Clinicopathological significance of CD133 in lung cancer: A meta-analysis.

CD133 is one of the most commonly used markers of lung cancer stem cells (CSCs), which are characterized by their ability for self-renewal and tumorigenicity. However, the clinical value and significance of CD133 in lung cancer remains controversial. Due to the limited size of the individual studies, the association between CD133 and the clinicopathological characteristics of lung cancer had not been fully elucidated. A meta-analysis based on published studies was performed with the aim of evaluating the effect of CD133 on the clinicopathological characteristics of lung cancer and to investigate the role of CSCs in the prognosis of lung cancer. A total of 15 eligible studies were included in this meta-analysis and our results indicated that a positive CD133 expression was significantly associated with poor differentiation and lymph node metastasis, although it was not associated with tumor stage or histological type. Therefore, CD133 may be considered as a prognostic maker of lung cancer. Further clinical studies, with larger patient samples, unified methods and cut-off levels to detect CD133 expression, classified by tumor stage, therapeutic schedule, follow-up time and survival events, are required to determine the role of CD133 in clinical application and the association between CD133 and the prognosis of lung cancer.