Abstract
Objective
The present study was performed to examine the CD133 expression in colorectal cancer and to analyze its relationship with microsatellite instability (MSI) and the clinicopathological factors, including patient survival.
Methods
The CD133 mRNA levels in 61 primary colorectal adenocarcinomas were analyzed by reverse transcriptaseโpolymerase chain reaction, with normalization relative to GAPDH. Five microsatellite markers were analyzed to evaluate MSI.
Results
A CD133 mRNA expression was significantly associated with the depth of invasion (Pโ=โ0.017), lymph node involvement (Pโ=โ0.012), and lymphovascular invasion (Pโ=โ0.019). A CD133 expression was significantly correlated with the MSI status (Pโ=โ0.035). With a median followโup period of 45 months, the 5โyear diseaseโfree survival rate of patients with a low CD133 mRNA expression was significantly higher than that of those patients with high levels of CD133 mRNA expression (82.9% and 59.0%, respectively; Pโ=โ0.027). However, on the multivariate analysis, a CD133 mRNA expression was not an independent predictor of diseaseโfree survival.
Conclusions
Elevated CD133 mRNA levels may represent more aggressive tumor biology and poorer survival in patients with colorectal cancer, correlating with a high level of MSI status. Larger prospective studies are required to confirm these findings. J. Surg. Oncol. 2010;102:765โ770. ยฉ 2010 WileyโLiss, Inc.