title: CD133 expression and the prognosis of colorectal cancer: a systematic review and meta-analysis.
abstract: OBJECTIVE
  CD133 has recently been reported as a marker of cancer stem-like cells in colorectal cancer (CRC). However, its predictive value in CRC still remains controversial. In this study, we aimed to evaluate the association between the expression of CD133 and clinicopathological features and the outcome of CRC patients by performing a meta-analysis.
  
  
  METHODS
  A comprehensive literature search for relevant studies published up to December 2012 was performed using PubMed, MEDLINE and ISI Web of Science. Only articles in which CD133 antigen was detected in situ localisation by immunohistochemical staining were included. This meta-analysis was done using RevMan 4.2 software.
  
  
  RESULTS
  We found that a total of 15 studies involving 810 CD133-high and 1487 CD133-low patients met the inclusion criteria for the analysis of 5-year overall survival (OS) rate. In a random-effects model, the results showed that CD133-high expression in colorectal cancer was an independent prognostic marker correlating with both OS rate (RR = 0.67, 95%CI 0.54-0.82, P<0.01) and disease free survival (DFS) rate (RR = 0.71, 95%CI 0.52-0.96, P = 0.03). CD133-high expression was also associated with more T3,4 tumor invasion, N positive and vascular invasion cases, corresponding to a risk difference of 1.12 (95%CI 1.01-1.23, P = 0.03), 1.31 (95%CI 1.06-1.63, P = 0.01) and 1.24 (95%CI 1.08-1.41, P<0.01), respectively. However, when types of histology, lymphatic invasion and distant metastasis were considered, CD133 overexpression was not significantly related with these clinicopathological parameters.
  
  
  CONCLUSIONS
  Our meta-analysis results suggest that CD133 is an efficient prognostic factor in CRC. Higher CD133 expression is significantly associated with poorer clinical outcome and some clinicopathological factors such as T category, N category and vascular invasion in CRC patients.
authors: Department of Gastrointestinal Tumor Surgery, Affiliated Tumor Hospital of Guangzhou Medical College, Guangzhou, China.
authors: Shicai
authors: S
authors: Chen
authors: Xinming
authors: X
authors: Song
authors: Zhihui
authors: Z
authors: Chen
authors: Xinxin
authors: X
authors: Li
authors: Mingzhe
authors: M
authors: Li
authors: Haiying
authors: H
authors: Liu
authors: Jianchang
authors: J
authors: Li
mesh_terms: D000071916:AC133 Antigen; D015703:Antigens, CD / Q000378:metabolism*; D015179:Colorectal Neoplasms / Q000235:genetics* / Q000473:pathology / Q000628:therapy; D018572:Disease-Free Survival; D015972:Gene Expression Regulation, Neoplastic; D006023:Glycoproteins / Q000378:metabolism*; D006801:Humans; D010455:Peptides / Q000378:metabolism*
chemical_list: D000071916:AC133 Antigen; D015703:Antigens, CD; D006023:Glycoproteins; C000606023:PROM1 protein, human; D010455:Peptides