Prostate cancer is the leading
cancer type diagnosed in American men and is the second leading
cancer diagnosed in men worldwide. Although studies have been conducted to investigate the association between
prostate cancer and exposure to pesticides and/or farming, the results have been inconsistent. We performed a meta-analysis to summarize the association of farming and
prostate cancer. The PubMed database was searched to identify all published case-control studies that evaluated farming as an occupational exposure by questionnaire or interview and
prostate cancer. Ten published and two unpublished studies were included in this analysis, yielding 3,978 cases and 7,393 controls.
Prostate cancer cases were almost four times more likely to be farmers compared with controls with benign prostate
hyperplasia (BPH; meta odds ratio [OR], crude = 3.83, 95% confidence interval [CI] = 1.96-7.48, Q-test p value = .352; two studies); similar results were obtained when non-BPH controls were considered, but with moderate heterogeneity between studies (meta OR crude = 1.38, 95% CI = 1.16-1.64, Q-test p value = .216, I (2) = 31% [95% CI = 0-73]; five studies). Reported
pesticide exposure was inversely associated with
prostate cancer (meta OR crude = 0.68, 95% CI = 0.49-0.96, Q-test p value = .331; four studies), whereas no association with exposure to
fertilizers was observed. Our findings confirm that farming is a risk factor for
prostate cancer, but this increased risk may not be due to exposure to pesticides.