Background: Tumor initiating cells are a small subset of cancer cells responsible for tumor growth and recurrence. The status of tumor initiating cells was measured using the surface markers CD133 (prominin-1) and ESA (epithelial-specific antigen). The aims of this study were to investigate the significance of CD133+/ESA+ cells in mesenteric venous blood (MVB) and tumor mass (TM) for overall survival (OS) and disease-free survival (DFS) in colorectal cancer (CRC) patients undergoing curative resection. Materials and methods: A total of 229 CRC patients undergoing curative resection were prospectively enrolled in the study. Using CD133 and ESA as surface markers, CD133+/ESA+ cells were enumerated from MVB and TM using flow cytometry. Results: We analyzed the presence of CD133+/ESA+ cells in TM from 158 patients and found no correlation to patient DFS, OS, or clinical stage. In 135 patients, an analysis of CD133+/ESA+ cells in MVB showed an inverse correlation with both DFS and OS (P=0.014 and P=0.008, respectively). It exhibited an increase-then-decrease pattern with the peak in stage II patients. A multivariate Cox analysis demonstrated that the status of CD133+/ESA+ cells in MVB, but not the TM, was a significant prognostic factor for DFS and OS (P=0.003 and P=0.011, respectively). Conclusions: The status of CD133+/ESA+ cells in MVB, but not in TM, could be a useful indicator for predicting tumor recurrence and a prognostic marker for CRC patients.
- Epithelial-specific antigen