nm. Soot particles from diesel exhaust, and metal-containing particles, primarily iron, were observed in the subway aerosol. Unique measurements on freshly collected subway particle size fractions of PM(10) and PM(2.5) identified several volatile and semi-volatile organic compounds, the presence of carcinogenic aromatic compounds and traces of flame retardants. This interdisciplinary and multi-analytical investigation aims to provide an improved understanding of reported adverse health effects induced by subway aerosols.

Mortality among Members of a Truck Driver Trade Association

Previous studies report that truck drivers are at increased risk for illness and on-the-job mortality. It is unknown whether owner-operator truck drivers face the same risks as employee drivers, yet few studies have targeted owner-operators as a study population. This study examined the overall and cause-specific mortality ratios for a cohort with owner-operator truck drivers constituting 69% of the study population. Of the 26 major disease classifications and 92 specific causes of death examined, only mortality due to transportation accidents was significantly elevated (standardized mortality ratio = 1.52, 95% confidence interval = 1.36–1.70). Leading causes of death were ischemic heart disease and lung cancer, although risk was below that of the general population. Transportation accidents pose a particular hazard for members of the trade association. The absence of excess disease mortality deserves careful interpretation, and may be due to both a strong healthy worker effect and a short monitoring period.

Postmenopausal breast cancer is associated with exposure to traffic-related air pollution in Montreal, Canada: a case-control study

BACKGROUND

Only about 30% of cases of breast cancer can be explained by accepted risk factors. Occupational studies have shown associations between the incidence of breast cancer and exposure to contaminants that are found in ambient air.

OBJECTIVES

We sought to determine whether the incidence of postmenopausal breast cancer is associated with exposure to urban air pollution.

METHODS

We used data from a case-control study conducted in Montreal, Quebec, in 1996-1997. Cases were 383 women with incident invasive breast cancer, and controls were 416 women with other incident, malignant cancers, excluding those potentially associated with selected occupational exposures. Concentrations of nitrogen dioxide (NO2) were measured across Montreal in 2005-2006. We developed a land-use regression model to predict concentrations of NO2 across Montreal for 2006, and developed two methods to extrapolate the estimates to 1985 and 1996. We linked these estimates to addresses of residences of subjects at time of interview. We used unconditional logistic regression to adjust for accepted and suspected risk factors and occupational exposures.

RESULTS

For each increase of 5 ppb NO2 estimated in 1996, the adjusted odds ratio was 1.31 (95% confidence interval, 1.00-1.71). Although the size of effect varied somewhat across periods, we found an increased risk of approximately 25% for every increase of 5 ppb in exposure.

CONCLUSIONS

We found evidence of an association between the incidence of postmenopausal breast cancer and exposure to ambient concentrations of NO2. Further studies are needed to confirm whether NO2 or other components of traffic-related pollution are indeed associated with increased risks.

Cancer morbidity among Danish male urban bus drivers: A historical cohort study

OBJECTIVE

To investigate whether urban bus drivers are at increased risk for cancer.

METHODS

Urban bus drivers in a cohort established in 1978 in the three largest cities of Denmark were followed-up in the Danish Cancer Registry until the end of 2003, and relative risks for cancers were estimated.

RESULTS

Of 2,037 men included 70% reported in 1978 that they smoked. The standardized incidence ratio (SIR) for cancer in comparison with that of other male residents of the three cities was 1.09 [1.0-1.2]. The excess was due mainly to increased risks for cancers of the bladder (SIR, 1.6; 1.2-2.0) and lung (1.2; 1.0-1.4). In an analysis with internal comparisons and adjustment for smoking, we found no significant associations between duration of employment and increased risks for cancers at these two sites.

CONCLUSIONS

In this long-term follow-up study we found little evidence of a causal association between employment as an urban bus driver in Denmark and subsequent cancer.

In-depth investigation of the molecular pathogenesis of bladder cancer in a unique 26-year old patient with extensive multifocal disease: a case report

Background

The molecular characteristics and the clinical disease course of bladder cancer (BC) in young patients remain largely unresolved. All patients are monitored according to an intensive surveillance protocol and we aim to gain more insight into the molecular pathways of bladder tumors in young patients that could ultimately contribute to patient stratification, improve patient quality of life and reduce associated costs. We also determined whether a biomarker-based surveillance could be feasible.

