Document Type: Systematic Review and Meta-analysis
Department of Biostatistics, Psychosocial Injuries Research Center, Ilam University of Medical Sciences, Ilam, Iran.
Student Research Committee, Ilam University of Medical Sciences, Ilam, Iran.
Modeling of Noncommunicable Diseases Research Center, Department of Epidemiology, School of Public Health, Hamadan University of Medical Sciences, Hamadan, Iran.
Dezful University of Medical Sciences, Dezful, Iran.
Background: Evidence of relationship between selenium and prostate cancer has been inconsistent. The present metaanalysis was conducted to determine relationship between selenium and prostate cancer. Methods: A systematic review and meta-analysis was carried out using preferred reporting items for systematic reviews and meta-analysis (PRISMA). We searched PubMed, Scopus, Web of Science, ScienceDirect, Embase, CINAHL, Cochrane Library, EBSCO and
Google scholar search engines and the reference lists of the retrieved papers for relevant data, without any limitation
regarding language or time until 2016. Heterogeneity among studies was evaluated using Q test and I2 Index. Finally,
a random effects model was used for combining results using STATA software version 11.1. Psignificant. Results: Thirty-eight studies including 36,419 cases and 105,293 controls were included in the final analysis. The pooled relative risk (RR) of relation between selenium and prostate cancer was 0.86 (95% Confidence Interval [CI]:0.78-0.94). Sub-group analyses based on case-control, cohort, and RCT studies gave values of 0.89 (95% CI:0.80-1.00), 0.77 (95% CI: 0.52-1.14) and 0.90 (95% CI: 0.74-1.09), respectively. RRs based on serum, plasma and nail samples were 0.69 (95% CI: 0.51-0.95), 0.85 (95% CI: 0.61-1.17), 0.66 (95% CI: 0.41-1.05), respectively. According to 10 studies, investigated the relation between advanced prostate cancer and selenium in which the RR was 0.67 (95% CI: 0.52-0.87). Conclusions: This meta-analysis indicated that selenium most probably has a protective role against development of prostate cancer and its progression to advanced stages. Therefore, selenium supplementation can be proposed for prevention of prostate cancer.