Occupation and prostate cancer risk in Sweden

To provide new leads regarding occupational prostate cancer risk factors, we linked 36,269 prostate cancer cases reported to the Swedish National Cancer Registry during 1961 to 1979 with employment information from the 1960 National Census. Standardized incidence ratios for prostate cancer, within major (1-digit), general (2-digit), and specific (3-digit) industries and occupations, were calculated. Significant excess risks were seen for agriculture-related industries, soap and perfume manufacture, and leather processing industries. Significantly elevated standardized incidence ratios were also seen for the following occupations: farmers, leather workers, and white-collar occupations. Our results suggest that farmers; certain occupations and industries with exposures to cadmium, herbicides, and fertilizers; and men with low occupational physical activity levels have elevated prostate cancer risks. Further research is needed to confirm these findings and identify specific exposures related to excess risk in these occupations and industries.     

Occupation, cadmium exposure, and prostate cancer

A population-based case-control study was used to investigate associations between prostate cancer and cadmium exposure, longest industry held, and longest occupation held. The study included 358 men with newly diagnosed prostate cancer and 679 control men identified from the Utah population. Occupational exposures to cadmium were ascertained from self-reported data, through several a priori suspect industries and occupations, through an occupation-exposure linkage system, and through dietary food frequency questionnaires. Overall, cadmium exposure appeared to result in a small increased relative risk for prostate cancer, most apparent for aggressive tumors (OR = 1.7, CI = 1.0-3.1 for any occupational exposure, high dietary intake, or smoking cigarettes). Cases were more likely to have worked in the following industries: mining, paper and wood, medicine and science, and entertainment and recreation. Among men younger than 67, cases were also more likely to have worked in the food and tobacco industries (OR = 3.6, CI = 1.0-12.8). Cases were less likely to have worked in industries involved with glass, clay and stone, or rubber, plastics, and synthetics. Men employed as janitors and in other building service occupations showed increased relative risk for aggressive tumors (OR = 7.0, CI = 2.5-19.6). Agricultural occupations did not appear to be related to prostate cancer, although an increased relative risk for aggressive tumors was detected among younger men (OR = 2.6, CI = 0.6-12.1).     

Occupation related pesticide exposure and cancer of the prostate: a meta-analysis

Aims: To summarise recent literature on the risk of prostate cancer in pesticide related occupations, to calculate the meta-rate ratio, and to compare it to data from meta-analyses previously published.

Methods: A meta-analysis of 22 epidemiological studies, published between 1995 and 2001, was conducted in order to pool their rate ratio estimates. Studies were summarised and evaluated for homogeneity and publication bias.

Results: The meta-rate ratio estimate, based on 25 estimators of relative risk from 22 studies, was 1.13 (95% CI 1.04 to 1.22). Significant heterogeneity of rate ratios existed among the different studies. Therefore, a stratified analysis was carried out. Major sources of heterogeneity identified were geographic location, study design, and healthy worker effect. Overall, pooled risk estimates for studies derived from Europe were lower than those derived from the USA/Canada. A significant increase in rate ratio was observed for the occupation category of pesticide applicators, whereas no significant increase was observed for farmers. There was no evidence of publication bias.

Conclusion: This increased meta-rate ratio for prostate cancer in different pesticide related occupations, including farmers, is very similar to three, previously published, meta-rate ratios for prostate cancer in farmers calculated from studies published before 1995. Although the underlying data do not identify pesticide exposure as an independent cause for prostate cancer, the fact that an increased meta-rate ratio is again obtained points to occupational exposure to pesticides as a possible factor. Future epidemiological studies should focus, as far as possible, on reliable methods to estimate actual exposure.

     

Occupation and the occurrence of testicular cancer.

To investigate what role a man's occupation may have on his risk of testicular cancer, we conducted a case-control study among noncryptorchid white males who were between 20 and 69 years of age and resided in western Washington State. Cases were men in whom a germ cell tumor of the testis was diagnosed between 1977 and 1984 (n = 323). Their occupational histories were compared to those of controls of the same age, race, and geographic area who were selected through random-digit dialing (n = 658). Administrators/managers (relative risk (RR) = 1.5), salesmen (RR = 1.5), electricians (RR = 2.8), and sailors and fishermen (RR = 3.1) were among the jobs reported more commonly by cases than controls. The risk among farmers/farm managers was also elevated (RR = 1.9), but not that among farm workers (RR = 0.6). No consistent association between any one occupation and testicular cancer has been observed across studies of this topic. The most frequent observation has been an over-representation among cases of certain types of white collar worker; this may reflect the influence of some other aspect of socioeconomic status and not occupational exposures per se.     

