title: Aberrant promoter methylation of RASSF1A gene may be correlated with colorectal carcinogenesis: a meta-analysis.
abstract: We conducted a meta-analysis of cohort studies to evaluate the potential role of RASSF1A promoter methylation in colorectal carcinogenesis. A range of electronic databases were searched: PubMed (1966-2013), the Cochrane Library Database (Issue 12, 2013), EMBASE (1980-2013), CINAHL (1982-2013), Web of Science (1945-2013) and the Chinese Biomedical Database (CBM) (1982-2013) without language restrictions. Meta-analysis was conducted using the STATA 12.0 software. Crude odds ratio (OR) with 95% confidence interval (95% CI) was calculated. Eleven clinical cohort studies with a total of 1,505 colorectal cancer (CRC) patients that met all inclusion criteria were included in our meta-analysis. The results of our meta-analysis revealed that the frequency of RASSF1A promoter methylation was strongly correlated with clinical stage (OR = 1.69, 95% CI 1.16-2.44, P = 0.006), histological grade (OR = 1.92, 95% CI 1.22-3.04, P = 0.005) and distant metastasis (OR = 2.59, 95% CI 1.46-4.60, P = 0.037) of CRC patients. However, we observed no positive correlations of RASSF1A promoter methylation with gender (OR = 1.04, 95% CI 0.74-1.46, P = 0.842), age (OR = 1.70, 95% CI 0.98-2.93, P = 0.057) and lymph node metastasis (OR = 1.65, 95% CI 0.87-3.14, P = 0.127) of CRC patients. Further subgroup analysis by ethnicity demonstrated that RASSF1A promoter methylation was correlated with clinicopathological characteristics of CRC patients among Asians (clinical stage: OR = 2.55, 95% CI 1.55-4.20, P < 0.001; histological grade: OR = 2.70, 95% CI 1.44-5.06, P = 0.002; lymph node metastasis: OR = 4.09, 95% CI 1.49-11.26, P = 0.006; distant metastasis: OR = 5.38, 95% CI 1.73-16.70, P = 0.004), but not among Caucasians and Africans (all P > 0.05). Our meta-analysis has shown positive correlations between aberrant promoter methylation of RASSF1A gene and clinicopathological characteristics of CRC patients, especially among Asians.
authors.affiliation: Department of General Surgery, Shengjing Hospital of China Medical University, Huaxiang Road No. 39, Tiexi, Shenyang, 110022, People's Republic of China, wangheling1127@126.com.
authors.forename: He-Ling
authors.initials: HL
authors.lastname: Wang
authors.forename: Yu
authors.initials: Y
authors.lastname: Zhang
authors.forename: Peng
authors.initials: P
authors.lastname: Liu
authors.forename: Ping-Yi
authors.initials: PY
authors.lastname: Zhou
mesh_terms: D044466:Asian People / Q000235:genetics; D063646:Carcinogenesis / Q000235:genetics*; D015179:Colorectal Neoplasms / Q000235:genetics* / Q000473:pathology; D019175:DNA Methylation / Q000235:genetics*; D020022:Genetic Predisposition to Disease; D006801:Humans; D008875:Middle Aged; D011401:Promoter Regions, Genetic; D025521:Tumor Suppressor Proteins / Q000235:genetics*
chemical_list: C411762:RASSF1 protein, human; D025521:Tumor Suppressor Proteins