title: The prognostic value of CDKN2A hypermethylation in colorectal cancer: a meta-analysis.
abstract: BACKGROUND
  The prognostic value of CDKN2A promoter hypermethylation in colorectal cancer remains controversial. We systematically reviewed the evidence for assessment of CDKN2A methylation in colorectal cancer to elucidate this issue.
  
  
  METHODS
  Pubmed, Embase and ISI web of knowledge were searched to identify eligible studies to evaluate the association of CDKN2A hypermethylation and overall survival and clinicopathological features of colorectal cancer patients. Combined hazard ratios (HRs) or odds ratios (ORs) with 95% confidence interval (95% CI) were pooled using a random-effects model.
  
  
  RESULTS
  A total of 11 studies encompassing 3440 patients were included in the meta-analysis. CDKN2A hypermethylation had an unfavourable impact on OS of patients with colorectal cancer (HR 1.65, 95% CI 1.29-2.11). Subgroup analysis indicated that CDKN2A hypermethylation was significantly correlated with OS in Europe (HR 1.49; 95% CI 1.28-1.74) and Asia (HR 3.30; 95% CI 1.68-6.46). Furthermore, there was a significant association between CDKN2A hypermethylation and lymphovascular invasion (OR 1.68, 95% CI 1.15-2.47), lymph node metastasis (OR 1.68, 95% CI 1.09-2.59) and proximal tumour location (OR 2.09, 95% CI 1.34-3.26) of colorectal cancer.
  
  
  CONCLUSIONS
  This meta-analysis indicated that CDKN2A hypermethylation might be a predictive factor for unfavourable prognosis of colorectal cancer patients.
authors.affiliation: Department of Gastroenterology, The First Affiliated Hospital of Sun Yat-sen University, 58 Zhongshan II Road, Guangzhou 510080, China.
authors.forename: X
authors.initials: X
authors.lastname: Xing
authors.forename: W
authors.initials: W
authors.lastname: Cai
authors.forename: H
authors.initials: H
authors.lastname: Shi
authors.forename: Y
authors.initials: Y
authors.lastname: Wang
authors.forename: M
authors.initials: M
authors.lastname: Li
authors.forename: J
authors.initials: J
authors.lastname: Jiao
authors.forename: M
authors.initials: M
authors.lastname: Chen
mesh_terms: D002277:Carcinoma / Q000175:diagnosis* / Q000235:genetics / Q000401:mortality; D015179:Colorectal Neoplasms / Q000175:diagnosis* / Q000235:genetics / Q000401:mortality; D019175:DNA Methylation / Q000502:physiology*; D015972:Gene Expression Regulation, Neoplastic; D019942:Genes, p16 / Q000502:physiology; D006801:Humans; D011237:Predictive Value of Tests; D011379:Prognosis; D016019:Survival Analysis