Occupation and bladder cancer risk.

This study examines the estimated risk of bladder cancer associated with various occupations among 1,465 cases identified in Orange County, California, during 1984-1988. The annual age-adjusted incidence rate per 100,000 population in Orange County was similar to that of the Surveillance, Epidemiology, and End Results Program of the National Cancer Institute: 25.7 in males and 6.2 in females. Cases were compared with a sample of Orange County residents relative to broad category of current occupation, adjusted for age and cigarette smoking. The estimated relative risks were significant for males in machine trades (relative risk (RR) = 2.69, 95% confidence interval (CI) 1.24-5.82) and processing occupations (RR = 5.77, 95% CI 1.43-23.27) and for females in machine trades (RR = 8.34, 95% CI 1.14-61.17) and homemakers (RR = 5.37, 95% CI 2.40-11.99) as compared with individuals of the same sex in professional, technical, and managerial occupations.     

Occupation and the risk of bladder cancer

The relationship between bladder cancer, occupation and exposure to a number of occupational agents was assessed in a case-control study conducted in the greater Milan area, Northern Italy. The case series consisted of 263 cases (219 males, 44 females) with histologically confirmed invasive bladder cancer, admitted to a network including major teaching and general hospitals in the area under surveillance. The controls were 287 patients (210 males, 77 females), admitted for acute, non-neoplastic or urinary tract diseases to the same network of hospitals. Cases more frequently reported occupation in dyestuff production (relative risk (RR) = 4.6), painting/spraying work (RR = 1.8), chemical industry (RR = 1.7), pharmaceuticals (RR = 1.7) and coal/gas production (RR = 3.1). Only for dyestuff production however, was the excess statistically significant. There was no association with agriculture or related activities, rubber manufacturing, printing, the petroleum industry, food processing and mechanics. In relation to exposure to occupational agents, significant positive trends in risk were observed for dyes/paints (RR = 4.8 for greater than ten years of exposure), herbicides (RR = 4.1), chemicals (RR = 2.4) and gases/fumes (RR = 4.8). No association was found with metals or metal dusts, plastic resins or glues, oil, wood dust, solvents or benzene, asbestos, electricity or radar and coal tar. Besides confirming the well known association between bladder cancer risk and dyestuff production and, to a lesser extent, a wide spectrum of chemical-related activities, this study provides statistically significant evidence of an independent role of herbicides on the risk of bladder cancer.(ABSTRACT TRUNCATED AT 250 WORDS)     

Vasectomy and the risk of prostate cancer.

Even if there is a weak association between vasectomy and subsequent prostate cancer, we believe that large-scale studies on this question should be of low priority in developing countries where vasectomy is widely practised and where the incidence of prostate cancer is low. Arguments to justify this point of view are presented.     

Occupation, smoking, and alcohol in the epidemiology of bladder cancer.

We conducted a case-control study to evaluate the effects of occupation, smoking, and alcohol consumption on bladder cancer risk. A total of 823 male cases and 2,469 age-matched controls were identified through the Missouri Cancer Registry. Relative risk estimates of 2.0 or greater were observed for janitors and cleaners, mechanics, miners, and printers. Current cigarette smoking was associated with a two-fold excess risk of bladder cancer, whereas alcohol consumption showed no association with bladder cancer risk.     

