Occupational exposure to solvents and gasoline and risk of cancers in the urinary tract among Finnish workers

Occupational exposure to organic solvents and risk of bladder cancer

BACKGROUND

Bladder cancer has been linked to several occupations that involve the use of solvents, including those used in the dry-cleaning industry.

OBJECTIVES

We evaluated exposure to solvents and risk of bladder cancer in 1182 incident cases and 1408 controls from a population-based study.

METHODS

Exposure to solvents was quantitatively assessed using a job-exposure matrix (CANJEM). Exposure to benzene, toluene and xylene often co-occur. Therefore, we created two additional sets of metrics for combined benzene, toluene and xylene (BTX) exposure: (1) CANJEM-based BTX metrics and (2) hybrid BTX metrics, using an approach that integrates the CANJEM-based BTX metrics together with lifetime occupational histories and exposure-oriented modules that captured within-job, respondent-specific details about tasks and chemicals. Adjusted odds ratios (ORs) and 95% confidence intervals (95% CI) were estimated using logistic regression.

RESULTS

Bladder cancer risks were increased among those ever exposed to benzene (OR = 1.63, 95% CI: 1.14-2.32), toluene (OR = 1.60, 95% CI: 1.06-2.43), and xylene (OR = 1.67, 95% CI: 1.13-2.48) individually. We further observed a statistically significant exposure-response relationship for cumulative BTX exposure, with a stronger association using the hybrid BTX metrics (ORQ1vsUnexposed = 1.26, 95% CI: 0.83-1.90; ORQ2vsUnexposed = 1.52, 95% CI: 1.00-2.31; ORQ3vsUnexposed = 1.88, 95% CI: 1.24-2.85; and ORQ4vsUnexposed = 2.23, 95% CI: 1.35-3.69) (p-trend=0.001) than using CANJEM-based metrics (p-trend=0.02).

IMPACT

There is limited evidence about the role of exposure to specific organic solvents, alone or in combination on the risk of developing bladder cancer. In this study, workers with increasing exposure to benzene, toluene, and xylene as a group (BTX) had a statistically significant exposure-response relationship with bladder cancer. Future evaluation of the carcinogenicity of BTX and other organic solvents, particularly concurrent exposure, on bladder cancer development is needed.

Occupational exposure to asbestos and risk of kidney cancer: an updated meta-analysis

Limited information is available on carcinogenicity of asbestos on non-respiratory organs. We aimed at conducted an updated systematic review and meta-analysis of cohort studies on occupational exposure to asbestos and risk of kidney cancer. We searched through three databases, PubMed, Embase and Scopus for article published after 2000, and after eliminating duplicates and non-relevant studies, we identified 13 studies. We combined their results with those of 31 non-overlapping studies included in a previous review up to 2000. We conducted a meta-analysis based on random-effects models. The pooled relative risk of kidney cancer for asbestos exposure was 0.94 (95% confidence interval, 0.84-1.04), with no differences according to type of asbestos fiber, geographic region, period of exposure, or estimated quality of the study. Our results showed a lack of association between occupational asbestos exposure and risk of kidney cancer.

Smoking-adjusted risk of kidney cancer by occupation: a population-based cohort study of Nordic men

Background: Evidence suggests that among some occupational groups, there is an elevated risk of kidney cancer. This might, however, derive from a difference in smoking habits across occupational groups. The objective of this study was to determine smoking-adjusted occupational variation in the incidence of kidney cancer in Nordic males.Material and Methods: The source population for this study consisted of 7.4 million men from Denmark, Iceland, Finland, Norway, and Sweden. Data on occupation were obtained from national censuses conducted in the years 1960-1990. Data on cancer cases came from national cancer registries. A proxy for the occupation-specific smoking prevalence among all Nordic men was calculated based on the occupation-specific smoking prevalence and lung cancer incidence data for Finnish men. Smoking-adjusted standardized incidence ratio (SIRadj) with 95% confidence intervals (95%CI) were calculated for each occupational group.Results: The highest SIRadj estimates were observed in dentists (1.32, 95%CI 1.06-1.62), journalists (1.20, 95%CI 1.00-1.42), physicians (1.19, 95%CI 1.03-1.36), public safety workers (1.18, 95%CI 1.10-1.26), administrators (1.17, 95%CI 1.13-1.22), military personnel (1.16, 95%CI 1.05-1.28), and religious workers (1.17, 95%CI 1.09-1.26). The lowest SIRadj was observed among forestry workers (0.82, 95%CI 0.76-0.88).Conclusions: Tobacco smoking plays an important role in the occupational variation in the risk of kidney cancer. The smoking-adjusted incidence of kidney cancer was increased in dentists, physicians, journalists, administrators, and public safety workers.

