Abstract: Abstract： Objective To assess the role of E-cadherin (CDH1) promoter methylation in bladder carcinogenesis by meta-analysis. Methods The relevant database were searched by the retrieval strategy of Cochrane network. All included studies were collected following data: the first author’ s surname, publication year of article, country, language of publication, design of study, sample size, ethnicity, histological subtypes, methylation detection method and genotype frequencies etc. This meta-analysis was performed using the STATA 12.0 software. The crude odds ratio (OR) with 95% confidence interval (CI) was calculated. Results Ten case-control studies were included in this meta-analysis. The methylation frequency of CDH1 was detected in 620 bladder cancer tissues and 341 normal or cancerous tissues. Results showed that the methylation frequency of CDH1 was significantly higher in bladder cancer tissue than that of normal or cancerous tissue (OR = 3.09, 95% CI: 1.13~8.50, P = 0.029). Furthermore, the ethnicity-stratified analysis revealed that the methylation frequency of CDH1 was significantly higher in bladder cancer tissue of Asian populations than that of normal or cancerous tissue (OR=3.85, 95% CI: 1.46~10.14, P=0.006), but no such association was found in Caucasian populations（OR=2.22, 95%CI: 0.38-12.91, P= 0.375). The subgroup analysis based on the detection methods revealed that there was a statistically significant difference in the methylation frequency of CDH1 between bladder cancer tissue and adjacent tissues and normal tissues under the MSP subgroup (P < 0.001), while such association was not observed under the Q-MSP subgroup (P = 0.818). Conclusion Pro⁃ moter methylation of CDH1 gene may be involved in the occurrence and development of bladder cancer, which may serve as a biomarker for diagnosis and prognosis of bladder cancer.

Key words: E-cadherin, methylation, bladder cancer, Meta-analysis