Occupation and lung cancer in nonsmokers

Lung cancer remains a significant burden on society, with approximately 157,200 deaths from this disease in 2003 occurring in the United States alone. Smoking causes the vast majority of cases (and deaths) from lung cancer, occupation may account for as many as 16,700 of such deaths. To examine the influence of occupation independent of smoking, we reviewed the literature on occupational lung cancer in nonsmokers. We found that most individual studies and summaries of occupational lung cancer are based on data having a heavy preponderance of male smokers. Relatively little data are available concerning females and nonsmokers. Specific dose-response information is often lacking. Although many studies have been adjusted for smoking, there remains a significant potential for residual confounding because of the overwhelming importance of smoking in the etiology of this disease. Our review has found some evidence that asbestos, environmental tobacco smoke, and radon decay products (progeny) are occupational carcinogens in nonsmokers. Increased risk for lung cancer might also occur in nonsmokers from occupational exposure to arsenic. Nevertheless, for many agents and occupations occupations or industries listed in the database of the International Agency for Research on Cancer (IARC), we could not locate any study that found them to be occupational risk factors for lung cancer in nonsmokers. Thus, considerable uncertainty exists about their ability to cause lung cancer in the nonsmoking working population. We discuss problems with the original occupational studies and the IARC list of carcinogens. Besides the absence of information on nonsmokers, these problems include lack of sufficient detail on exposure to the primary agent of concern and to other occupational lung carcinogens. Further research on occupational causes of lung cancer in nonsmokers should be given high priority.     

Occupation and gastric cancer in Spain

The association between occupational exposure and stomach cancer was investigated in a multicenter case-referent study conducted in Spain on 354 histologically confirmed cases and 354 hospital referents, matched by age, gender, and residence. An increased risk of gastric cancer was found for coal mining workers [odds ratio (OR) 11.8], but the number of workers was small, and therefore the 95% confidence interval (95% CI) was wide (95% CI 1.36-103). An increased risk was observed for wood and furniture workers (OR 1.76), construction workers (OR 1.68), and glass and ceramic workers (OR 2.18), but none of these risks were statistically significant. According to an occupation-exposure linkage system an increased risk was found for occupations associated with exposure to silica and mineral dust (OR 1.80, 95% CI 0.90-3.59). All of the OR estimates were adjusted for the confounding factors socioprofessional status and dietary habits. The possibility of a causal association between stomach cancer and coal and mineral dust is supported by the results.     

Occupation and the risk of laryngeal cancer in Uruguay

In a case-control analysis involving 112 patients afflicted by laryngeal cancer and 509 controls diagnosed with cancers not related to tobacco and alcohol exposures, we studied the effects of type of employment and of substances present in the workplace on laryngeal cancer risk. Effects were measured relative to those never employed or never exposed to the substances. All analyses were controlled for age, tobacco smoking, and alcohol drinking through unconditional logistic regression and stratified analysis. Among job titles, butchers, vintners, bakers, and car assemblers presented elevated risks of laryngeal cancer (OR for butchers 2.8, 95% CL 1.1–7.2). Similarly, asbestos, mists from strong inorganic acids and pesticide exposures were associated with increased risks of laryngeal cancer (OR for strong acids 1.8, 95% 1.1–2.9). Am. J. Ind. Med. 33:537–542, 1998. © 1998 Wiley-Liss, Inc.     

Occupation and bladder cancer in Utah

The relationships between bladder cancer and occupation, industries, and occupational exposures in Utah were examined in a population-based, case-control study conducted between 1977 and 1983. Life-long occupational histories were obtained for 417 cases (332 men and 85 women) and 877 controls (685 men and 192 women). Although few positive findings emerged in this study, increased risks were detected among men for employment in the leather and textile industries which increased with duration of employment. The effects were most marked for employment beginning 45 or more years prior to interview (odds ratio [OR] for textiles = 1.92, confidence interval [CI] = 0.89-4.46; for leather OR = 2.95, CI = 0.63-13.76). Among men and women, increased risk was detected among clerical workers employed for less than 10 years (OR = 1.59, CI = 1.16-2.17) although the risk decreased with increased duration of employment (OR = 0.88, CI = 0.55-1.40 for greater than or equal to 10 years). A protective effect was seen among men and women for 10 or more years employment in professional, managerial, and technical occupations (OR = 0.68, CI = 0.50-0.92). Employment as a carpenter resulted in increased risk which increased with duration. Increased risk for bladder cancer was detected among carpenters who smoked but not among carpenters who never smoked. We used an occupation-exposure linkage system to identify workers exposed to aromatic amino compounds; such workers did not have increased risk of bladder cancer, although interaction between long-term exposure to aromatic amino compounds and smoking was detected. Interactions between smoking and other industrial or occupational exposures were not demonstrated, and for the most part, smoking did not confound the estimates of the bladder cancer-occupation relationships.     