Formulation and characterization of EGCG for the treatment of superficial bladder cancer

In the United States, the annual incidence of bladder cancer is approximately 70,000 new cases, with a mortality rate of approximately 15,000/year. The most common subtype (70%) of bladder cancer is superficial, namely hte non-muscle invasive disease form limited to the urothelium. The rate of progression and recurrence is up to 40 and 70%, respectively. Urothelial cell carcinoma of the bladder is typically treated with transurethral resection. The cancerous cells can float onto the adjacent epithelium, increasing the risk of recurrence. The standard of care is to offer adjuvant intravesical agents to reduce the risk of progression and recurrence. Current intravesical treatments are costly and are associated with special biohazard handling protocols. Patients are treated with intravesical therapy with bacillus Calmetter-Guerin (BCG) bacterium, or mitomycin C (MMC) following resection, both of which can cause moderate to severe side-effects which are rarely life-threatening. We previously examined the efficacy of epigallocatechin-3-gallate (EGCG)in comparison with MMC to prevent tumor cell implantation/growth in an animal model of superficial bladder cancer. Experiments revile that EGCG is slightly more effective than MMC at decreasing tumor cell implantation and consequent cancer growth in a bladder. This treatment requires the stringent sterile requirement of EGCG. EGCG can be unstable when sterilized at high temperatures. Thus, we evaluated two low temperature sterilization methods, such as ionizing radiation or the filtration method followed by freeze-drying. Both methods ensure the sterility of the sample; however, infrared and HPLC analysis revealed a slightly better stability of irradiated EGCG over the filtration method. The concentration of stable free radicals following irradiation was low, which are unlikely to exert any damaging effects to EGCG. Therefore, we consider that radiation will be the preferred method of EGCG sterilization, and that this may prove useful for the effective use of EGCG in the treatment of bladder cancer.

Does occupational exposure to solvents and pesticides in association with glutathione S-transferase A1, M1, P1, and T1 polymorphisms increase the risk of bladder cancer? The Belgrade case-control study

OBJECTIVE

We investigated the role of the glutathione S-transferase A1, M1, P1 and T1 gene polymorphisms and potential effect modification by occupational exposure to different chemicals in Serbian bladder cancer male patients.

PATIENTS AND METHODS

A hospital-based case-control study of bladder cancer in men comprised 143 histologically confirmed cases and 114 age-matched male controls. Deletion polymorphism of glutathione S-transferase M1 and T1 was identified by polymerase chain reaction method. Single nucleotide polymorphism of glutathione S-transferase A1 and P1 was identified by restriction fragment length polymorphism method. As a measure of effect size, odds ratio (OR) with corresponding 95% confidence interval (95%CI) was calculated.

RESULTS

The glutathione S-transferase A1, T1 and P1 genotypes did not contribute independently toward the risk of bladder cancer, while the glutathione S-transferase M1-null genotype was overrepresented among cases (OR = 2.1, 95% CI = 1.1-4.2, p = 0.032). The most pronounced effect regarding occupational exposure to solvents and glutathione S-transferase genotype on bladder cancer risk was observed for the low activity glutathione S-transferase A1 genotype (OR = 9.2, 95% CI = 2.4-34.7, p = 0.001). The glutathione S-transferase M1-null genotype also enhanced the risk of bladder cancer among subjects exposed to solvents (OR = 6,5, 95% CI = 2.1-19.7, p = 0.001). The risk of bladder cancer development was 5.3-fold elevated among glutathione S-transferase T1-active patients exposed to solvents in comparison with glutathione S-transferase T1-active unexposed patients (95% CI = 1.9-15.1, p = 0.002). Moreover, men with glutathione S-transferase T1-active genotype exposed to pesticides exhibited 4.5 times higher risk in comparison with unexposed glutathione S-transferase T1-active subjects (95% CI = 0.9-22.5, p = 0.067).

CONCLUSION

Null or low-activity genotypes of the glutathione S-transferase A1, T1, and P1 did not contribute independently towards the risk of bladder cancer in males. However, in association with occupational exposure, low activity glutathione S-transferase A1 and glutathione S-transferase M1-null as well as glutathione S-transferase T1-active genotypes increase individual susceptibility to bladder cancer.