Case Presentation

We report a unique case of a 26-year-old Caucasian male with recurrent non-muscle invasive bladder tumors occurring at a high frequency and analyzed multiple tumors (maximal pTaG2) and urine samples of this patient. Analysis included FGFR3 mutation detection, FGFR3 and TP53 immunohistochemistry, mircosatellite analysis of markers on chromosomes 8, 9, 10, 11 and 17 and a genome wide single nucleotide polymorphism-array (SNP). All analyzed tumors contained a mutation in FGFR3 and were associated with FGFR3 overexpression. None of the tumors showed overexpression of TP53. We found a deletion on chromosome 9 in the primary tumor and this was confirmed by the SNP-array that showed regions of loss on chromosome 9. Detection of all recurrences was possible by urinary FGFR3 mutation analysis.

Conclusions

Our findings would suggest that the BC disease course is determined by not only a patient's age, but also by the molecular characteristics of a tumor. This young patient contained typical genetic changes found in tumors of older patients and implies a clinical disease course comparable to older patients. We demonstrate that FGFR3 mutation analysis on voided urine is a simple non-invasive method and could serve as a feasible follow-up approach for this young patient presenting with an FGFR3 mutant tumor.

Traffic air pollution and risk of death from bladder cancer in Taiwan using petrol station density as a pollutant indicator

To investigate the relationship between air pollution and risk of death from bladder cancer, a matched cancer case-control study was conducted using deaths that occurred in Taiwan from 1997 through 2006. Data for all eligible bladder cancer deaths were obtained from the Bureau of Vital Statistics of the Taiwan Provincial Department of Health. The control group consisted of individuals who died from causes other than cancer or diseases associated with genitourinary problems. The controls were pair matched to the cases by gender, year of birth, and year of death. Each matched control was selected randomly from the set of possible controls for each case. Data for the number of petrol stations in study municipalities were collected from the two major petroleum supply companies, Chinese Petroleum Corporation (CPC) and Formosa Petrochemical Corporation (FPCC). The petrol station density (per square kilometer) (PSD) for study municipalities was used as an indicator of a subject's exposure to benzene and other hydrocarbons present in ambient evaporative losses of petrol or to air emissions from motor vehicles. The subjects were divided into tertiles according to PSD in their residential municipality. The present study showed that individuals who resided in municipalities with high PSD levels were at an increased risk of death from bladder cancer compared to subjects living in municipalities with a low PSD level; however, the differences are not statistically significant. The findings of this study warrant further investigation of the role of vehicular air pollutant emissions in the etiology of bladder cancer development.

Ambient exposure to criteria air pollutants and risk of death from bladder cancer in Taiwan

To investigate the relationship between air pollution and risk of death from bladder cancer, the authors conducted a matched case-control study using deaths that occurred in Taiwan from 1995 through 2005. Data on all eligible bladder cancer deaths were obtained from the Bureau of Vital Statistics of the Taiwan Provincial Department of Health. The control group consisted of people who died from causes other than cancer or diseases associated with genitourinary problems. The controls were pair matched to the cases by sex, year of birth, and year of death. Each matched control was selected randomly from the set of possible controls for each case. Classification of exposure to municipality air pollution was based on the measured levels of nitrogen dioxide and sulfur dioxide. The results of the present study show that there is a significant positive association between the levels of air pollution and bladder cancer mortality. The adjusted odds ratios (95% confidence interval) were 1.37 (1.03-1.82) for the group with medium air pollution level and 1.98 (1.36-2.88) for the group with high air pollution level when compared to the group with the low air pollution level. Trend analyses showed statistically significant trend in risk of death from bladder cancer with increasing air pollution level. The findings of this study warrant further investigation of the role of air pollutants in the etiology of bladder cancer.

Occupational risk factors

The association between exposure to selected chemical carcinogens, occupations or industries and bladder cancer is well established, and it is estimated that 20-27% of bladder cancers are attributable to occupational exposures. The risk of bladder cancer stemming from an occupational exposure depends not only on compound carcinogenicity, exposure intensity and workplace characteristics, but also on individual susceptibility to these cancers. Regulatory controls in industrialized nations have resulted in a decreased burden of exposure to bladder carcinogens in the workplace. Unfortunately, the same is unlikely in many developing countries, where risky technologies may have been transferred from more developed countries, and where enforcement of regulations and worker protection are likely to be less stringent.

