Occupation and larynx and hypopharynx cancer: an international case-control study in France, Italy, Spain, and Switzerland.

OBJECTIVE: To estimate risks for laryngeal/hypopharyngeal cancer associated with occupational titles and industrial activities. METHODS: A multicentre population-based case-control study was conducted in the early 1980s in six southern European areas. Analyses included 1010 male cases and 2176 controls. Odds ratios (ORs) (adjusted for age, study area, tobacco consumption, and alcohol consumption) were estimated for 156 occupations and 70 industrial activities. RESULTS: An excess risk has been confirmed for categories of construction workers, potters (OR: 5.91, 95% confidence intervals 1.46-24.0), butchers (2.53, 1.22-5.22), barbers (2.33, 1.00-5.40), laborers not otherwise specified (1.52, 1.12-2.06), as well as for men who had been employed in railway transport (1.52, 0.97-2.39), shipbuilding (2.05, 0.89-4.94), and hotels (2.06, 0.89-4.75). An association was also found for shoe finishers (3.23, 0.75-13.9), loggers (2.07, 0.87-4.90), and some groups of metal workers. ORs for loggers, butchers, railway transport workers, laborers, and reinforced concreters increased with duration of employment. The suggestion of a risk for machine operators among woodworkers (3.10, 0.92-10.5) conflicts with previous findings. No significant excess of risk was found for categories previously reported to be associated with laryngeal and hypopharyngeal cancer, such as drivers, mechanics, welders, machinists, and painters. CONCLUSIONS: The present study provides additional evidence to the hypothesis of a risk of cancer of the larynx/ hypopharynx for workers engaged in jobs in the construction, metal, textile, ceramic, and food industries and in railway transport. Loggers were also found at risk; a previously unreported finding.

Occupation and larynx and hypopharynx cancer: a job-exposure matrix approach in an international case-control study in France, Italy, Spain and Switzerland.

OBJECTIVE: To investigate the effect of exposure to occupational agents on the risk of hypopharyngeal/laryngeal cancer. METHODS: Case-control study conducted during 1979-1982 in six centres in South Europe. An occupational history and information on exposure to non-occupational factors were collected for 1010 male cases of hypopharyngeal/ laryngeal cancer as well as for 2176 population controls. The exposure to 10 occupational agents was assessed through a job-exposure matrix. As occupational histories had been collected since 1945 major analyses were restricted to subjects aged less than 55 years (315 cases and 819 controls). RESULTS: Significant elevated risks adjusted for non-occupational variables (smoking, alcohol consumption and diet) and other occupational exposures were consistently found for organic solvents (odds ratio (OR) for ever-exposure: 1.7, 95% confidence interval: 1.1-2.5) and asbestos (OR: 1.6, 1.0-2.5). A significant positive trend for both probability of exposure and duration was found for exposure to solvents. A positive association between exposure to formaldehyde and laryngeal cancer was also suggested. No association was found for exposure to arsenic and compounds, chromium and compounds, and polycyclic aromatic hydrocarbons. Analyses restricted to subjects aged 55 or more did not show elevated risks, with the exception of wood dust (OR: 1.8, 1.3-2.7). CONCLUSIONS: In our study occupational exposure to solvents was associated with an increased risk of hypopharyngeal/laryngeal cancer. Results also provide additional evidence of an excess of risk for exposure to asbestos.