Objectives To report on the association between pesticides exposure and prostate cancer (PC) risk from PROTEuS (Prostate Cancer & Environment Study), a case-control study on-going in Montreal.

Methods Incident, histologically confirmed cases aged ≤75 were ascertained across major hospitals in Greater Montreal. Population controls from the same area, frequency-matched on age, were identified from electoral lists. This analysis is based on the first 820 cases and 661 controls interviewed to date. Subjects provided a detailed description of each job held over their lifetime; potential exposure to pesticides was assigned using the expert-based approach. Use of domestic pesticides was elicited. ORs and 95% CI were assessed, adjusting for age, family history of PC, body mass index and ethnicity.

Results Exposure to pesticides was often seasonal. Pesticides exposure was most often assigned to farmers, carpenters and cooks. The OR for men with probable or definite occupational exposure to pesticides was 0.79 (95% CI 0.51 to 1.22). Domestic exposure to pesticides was associated with an OR of 0.83 (95% CI 0.66 to 1.05). Regular golfers had an OR of 0.75 (95% CI 0.59 to 0.96). Restricting analyses to controls who reported recent PC screening, or to cases with aggressive PC, yielded similar results.

Conclusions We observed no association between pesticides exposure and PC cancer risk. However, the prevalence of exposure to pesticides was low (7%), limiting the ability to detect associations. As the study progresses towards its aim of 2000 cases and 2000 controls, results will be updated.