Association of bladder cancer with residential exposure to petrochemical air pollutant emissions in Taiwan

To investigate the relationship between petrochemical air pollution and risk of death due to bladder cancer, studies were conducted using a matched cancer case-control model based upon deaths that occurred in Taiwan from 1995 through 2005. Data on all eligible bladder cancer deaths were obtained from the Bureau of Vital Statistics of the Taiwan Provincial Department of Health. The control group consisted of individuals who died from causes other than neoplasms or diseases associated with genitourinary problems. The controls were pair matched to the cases by gender, year of birth, and year of death. Each matched control was selected randomly from the set of possible controls for each case. The proportion of a municipality's total population employed in the petrochemical industry in a municipality was used as an indicator of a resident's exposure to air emissions from the petrochemical industry. The subjects were divided into three levels (< or =25th percentile; 25th-50th percentile; >50th percentile). Subjects who lived in the group of municipalities characterized by the high levels of petrochemical air pollution had a significantly higher risk of death attributed to bladder cancer than subjects in the group that lived in municipalities with the lowest petrochemical air pollution levels, after controlling for possible confounders. The findings of this study warrant further investigation of the role of petrochemical air pollution in the etiology of bladder cancer.

Cancer incidence among male Massachusetts firefighters, 1987-2003

BACKGROUND

Firefighters are known to be exposed to recognized or probable carcinogens. Previous studies have found elevated risks of several types of cancers in firefighters.

METHODS

Standardized morbidity odds ratio (SMORs) were used to evaluate the cancer risk in white, male firefighters compared to police and all other occupations in the Massachusetts Cancer Registry from 1986 to 2003. Firefighters and police were identified by text search of the usual occupation field. All other occupations included cases with identifiable usual occupations not police or firefighter. Control cancers were those not associated with firefighters in previous studies.

RESULTS

Risks were moderately elevated among firefighters for colon cancer (SMOR = 1.36, 95% CI: 1.04-1.79), and brain cancer (SMOR = 1.90, 95% CI: 1.10-3.26). Weaker evidence of increased risk was observed for bladder cancer (SMOR = 1.22, 95% CI: 0.89-1.69), kidney cancer (SMOR = 1.34, 95% CI: 0.90-2.01), and Hodgkin's lymphoma (SMOR = 1.81, 95% CI: 0.72-4.53).

CONCLUSIONS

These findings are compatible with previous reports, adding to the evidence that firefighters are at increased risk of a number of types of cancer.

Projecting individualized probabilities of developing bladder cancer in white individuals

PURPOSE

There has been no risk assessment model for bladder cancer (BC). We developed the first model incorporating mutagen sensitivity and epidemiologic factors to predict BC risk.

PATIENTS AND METHODS

We used epidemiologic and genetic data from a large case-control study to build the models and constructed receiver operating characteristic curves. The area under the curve (AUC) was used to evaluate model discriminatory ability. We also projected absolute risk of developing BC by taking into account competing causes of death.

RESULTS

The study included 678 white BC patients and 678 controls. Significant risk factors in the epidemiologic model included pack-years smoked and exposures to diesel, aromatic amines, dry cleaning fluids, radioactive materials, and arsenic. This model yielded good discriminatory ability (AUC = 0.70; 95% CI, 0.67 to 0.73). When mutagen sensitivity data were incorporated, the AUC increased to 0.80 (95% CI, 0.72 to 0.82). The models showed excellent concordance in the internal validation. We also computed an easy to use ordinal risk score and provided examples for projecting absolute risk.

CONCLUSION

We have developed the first risk prediction model for BC. The enhanced model integrating the genetic factor exhibited excellent discriminatory ability. Our model only requires an individual to answer a few simple questions during a clinic visit to project individualized probability. This model may be used as a basis for developing a Web-based tool for BC risk assessment. Validation of our model in an external population is an essential next step towards practical use in the clinical setting.

Cause-specific mortality in the unionized U.S. trucking industry

BACKGROUND

Occupational and population-based studies have related exposure to fine particulate air pollution, and specifically particulate matter from vehicle exhausts, to cardiovascular diseases and lung cancer.

OBJECTIVES

We have established a large retrospective cohort to assess mortality in the unionized U.S. trucking industry. To provide insight into mortality patterns associated with job-specific exposures, we examined rates of cause-specific mortality compared with the general U.S. population.

METHODS

We used records from four national trucking companies to identify 54,319 male employees employed in 1985. Cause-specific mortality was assessed through 2000 using the National Death Index. Expected numbers of all and cause-specific deaths were calculated stratifying by race, 10-year age group, and calendar period using U.S. national reference rates. Standardized mortality ratios (SMRs) and 95% confidence intervals (CIs) were calculated for the entire cohort and by job title.

RESULTS

As expected in a working population, we found a deficit in overall and all-cancer mortality, likely due to the healthy worker effect. In contrast, compared with the general U.S. population, we observed elevated rates for lung cancer, ischemic heart disease, and transport-related accidents. Lung cancer rates were elevated among all drivers (SMR = 1.10; 95% CI, 1.02-1.19) and dockworkers (SMR = 1.10; 95% CI, 0.94-1.30); ischemic heart disease was also elevated among these groups of workers [drivers, SMR = 1.49 (95% CI, 1.40-1.59); dockworkers, SMR = 1.32 (95% CI, 1.15-1.52)], as well as among shop workers (SMR = 1.34; 95% CI, 1.05-1.72).

