Article Text
Abstract
Objectives Prostate cancer continues to be the most commonly diagnosed cancer in North American men. There are few established risk factors and there is limited evidence on occupational risk factors for prostate cancer. The purpose of this study was to investigate the relationship between employment in specific industries and occupations and prostate cancer risk.
Methods Data were used from the National Enhanced Cancer Surveillance System case-control study that was conducted in eight Canadian provinces. Between 1994 and 1997, mailed questionnaires were used to collect information on potential risk factors for cancer including lifetime occupational history. This analysis included 1737 prostate cancer cases and 1803 controls aged 50 to 79 years. Lifetime occupational histories were used to characterise associations between specific jobs and prostate cancer. Odds ratios and 95% confidence intervals were generated using logistic regression.
Results By industry, an elevated risk was observed in protective services work, which included firefighters and police officers (OR = 1.39, 95% CI=1.17–1.64) and the elevated risk was observed for those with ≥10 years duration of employment. An elevated risk was observed in legal work (OR = 3.51, 95% CI = 1.53–8.06) and a reduced risk was observed in tourism and recreation work (OR = 0.58, 95% CI = 0.40–0.83). By occupation, an elevated risk was observed in plumbing and gas workers (OR = 1.74, 95% CI = 1.06–2.84) and in farming and agriculture workers (OR = 1.35, 95% CI = 1.02–1.79). An elevated risk was also observed in other protective services occupations (excluding firefighters and police) (OR = 1.33, 95% CI = 1.09–1.62). An excess was also observed in firefighters (OR = 1.56, 95% CI = 0.90–2.69), based on small numbers.
Conclusions Despite the relatively large size of this study, few associations were observed. Excess risks among protective service workers, particularly firefighters, and agricultural workers have been previously observed. Additional studies using improved exposure assessment methods, including occupation specific chemical and physical exposures, are needed.