Meta-analyses of methylation markers for prostate cancer.

Prostate cancer (PCa) is the most frequently diagnosed non-cutaneous cancer that has become the sixth leading cause of mortality in both the developed and developing countries. Accumulating evidence showed a number of genes with aberrant DNA methylation in the pathogenesis of PCa. Here, we conducted a systematic meta-analysis to evaluate the contribution of aberrantly methylated genes to the risk of PCa. Relevant methylation studies were retrieved from PubMed and Wanfang literature databases. In the meta-analysis, Mantel-Haenszel odds ratios (ORs) and 95 % confidence intervals (CIs) were calculated for each methylation event under appropriate models. A total of 594 publications were initially retrieved from PubMed and Wanfang literature database. After a three-step filtration, we harvested 39 case-control articles investigating the role of gene methylation in the prediction of PCa risk. Among the 31 genes involved, 24 genes were shown to be significantly hypermethylated in the PCa patients. Our meta-analyses identified strong associations of four aberrantly methylated genes (GSTP1, RASSF1, p16, and RARB) with PCa. Further research is needed to strengthen our findings in the future.