Use of the Finnish Information System on Occupational Exposure (FINJEM) in epidemiologic, surveillance, and other applications

This paper reviews the use of the Finnish Information System on Occupational Exposure (Finnish job-exposure matrix, FINJEM) in different applications in Finland and other countries. We describe and discuss studies on FINJEM and studies utilizing FINJEM in regard to the validity of exposure estimates, occupational epidemiology, hazard surveillance and prevention, the assessment of health risks and the burden of disease, the assessment of exposure trends and future hazards, and the construction of job-exposure matrices (JEMs) in countries other than Finland. FINJEM can be used as an exposure assessment tool in occupational epidemiology, particularly in large register-based studies. It also provides information for hazard surveillance at the national level. It is able to identify occupations with high average exposures to chemical agents and can therefore serve the priority setting of prevention. However, it has only limited use at the workplace level due to the variability of exposure between workplaces. The national estimates of exposure and their temporal trends may contribute to the assessment of both the recent and future burden of work-related health outcomes. FINJEM has also proved to be useful in the construction of other national JEMs, for example in the Nordic Occupational Cancer study in the Nordic countries. FINJEM is a quantitative JEM, which can serve many purposes and its comprehensive documentation also makes it potentially useful in countries other than Finland.

Safety assessment of isoparaffins as used in cosmetics

The safety of isoparaffins as used in cosmetic products is reviewed in this safety assessment. These ingredients function mostly as solvents and also function as emollients in the 0001% to 90% concentration range. The Cosmetic Ingredient Review (CIR) Expert Panel has reviewed relevant animal and clinical data and concluded that these ingredients are safe in the present practices of use and concentration described in this safety assessment.

Occupation and bladder cancer in a population-based case-control study in Northern New England

OBJECTIVES

We used data from a large, population-based case-control study in Maine, New Hampshire, and Vermont to examine relationships between occupation, industry and bladder cancer risk.

METHODS

Lifetime occupational histories were obtained by personal interview from 1158 patients newly diagnosed with urothelial carcinoma of the bladder in 2001-2004, and from 1402 population controls. Unconditional logistic regression was used to calculate ORs and 95% CIs, adjusted for demographic factors, smoking and employment in other high-risk occupations.

RESULTS

Male precision metalworkers and metalworking/plasticworking machine operators had significantly elevated risks and significant trends in risk with duration of employment (precision metalworkers: OR 2.2, 95% CI 1.4 to 3.4, p(trend) = 0.0065; metalworking/plasticworking machine operators: OR 1.6, 95% CI 1.01 to 2.6, p(trend) = 0.047). Other occupations/industries for which risk increased significantly with duration of employment included: for men, textile machine operators, mechanics/repairers, automobile mechanics, plumbers, computer systems analysts, information clerks, and landscape industry workers; for women, service occupations, health services, cleaning and building services, management-related occupations, electronic components manufacturing and transportation equipment manufacturing. Men reporting use of metalworking fluids (MWF) had a significantly elevated bladder cancer risk (OR 1.7, 95% CI 1.1 to 2.5).

CONCLUSIONS

Our findings support the hypothesis that some component(s) of MWF may be carcinogenic to the bladder. Our results also corroborate many other previously reported associations between bladder cancer risk and various occupations. More detailed analyses using information from the study's job-specific questionnaires may help to identify MWF components that may be carcinogenic, and other bladder carcinogens associated with a variety of occupations.

Epidemiologic characteristics and risk factors for renal cell cancer

Incidence rates of renal cell cancer, which accounts for 85% of kidney cancers, have been rising in the United States and in most European countries for several decades. Family history is associated with a two- to four-fold increase in risk, but the major forms of inherited predisposition together account for less than 4% of renal cell cancers. Cigarette smoking, obesity, and hypertension are the most consistently established risk factors. Analgesics have not been convincingly linked with renal cell cancer risk. A reduced risk of renal cell cancer among statin users has been hypothesized but has not been adequately studied. A possible protective effect of fruit and vegetable consumption is the only moderately consistently reported dietary finding, and, with the exception of a positive association with parity, evidence for a role of hormonal or reproductive factors in the etiology of renal cell cancer in humans is limited. A recent hypothesis that moderate levels of alcohol consumption may be protective for renal cell cancer is not strongly supported by epidemiologic results, which are inconsistent with respect to the categories of alcohol consumption and the amount of alcohol intake reportedly associated with decreased risk. For occupational factors, the weight of the evidence does not provide consistent support for the hypotheses that renal cell cancer may be caused by asbestos, gasoline, or trichloroethylene exposure. The established determinants of renal cell cancer, cigarette smoking, obesity, and hypertension, account for less than half of these cancers. Novel epidemiologic approaches, including evaluation of gene–environment interactions and epigenetic mechanisms of inherited and acquired increased risk, are needed to explain the increasing incidence of renal cell cancer.