Clinicopathological and Prognostic Significance of CD133 in Glioma Patients: A Meta-Analysis

In recent years, CD133 has been identified as a cancer stem cell (CSC) marker in gliomas. Nevertheless, the clinical and prognostic value of CD133 in glioma patients remains controversial. Therefore, we conducted a systematic meta-analysis to evaluate the correlation of CD133 with World Health Organization (WHO) grade, age, gender, overall survival (OS), and progression-free survival (PFS) in glioma patients. Eligible studies on this subject were included, and then pooled odd ratios (ORs) and hazard ratios (HRs) with 95 % confidence intervals (95 % CIs) were estimated. Publication bias was assessed by the funnel plots, and heterogeneity and sensitivity were analyzed as well. In the present study, 21 articles with the total number of 1535 patients were included. High expression of CD133 in glioma patients was associated with high WHO grade (III + IV) (n(-)11, OR 5.10, 95 % CI 2.99-8.69; p = 0.000), rather than age (n(-)4, OR 2.54, 95 % CI 0.68-9.52; p(-)0.167) and gender (n(-)4, OR 0.71, 95 % CI 0.21-2.45; p (-)0.587). In addition, survival analysis demonstrated a significant association between CD133 high expression and poor 2-year OS (n (-)11, HR 2.18, 95 % CI 1.29-3.7; p (-)0.004), 5-year OS (n (-)4, HR 10.39, 95 % CI 2.59-41.63; p (-)0.001), as well as PFS (n (-)10, HR 2.34, 95 % CI 1.62-3.37; p (-)0.000). Taken together, this study suggests that CD133 expression correlates to higher grade of gliomas and worse prognosis in glioma patients. Thus, CD133 could be recommended as a useful pathological and prognostic biomarker in clinical practice.