Clinical Significance Of CD133 Expression In Gastric Cancer:A Systematic Review

Objective Our study aimed to systematically review the expression and clinical significance of CD133 in gastric cancer and to clarify the role that CD133 plays in the carcinogenesis of gastric cancer.Methods Searches in the databases such as PubMed, EMbase, Web of Knowledge, The Cochrane Library (Issue 10,2013), CBM, VIP, CNKI and WanFang Data were performed to collect case-control studies about the association between the CD133 expression and gastric cancer up to October 2013. Two reviewers independently screened the literature according to the inclusion and exclusion criteria, extracted the data, and assessed the methodological quality of the included studies. RevMan 5.2 software was used for meta-analysis, STATA 11.0 was used to conduct Begg’s and Egger’s tests, and GRADEpro 3.6 was used to rate the quality of evidence.Results Nine case-control studies involving 623 patients were included. The results of the meta-analyses showed that, there were significant differences of CD 133 expression in the following comparisons:gastric cancer tissues vs. normal esophageal tissues (OR=3.89,95% CI 1.87 to 8.11, P=0.0003), lymph node metastasis vs. non-lymph node metastasis (OR=2.75,95% CI 1.99 to 3.81, P<0.000 01), clinical stages Ⅲ-Ⅳ vs. clinical stages Ⅰ-Ⅱ (OR=2.83,95% CI 2.13 to 3.76, P<0.000 01), as well as distant metastasis vs. non-distant metastasis (OR=2.38,95% CI 1.47 to 3.85, P=0.000 4). While no significant difference was found between the cell differentiation G1-G2 vs. cell differentiation G3 (OR=1.70,95% CI 0.90 to 3.21, P=0.10). Begg’s and Egger’s tests showed that there was no publication bias in this systematic review. Three outcomes were rated as moderate quality of evidence, and the other two were rated as low.Conclusions Over-expression of CD 133 is associated with lymph node metastasis, distant metastasis and poor TNM stage, which suggests that CD 133 may participate in the carcinogenesis of gastric cancer. However, more large-sample high-quality case-control studies are still needed to verify these results.