[Epidemiological investigation on bladder cancer and occupations].

A population-based case-control study was conducted in Boston, U.S.A., Manchester, U.K., and Nagoya, Japan to assess the associations of occupations with bladder cancer in men. In Nagoya, cancer cases were identified through Nagoya Bladder Cancer Registry, and controls were randomly selected from the general population using electoral registers. Study subjects, all males, analyzed were 430 cases and 397 controls in Boston; 339 and 493 in Manchester, and 220 and 443 in Nagoya, respectively. Occupations significantly related to an increased bladder cancer risk were those manufacturing or handling dyes, leather, paint or organic chemicals in Boston, and leather or medical workers in Manchester. Occupations significantly associated with bladder cancer development were not found in Nagoya. In general, risk related to occupations was relatively higher in the younger age group (less than 65 years old) than in the older age group (greater than or equal to 65 yrs old). Statistically significant differences in bladder cancer risk were not demonstrated between manufacturing workers and service workers.