Objective: To find associations between testicular cancer, occupation and chemical exposure.
Methods: A cohort of all economically active Finnish men born between 1906 and 1945 was followed-up for 19.7 million person-years during 1971-1995. Incident cases of testicular cancer (n=387) were identified in a record linkage with the Finnish Cancer Registry. The Census occupations in 1970 were converted to chemical exposures with a job-exposure matrix (FINJEM). Cumulative exposure (CE) was calculated as the product of prevalence, level, and duration of the exposure. Standardised incidence ratio (SIR) was calculated for each of the 393 occupations, and for CE categories of the 43 chemical agents, using average male population as reference. Relative risks (RR) comparing various CE-categories with unexposed ones were defined for selected agents by Poisson regression analysis.
Results: Elevated SIRs were observed among railway traffic supervisors (5.8, 95% CI 1.6-14.7), programmers (4.3, 1.4-9.9), university teachers (4.1, 1.3-9.5) and electrical engineers (3.9, 1.1-10.1). A significant exposure-response trend (mainly contributed by seminoma) was observed for pesticides, textile dust, aliphatic and alicyclic hydrocarbons, and some other organic solvents.
Conclusions: Risk of testicular cancer increased only in four occupations. Pesticides, textile dust, and some organic solvents may be related to an excess risk of seminoma.