Occupation, industry, and the risk of prostate cancer: a case-control study in Montréal, Canada

BACKGROUND: Age, family history and ancestry are the only recognized risk factors for prostate cancer (PCa) but a role for environmental factors is suspected. Due to the lack of knowledge on the etiological factors for PCa, studies that are both hypothesis-generating and confirmatory are still needed. This study explores relationships between employment, by occupation and industry, and PCa risk. METHODS: Cases were 1937 men aged ≤75 years with incident PCa diagnosed across Montreal French hospitals in 2005-2009. Controls were 1994 men recruited concurrently from electoral lists of French-speaking Montreal residents, frequency-matched to cases by age. In-person interviews elicited occupational histories. Unconditional logistic regression estimated odds ratios (OR) and 95 % confidence intervals (CI) for the association between employment across 696 occupations and 613 industries and PCa risk, adjusting for potential confounders. Multinomial logistic models assessed risks by PCa grade. Semi-Bayes (SB) adjustment accounted for the large number of associations evaluated. RESULTS: Consistently positive associations—and generally robust to SB adjustment—were found for occupations in forestry and logging (OR 1.9, 95 % CI: 1.2–3.0), social sciences (OR 1.6, 95 % CI: 1.1–2.2) and for police officers and detectives (OR: 1.8, 95 % CI 1.1–2.9). Occupations where elevated risk of high grade PCa was found included gasoline station attendants (OR 4.3, 95 % CI 1.8–10.4) and textile processing occupations (OR 1.8, 95 % CI 1.1–3.2). Aside from logging, industries with elevated PCa risk included provincial government and financial institutions. Occupations with reduced risk included farmers (OR 0.6, 95 % CI 0.4–1.0) and aircraft maintenance workers (OR 0.1, 95 % CI 0.0–0.7). CONCLUSIONS: Excess PCa risks were observed across several occupations, including predominantly white collar workers. Further analyses will focus on specific occupational exposures. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12940-016-0185-1) contains supplementary material, which is available to authorized users.