Occupation and the risk of laryngeal cancer in Turkey

OBJECTIVES: A hospital-based case-referent study was conducted in Turkey to provide further information on occupational risk factors and laryngeal cancer. METHODS: Among 7631 cancer cases seen at an oncology treatment center between 1979 and 1984, 958 laryngeal cancer cases were identified among men. Occupational history, tobacco and alcohol use, and demographic data were obtained from patients with a standardized questionnaire. Special 7-digit standard occupational and industrial codes were created to classify the job and industrial titles of the subjects. After exclusions, 940 laryngeal cancer cases and 1519 referents were available for study. Age-, smoking- and alcohol-adjusted odds ratios (OR) and 95% confidence intervals (95% CI) were calculated. RESULTS: Excess laryngeal cancer occurred among guards (OR 1.5, 95% CI 1.1-2.1), production supervisors (OR 1.8, 95% CI 1.1-3.1), textile workers (OR 1.9, 95% CI 1.2-3.3), drivers (OR 1.7, 95% CI 1.1-2.4), construction workers (OR 1.7, 95% Cl 1.2-2.6), and workers in grain mills (OR 3.1, 95% CI: 1.3-7.6), trade unions (OR 3.6, 95% CI: 1.1-11.7) and local government services (OR 4.7, 95% CI 1.7-12.5). Supraglottic cancer was excessive among the textile workers, construction workers, and local government laborers, all with potential dust exposure. The risks of the general managers, electricians, and workers from industries such as pharmaceutical production, industrial machinery production, electric utilities, and retail services were lower than expected. CONCLUSIONS: The risk of laryngeal cancer was associated with several occupations, and supraglottic larynx cancer appears to be more common among workers in dusty occupations and industries.     

Occupation as a risk identifier for breast cancer.

OBJECTIVES. Breast cancer mortality may be reduced if the disease is detected early through targeted screening programs. Current screening guidelines are based solely on a woman's age. Because working populations are accessible for intervention, occupational identification may be a way of helping to define and locate risk groups and target prevention. METHODS. We used a database consisting of 2.9 million occupationally coded death certificates collected from 23 states between 1979 and 1987 to calculate age-adjusted, race-specific proportionate mortality ratios for breast cancer according to occupation. We performed case-control analyses on occupational groups and on stratifications within the teaching profession. RESULTS. We found a number of significant associations between occupation and frequency of breast cancer. For example, white female professional, managerial, and clerical workers all had high proportions of breast cancer death. High rates of breast cancer in teachers were found in both proportionate mortality ratio and case-control analyses. CONCLUSIONS. These findings may serve as in an aid in the effective targeting of work-site health promotion programs. They suggest that occupationally coded mortality data can be a useful adjunct in the difficult task of identifying groups at risk of preventable disease.     

Sexual factors and the risk of prostate cancer.

A population-based case-control study of prostate cancer was performed in King County, Washington, in White men and Black men aged 40-64 years, between 1993 and 1996. Incident prostate cancer cases (n = 753) were identified from the Seattle-Puget Sound Surveillance, Epidemiology, and End Results (SEER) cancer registry. Controls (n = 703) were identified through random digit dialing and were frequency matched to cases on age. Sexual behavior, medical history, and other potential prostate cancer risk factors were ascertained through an in-person interview. There was no relation between sexual orientation and prostate cancer, although the number of men who had sex with men was small. Risk estimates increased directly with the lifetime number of female sexual partners (trend p < 0.001) but not with male partners (trend p = 0.62). Risk also increased with decreasing age at first intercourse, but this effect disappeared after adjusting for the number of female partners. Prior infection with gonorrhea was positively associated with risk (odds ratio = 1.50; 95% confidence interval: 1.0, 2.2), but no effect was seen among men with other sexually transmitted diseases. No relation between lifetime frequency of sexual intercourse and risk of prostate cancer was apparent. These findings are consistent with previous studies that support an infectious etiology for prostate cancer.