CONCLUSIONS

In this detailed assessment of specific job categories in the U.S. trucking industry, we found an excess of mortality due to lung cancer and ischemic heart disease, particularly among drivers.

Epidemiology of urinary bladder cancer: from tumor development to patient’s death

Urinary bladder cancer (UBC) ranks ninth in worldwide cancer incidence. It is more frequent in men than in women. We review the main established/proposed factors, both environmental and genetic, associated with bladder cancer etiology and prognosis. Data were extracted from previous reviews and original articles identified from PubMed searches, reference lists, and book chapters dealing with the reviewed topics. Evaluation and consensus of both the contribution of each factor in bladder cancer burden and the appropriateness of the available evidences was done during an ad hoc meeting held during the 18th Congress of the European Society for Urological Research. Cigarette smoking and specific occupational exposures are the main known causes of UBC. Phenacetin, chlornaphazine and cyclophosphamide also increase the risk of bladder cancer. Chronic infection by Schistosoma haematobium is a cause of squamous cell carcinoma of the bladder. NAT2 slow acetylator and GSTM1 null genotypes are associated with an increased risk of this cancer. Vegetables and fresh fruits protect against this tumor. Regarding prognosis, there is little knowledge on the predictive role of environmental exposures and genetic polymorphisms on tumor recurrence and progression and patient's death. Although active tobacco smoking is the most commonly studied factor, no definitive conclusion can be drawn from the literature. More research is needed regarding the effect of complex etiological factors in bladder carcinogenesis. Subgroup analysis according to stage, grade, and molecular features may help in identifying specific etiological and prognostic factors involved in different bladder cancer progression pathways.

Acute changes in sputum IL-10 following underground exposure to diesel exhaust

INTRODUCTION

Although exposure to diesel exhaust has been linked with adverse health effects, little is known about the acute effects of exposure in the underground workplace.

METHODS

Cross-shift spirometry and sputum induction were completed on twelve subjects associated with comminuted rock removal (mucking) operations in an underground copper mine using diesel powered and pneumatic equipment on separate days, and sputum collected on a baseline non-exposure day as well.

RESULTS

For diesel operations, elemental carbon exposure averaged 538 +/- 512 microg/m(3) during the 1-2 hour operations. Sputum interleukin-10 decreased with diesel exhaust using one ELISA assay (3.69 v. 2.32 pg/ml, p = 0.015), but increased when measured with a different ELISA kit (0.18 v. 0.59 pg/ml, p = 0.019), consistent with an overall decline in IL-10 protein concentration but an increase in the biologically active form. Sputum interleukin-6 decreased with exposure to diesel exhaust, although this change lost statistical significance when restricted to non-smokers. There were no significant changes in spirometry, interleukins 1beta, 4, and 8, tumor necrosis factor alpha or 8-hydroxy-2'-deoxyguanosine.

CONCLUSION

High levels of diesel exhaust can result in rapid changes in sputum IL-10, suggesting possible protein modification.

Does occupational exposure to PAHs, diesel and aromatic amines interact with smoking and metabolic genetic polymorphisms to increase the risk on bladder cancer?; The Belgian case control study on bladder cancer risk

To investigate the association between occupational exposure to polycyclic aromatic hydrocarbons, aromatic amines and diesel and bladder cancer risk and the modification by smoking and metabolic polymorphisms, have we recruited 200 cases and 385 population controls. The adjusted OR of bladder cancer was 5.75 (95%CI 2.09-15.83) comparing the highest tertile of the cumulative probability of occupational exposure to aromatic amines with no occupational exposure. A possible interaction between occupational exposures to aromatic amines and smoking was found. The increased ORs of GSTM1, GSTT1, NAT2 and SULT1A1 among those ever occupational exposed was explored by estimating the false-positive report probability. We confirm that occupational exposure to aromatic amines is associated with an increase in bladder cancer risk.

Imaging of Bladder Cancer

Bladder cancer is a heterogeneous and frequently multifocal disease with a variable clinical course. The management of bladder cancer is therefore challenging and complicated. CT and MR imaging have replaced the traditional excretory urography and are emerging as the imaging modalities of choice for work-up of patients who have bladder cancer. Imaging provides essential diagnostic information for detection, staging, and post-treatment follow-up of bladder cancer.

