Pesticide exposure and risk of bladder cancer: A meta-analysis

Objective We conducted a meta-analysis to quantitatively evaluate the correlation between pesticide exposure and the risk of bladder cancer by summarizing the results of published case-control and cohort studies. Methods A systematic literature search of articles update to February 2015 was conducted via Pubmed, Web of Science, Cochrane Library, and the Chinese National Knowledge Infrastructure (CNKI) databases, and the references of the retrieved articles. Fixed-or random-effect models were used to summarize the estimates of OR with 95% CIs for the highest versus the lowest exposure of pesticide. Results The pooled OR estimates indicated that pesticide exposure was associated with an increased risk of bladder cancer (OR= 1.649, 95% CI 1.223-2.223). In subgroup analysis, we detected pesticide exposure demonstrated as a significant risk factor on bladder cancer in America (OR= 1.741, 95% CI 1.270-2.388). Similar results were discovered in both case-control group and cohort group (OR= 2.075, 95% CI 1.183-3.638, OR= 1.146, 95% CI 1.074-1.223, respectively). No evidence of publication bias was found by Begg's or Egger's test (P = 0.210, P = 0.358, respectively). Conclusion In conclusion, our meta-analysis indicated that pesticide exposure was associated with an increased risk of bladder cancer. Further researches should be conducted to confirm the findings in our study and better clarify the potential biological mechanisms.