Aberrant promoter methylation of the SFRP1 gene may contribute to colorectal carcinogenesis: a meta-analysis

This meta-analysis of published cohort studies was conducted to evaluate whether promoter methylation of the secreted frizzled-related protein 1 (SFRP1) gene contributes to colorectal carcinogenesis. The Web of Science (1945 similar to 2013), the Cochrane Library Database (Issue 12, 2013), PubMed (1966 similar to 2013), EMBASE (1980 similar to 2013), CINAHL (1982 similar to 2013), and the Chinese Biomedical Database (CBM) (1982 similar to 2013) were searched without language restrictions. Meta-analysis was conducted using the STATA 12.0 software. We calculated odds ratio (OR) and its 95 % confidence interval (95 % CI) to estimate the correlations between SFRP1 promoter methylation and colorectal carcinogenesis. In the present meta-analysis, 8 cohort studies with a total of 942 patients with colorectal cancer (CRC) were included. The pooled results revealed that the frequency of SFRP1 promoter methylation in cancer tissues were significantly higher than those of normal, adjacent, and benign tissues (cancer tissues vs. normal tissues: OR = 31.49, 95 % CI = 17.57 similar to 56.44, P < 0.001; cancer tissues vs. adjacent tissues: OR = 5.95, 95 % CI 3.12 - 10.00, P < 0.001; cancer tissues vs. benign tissues: OR = 3.01, 95 % CI 1.72 similar to 5.27, P < 0.001; respectively). Furthermore, ethnicity-stratified analysis indicated that SFRP1 promoter methylation was strongly correlated with colorectal carcinogenesis among both Asians and Caucasians (all P < 0.05). Our findings provide empirical evidence that SFRP1 promoter methylation may be correlated with the pathogenesis of CRC.