0084†A Case-Control Study of Occupational Exposure to Metalworking Fluids and Bladder Cancer Risk among Men.

OBJECTIVES: Metalworking has been associated with bladder cancer risk in many studies. Metalworking fluids (MWFs) are suspected as the putative exposure, but epidemiologic data are limited. Based on state-of-the-art, quantitative exposure assessment, we examined MWF exposure and bladder cancer risk in the New England Bladder Cancer Study. METHOD: Male cases (n = 895) and population controls (n = 1031) provided occupational histories and information on use of each of three MWF types: (1) straight (mineral oil, additives), (2) soluble (mineral oil, water, additives), and (3) synthetic (water, organics, additives) or semi-synthetic (soluble/synthetic hybrid), in response to exposure-oriented modules administered during personal interviews. We estimated the probability, frequency, and intensity of exposure to each MWF type and, if probability exceeded 50%, cumulative exposure. Logistic regression was used to calculate odds ratios (ORs) and 95% confidence intervals (CIs), adjusting for smoking and other risk factors. RESULTS: Risk was increased for men reporting use of straight MWFs (OR=1.7, 95% CI=1.1-2.8), with a significant trend with increasing cumulative exposure (p = 0.024). Use of soluble MWFs conferred a 50% elevated risk (95% CI=0.96-2.5). ORs were nonsignificantly elevated for synthetic MWFs, based on small numbers. Men who were never metalworkers, but held jobs with possible exposure to mineral oil, had a 40% increased risk (95% CI=1.1-1.8). CONCLUSIONS: In the most comprehensive assessment of MWF exposure in a bladder cancer case-control study, exposure to straight MWFs significantly increased bladder cancer risk, as did employment in non-metalworking jobs with possible mineral oil exposure. Our results strengthen prior evidence for mineral oil as a bladder carcinogen.

A case-control study of occupational exposure to metalworking fluids and bladder cancer risk among men.

OBJECTIVES: Metalworking has been associated with an excess risk of bladder cancer in over 20 studies. Metalworking fluids (MWFs) are suspected as the responsible exposure, but epidemiological data are limited. We investigated this association among men in the New England Bladder Cancer Study using state-of-the-art, quantitative exposure assessment methods. METHODS: Cases (n=895) and population controls (n=1031) provided occupational histories during personal interviews. For selected jobs, exposure-oriented modules were administered to collect information on use of three MWF types: (1) straight (mineral oil, additives), (2) soluble (mineral oil, water, additives) and (3) synthetic (water, organics, additives) or semisynthetic (hybrid of soluble and synthetic). We computed ORs and 95% CIs relating bladder cancer risk to a variety of exposure metrics, adjusting for smoking and other factors. Non-metalworkers who had held jobs with possible exposure to mineral oil were analysed separately. RESULTS: Bladder cancer risk was elevated among men who reported using straight MWFs (OR=1.7, 95% CI 1.1 to 2.8); risk increased monotonically with increasing cumulative exposure (p=0.041). Use of soluble MWFs was associated with a 50% increased risk (95% CI 0.96 to 2.5). ORs were non-significantly elevated for synthetic/semisynthetic MWFs based on a small number of exposed men. Non-metalworkers holding jobs with possible exposure to mineral oil had a 40% increased risk (95% CI 1.1 to 1.8). CONCLUSIONS: Exposure to straight MWFs was associated with a significantly increased bladder cancer risk, as was employment in non-metalworking jobs with possible exposure to mineral oil. These findings strengthen prior evidence for mineral oil as a bladder carcinogen.

Comparison of two expert-based assessments of diesel exhaust exposure in a case-control study: programmable decision rules versus expert review of individual jobs.

OBJECTIVES: Professional judgment is necessary to assess occupational exposure in population-based case-control studies; however, the assessments lack transparency and are time-consuming to perform. To improve transparency and efficiency, we systematically applied decision rules to questionnaire responses to assess diesel exhaust exposure in the population-based case-control New England Bladder Cancer Study. METHODS: 2631 participants reported 14 983 jobs; 2749 jobs were administered questionnaires ('modules') with diesel-relevant questions. We applied decision rules to assign exposure metrics based either on the occupational history (OH) responses (OH estimates) or on the module responses (module estimates); we then combined the separate OH and module estimates (OH/module estimates). Each job was also reviewed individually to assign exposure (one-by-one review estimates). We evaluated the agreement between the OH, OH/module and one-by-one review estimates. RESULTS: The proportion of exposed jobs was 20-25% for all jobs, depending on approach, and 54-60% for jobs with diesel-relevant modules. The OH/module and one-by-one review estimates had moderately high agreement for all jobs (κ(w)=0.68-0.81) and for jobs with diesel-relevant modules (κ(w)=0.62-0.78) for the probability, intensity and frequency metrics. For exposed subjects, the Spearman correlation statistic was 0.72 between the cumulative OH/module and one-by-one review estimates. CONCLUSIONS: The agreement seen here may represent an upper level of agreement because the algorithm and one-by-one review estimates were not fully independent. This study shows that applying decision-based rules can reproduce a one-by-one review, increase transparency and efficiency, and provide a mechanism to replicate exposure decisions in other studies.

