INTRODUCTION: This study focus on the incidence of asbestos-related cancers among 28,300 officers and enlisted servicemen in the Royal Norwegian Navy. Until 1987, asbestos aboard the vessels potentially caused exposure to 11,500 crew members. METHODS: Standardized incidence ratios (SIR) were calculated for malignant mesothelioma, lung cancer, and laryngeal, pharyngeal, stomach, and colorectal cancers according to service aboard between 1950 and 1987 and in other Navy personnel. RESULTS: Increased risk of mesothelioma was seen among engine room crews, with SIRs of 6.23 (95% CI = 2.51-12.8) and 6.49 (95% CI = 2.11-15.1) for personnel who served less than 2 years and those with longer service, respectively. Lung cancer was nearly 20% higher than expected among both engine crews and non-engine crews. An excess of colorectal cancer bordering on statistical significance was seen among non-engine crews (SIR = 1.14; 95% CI = 0.98-1.32). Land-based personnel and personnel who served aboard after 1987 had lower lung cancer incidence than expected (SIR = 0.77; 95% CI = 0.64-0.92). No elevated risk of laryngeal, pharyngeal, or stomach cancers was seen. CONCLUSION: The overall increase (65%) in mesotheliomas among military Navy servicemen was confined to marine engine crews only. The mesothelioma incidence can be taken as an indicator of the presence or absence of asbestos exposure, but it offered no consistent explanation to the variation in incidence of other asbestos-related cancers.
Scandinavian moist snuff (snus) is claimed to be a safer alternative to smoking. We aimed to quantify cancer incidence among male snus users and to shed light on the net health outcome by studying their overall mortality. A cohort, comprised of 9,976 men who participated in a population-based survey, was compiled in 1973-74. Follow-up until January 31, 2002, was accomplished through record-linkages with nation-wide and essentially complete registers of demographics, cancer and causes of deaths. Adjusted relative risks among exposed relative to unexposed men were estimated using Cox proportional hazards regression. The cohort members contributed more than 220,000 person-years at risk for cancer. A statistically significant increase in the incidence of the combined category of oral and pharyngeal cancer among daily users of snus (incidence rate ratio 3.1, 95% confidence interval 1.5-6.6) was found. Overall mortality was also slightly increased (hazard ratio 1.10, 95% confidence interval 1.01-1.21). Although the combined previous literature on snus and oral cancer weigh toward no association, this population-based prospective study provided suggestive evidence of snus-related risks that cannot be lightly ignored.
An increased risk of cancer of the upper aerodigestive tract has been demonstrated among the members of the Danish Brewery Workers Union. To determine the role of tobacco, beer and strong liquors in the development of these cancers, a case-control study was conducted among those brewery workers who during the years 1943-1972 developed cancer of the pharynx (excluding nasopharynx), larynx, or esophagus. Controls were chosen among brewery workers who did not develop these cancers. Data concerning individual drinking and smoking habits were collected retrospectively from hospital records and by means of a mailed, self-administered questionnaire for patients or their relatives. An analysis based on the combined set of information from the two sources, showed an increased relative risk of developing an upper aerodigestive cancer, with increasing daily tobacco consumption. Likewise, we found an increasing relative risk with increasing daily alcohol consumption, statistically significant for oesophagus cancer and for all three cancer types as a whole. When looking at daily beer consumption alone, the same increased risk was found, but was only statistically significant for oesophagus cancer. No evidence of any particularly heavy consumption of strong alcoholic beverages was seen amongst the brewery workers as a whole or amongst the cases. Thus, the study supports the hypothesis that heavy beer intake may be a risk factor in the development of upper aerodigestive cancer.
In an international collaboration, cancers of the buccal cavity and pharynx were combined from cancer registries in the Circumpolar region, including Alaska, Canada and Greenland. Low risk of cancers of the lip (SIR 0.2) was observed among Inuit. Increased risk of cancer of the tongue and oral cancer (SIR 2.5) were observed among Greenlandic Inuit men. Salivary gland cancer and nasopharyngeal cancer occur among Inuit with rates among the highest in the world. Environmental factors (EBV, diet) and a genetically susceptible population are believed to play a role.
Social status and occupation-specific risks of cancers of the lip, tongue, mouth and pharynx were studied in a nationwide series of 2369 men and 809 women diagnosed in Finland in 1971-1985 and recorded in the files of the Finnish Cancer Registry. Codes for social status (four classes) and occupation (336 categories) were drawn from the files of the 1970 Population Census. The standardised incidence rates (SIR) were defined as the ratios of observed and expected numbers of cases, the expected ones being based on the sex, age, site and calendar period-specific incidence rates in the Finnish population. The SIR of lip cancer in the lowest social class was five times that of the highest one, thus indicating the effects of social class differences in smoking habits. The effect of outdoor work on the development of lip cancer was also strongly supported by this study. The social class-adjusted SIR for fisherman was 2.7 (95% C.I. 1.3-5.0), for forestry managers 2.2 (1.2-3.6), for timber workers 1.9 (1.2-2.9) and for farmers 1.8 (1.2-2.6). For cancers of the oral cavity and pharynx there was no clear correlation with social class. However, the SIR for these cancers among farmers was significantly reduced. The occupation-specific SIRs pointed more to alcohol than smoking aetiology. In the case of cancer of the tongue, no aetiological clues whatsoever could be found. The role of direct occupational factors in the aetiology of any of these cancers seemed to be minimal.