Asthma and the risk of prostate cancer

Objective: The association between asthma and the risk of prostate cancer remains elusive. We aimed to evaluate the relationship between asthma and the onset of prostate cancer. Methods: We searched PubMed, Embase, and Cochrane databases for articles that assessed the association of asthma with the risk of prostate cancer through October 2015. We extracted odds ratio (OR) and calculated the corresponding 95% confidence interval (CI). We used random-effects models to calculate a pooled association between asthma and the risk of prostate cancer. Results: Fourteen studies were involved in the assessment of the association between asthma and prostate cancer risk. Asthma was not associated with the risk of prostate cancer in overall populations (OR 0.994, 95% CI 0.836-1.182), Caucasians (OR 0.922, 95% CI 0.825-1.030), and Asians (OR 5.022, 95% CI 0.415-60.793). The cumulative analysis also suggested a lack association between asthma and the risk of prostate cancer. Exclusion of any single study did not change the results significantly. No evidence of marked publication bias was observed. Conclusions: Our investigation indicated that asthma was not associated with prostate cancer risk in overall populations, Caucasians, and Asians.