Evaluation of diagnostic accuracy of DNA methylation biomarkers for bladder cancer: a systematic review and meta-analysis

Background: An increasing number of methylated genes have been reported as biomarkers for the diagnosis of bladder cancer. However, the results have been inconsistent. We performed a systematic review and meta-analysis to evaluate the feasibility and accuracy of using methylated genes as diagnostic markers for bladder cancer risk. Methods: Studies were systemically searched via the PubMed, ProQuest Health & Medical Complete and Springer Link database up to September 2013. Studies reporting the sensitivity and specificity of methylated biomarkers were extracted and the diagnostic accuracies were assessed by pooled diagnostic odds ratios (DORs) with 95% confidence intervals (CIs). Results: Methylated biomarkers showed accuracy for detecting bladder cancer (urine samples: DOR = 36.48, 95% CI = 7.12-186.81; tissue samples: DOR = 68.71, 95% CI = 36.52-129.29). Summary receiver operating characteristic analysis showed that markers in urine had better diagnostic power than those in tissues (area under the curve: 0.89 versus 0.75). Conclusion: The results of this study suggest that methylated biomarkers are suitable for diagnosing cancer risk.