An Updated Review of the Literature: Risk Factors for Bladder Cancer with Focus on Occupational Exposures

Workplace exposures account for 5 to 25% of all bladder cancer cases. A critical review of the literature between 1938 and 2004 was performed, with a focus on occupational exposures. Occupational exposure to bladder carcinogens, particularly to beta-naphthylamine occur in a number of industries, including aromatic amine manufacture, rubber and cable manufacture, and dyestuff manufacture and use. Risks to workers in a number of new occupations and industries are reviewed. Nonoccupational risk factors that are known or at one time have been thought to increase the risk of bladder cancer are also discussed.

The Italian surveillance system for occupational cancers: characteristics, initial results, and future prospects

BACKGROUND

Occupational cancer monitoring is important for cancer prevention and public health protection. A surveillance system for identifying occupational cancer risks and cancer cases in Italy that are likely to be of occupational origin using information available in the Italian Social Security archives was created and assessed. Persons employed in the private sector, the employing company, its industrial sector, and years of employment are available in these archives.

METHODS

A method to find known occupational hazards was first tested using a case-control approach. Cases were from six Italian cancer registries (CRs) and controls were sampled from source populations and as "exposure" the economic sector of the employing company was used. The potential of using hospital discharge records as case sources was subsequently assessed: these cover larger populations and are available more quickly than CR case series.

RESULTS

In the CR-based study many known occupational cancer risks related to specific industrial sectors were identified. By using cases from hospital discharge records many industries at risk were identified, as well as cases of recent diagnosis likely to be of occupational origin. However, for some industrial sectors (e.g., the chemical industry) the approach was unable to detect any excess risk. Furthermore, information on employees in important areas like agriculture, self-employment, and the public sector is not available in the Social Security archives.

CONCLUSIONS

This approach appears to be a promising low-cost method for occupational cancer surveillance, at least for some industries, and can be easily implemented in other countries.

Occupational exposures to polycyclic aromatic hydrocarbons, and respiratory and urinary tract cancers: a quantitative review to 2005

BACKGROUND

Exposure to polycyclic aromatic hydrocarbons (PAHs) has been reported in several industries, including those of the aluminum production, coal gasification, coke production, iron and steel foundries, coal tar and related products, carbon black and carbon electrodes production.

PATIENTS AND METHODS

This paper reviews the results from cohort studies conducted on workers exposed to PAHs in these industries, with a focus on cancers of the respiratory and urinary tract.

RESULTS

An excess risk from lung/respiratory cancers was found in most industries, the pooled relative risk (RR) being 2.58 (95% CI 2.28-2.92) for coal gasification, 1.58 (95% CI 1.47-1.69) for coke production, 1.40 (95% CI 1.31-1.49) for iron and steel foundries, 1.51 (95% CI 1.28-1.78) for roofers and 1.30 (95% CI 1.06-1.59) for carbon black production. The evidence for cancers of the bladder and of the urinary system is less consistent, with a significant increased risk only for workers in aluminum production (pooled RR = 1.29, 95% CI 1.12-1.49), coal gasification (pooled RR = 2.39, 95% CI 1.36-4.21), and iron and steel foundries (pooled RR = 1.29, 95% CI 1.06-1.57).

CONCLUSIONS

Increased risks from lung and bladder cancers were found in PAH-related occupations. These were modest in most industries, apart from those for coal gasification, and whether they are due at least partially to some bias or confounding remains open to discussion.

Chronic obstructive pulmonary disease mortality in diesel-exposed railroad workers

Diesel exhaust is a mixture of combustion gases and ultrafine particles coated with organic compounds. There is concern whether exposure can result in or worsen obstructive airway diseases, but there is only limited information to assess this risk. U.S. railroad workers have been exposed to diesel exhaust since diesel locomotives were introduced after World War II, and by 1959, 95% of the locomotives were diesel. We conducted a case-control study of railroad worker deaths between 1981 and 1982 using U.S. Railroad Retirement Board job records and next-of-kin smoking, residential, and vitamin use histories. There were 536 cases with chronic obstructive pulmonary disease (COPD) and 1,525 controls with causes of death not related to diesel exhaust or fine particle exposure. After adjustment for age, race, smoking, U.S. Census region of death, vitamin use, and total years off work, engineers and conductors with diesel-exhaust exposure from operating trains had an increased risk of COPD mortality. The odds of COPD mortality increased with years of work in these jobs, and those who had worked >/= 16 years as an engineer or conductor after 1959 had an odds ratio of 1.61 (95% confidence interval, 1.12-2.30) . These results suggest that diesel-exhaust exposure contributed to COPD mortality in these workers. Further study is needed to assess whether this risk is observed after exposure to exhaust from later-generation diesel engines with modern emission controls.