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.

Oncology care in rural northern new England.

PURPOSE: A team from Maine, New Hampshire, and Vermont evaluated quality of care for breast and colon cancers in these predominantly rural states. METHODS: Central cancer registry records from diagnosis years 2003 to 2004 in Maine, New Hampshire, and Vermont were aggregated. Patient residence was classified into three tiers (small rural, large rural, and urban) using Rural-Urban Commuting Area classification. RESULTS: Among 6,134 women diagnosed with breast cancer, there were significant differences between rural and urban residents in age (P < .001), stage (P < .001), and tumor size (P = .006). Use of breast-conserving surgery was similar, but sentinel lymph node (SLN) dissection was more common in urban (44.1%) than in large rural (39.9%) and small rural (37.6%) areas. Patients who underwent SLN dissection were more likely to receive radiation therapy after lumpectomy than patients who underwent regional lymph node dissection without SLN (85.9% v 75.5%). However, there was no statistically significant association between the rates of postlumpectomy radiation therapy by residence. Among 2,848 patients with colon cancer, patient characteristics in rural and urban areas were similar, but there were differences in their subsequent surgical treatment (P < .001) and lymph node sampling (P = .079). Adjuvant chemotherapy for patients with stage III colon cancer was less frequent in rural (57.3%) than in urban areas (64.7%; P < .001). CONCLUSION: Central cancer registry data, aggregated among three states, identified differences between rural and urban areas in care for patients with breast and colon cancers. To our knowledge, this is the first time residential category, cancer stage, and treatment data have been analyzed for multiple states using population-based data.

A case-control study of smoking and bladder cancer risk: emergent patterns over time.

BACKGROUND: Cigarette smoking is a well-established risk factor for bladder cancer. The effects of smoking duration, intensity (cigarettes per day), and total exposure (pack-years); smoking cessation; exposure to environmental tobacco smoke; and changes in the composition of tobacco and cigarette design over time on risk of bladder cancer are unclear. METHODS: We examined bladder cancer risk in relation to smoking practices based on interview data from a large, population-based case-control study conducted in Maine, New Hampshire, and Vermont from 2001 to 2004 (N = 1170 urothelial carcinoma case patients and 1413 control subjects). We calculated odds ratios (ORs) and 95% confidence intervals (CIs) using unconditional logistic regression. To examine changes in smoking-induced bladder cancer risk over time, we compared odds ratios from New Hampshire residents in this study (305 case patients and 335 control subjects) with those from two case-control studies conducted in New Hampshire in 1994-1998 and in 1998-2001 (843 case patients and 1183 control subjects). RESULTS: Regular and current cigarette smokers had higher risks of bladder cancer than never-smokers (for regular smokers, OR = 3.0, 95% CI = 2.4 to 3.6; for current smokers, OR = 5.2, 95% CI = 4.0 to 6.6). In New Hampshire, there was a statistically significant increasing trend in smoking-related bladder cancer risk over three consecutive periods (1994-1998, 1998-2001, and 2002-2004) among former smokers (OR = 1.4, 95% CI = 1.0 to 2.0; OR = 2.0, 95% CI = 1.4 to 2.9; and OR = 2.6, 95% CI = 1.7 to 4.0, respectively) and current smokers (OR = 2.9, 95% CI = 2.0 to 4.2; OR = 4.2, 95% CI = 2.8 to 6.3; OR = 5.5, 95% CI = 3.5 to 8.9, respectively) (P for homogeneity of trends over time periods = .04). We also observed that within categories of intensity, odds ratios increased approximately linearly with increasing pack-years smoked, but the slope of the increasing trend declined with increasing intensity. CONCLUSIONS: Smoking-related risks of bladder cancer appear to have increased in New Hampshire since the mid-1990s. Based on our modeling of pack-years and intensity, smoking fewer cigarettes over a long time appears more harmful than smoking more cigarettes over a shorter time, for equal total pack-years of cigarettes smoked.