LGR5, a relevant marker of cancer stem cells, indicates a poor prognosis in colorectal cancer patients: A meta-analysis

Background: Leucine-rich repeat-containing G protein-coupled receptor 5 (Lgr5) has been identified as a putative intestinal stem cell marker. However, the clinical prognosis of Lgr5 is still controversial in colorectal cancer (CRC). To systematically summarize the clinical prognostic function of Lgr5 in colorectal cancer, we performed this meta-analysis. Methods: Published articles which assessed the clinical or prognostic role of Lgr5 was searched in Pubmed, Embase and Springer and collected until the publication month of February 2014. The association of Lgr5 expression with clinical outcomes was investigated by a meta-analysis. Results: A total of 8 studies have been up to the inclusion standard, comprised 2139 patients. Lgr5 showed no relationship with the gender of patients (OR = 0.919, 95% CI = 0.730-1.157, P = 0.473) and the depth of invasion (OR = 2.616, CI 95% = 0.947-7.221, P = 0.063). Lgr5 was significantly associated with lymph node metastasis (OR = 2.248, 95% CI = 1.205-4.192, P = 0.011), tumor distance metastasis (OR = 3.872, 95% CI = 2.792-5.370, P < 0.001) and classification of TNM (pooled OR = 3.264, 95% CI = 1.731-6.155, P < 0.001). Overall, overexpression of Lgr5 was statistically related to the reduced overall survival (HR = 6.130, 95% CI = 2.845-13.210, P < 0.001). Conclusions: Lgr5 participates in the progression of CRC as a putative factor. Overexpression of Lgr5 was distinctly correlated with poor patient survival. These findings suggested that Lgr5 might serve as an efficient biomarker for prognostic indicator, and could be a new molecular target in colorectal cancer therapy. (C) 2014 Elsevier Masson SAS. All rights reserved.