Clinical significance of circulating tumor cells, including cancer stem-like cells, in peripheral blood for recurrence and prognosis in patients with dukes' stage B and C colorectal cancer

Abstract

Purpose Using multiple genetic markers, including cancer stem-like cells, we evaluated the clinical significance of circulating tumor cells (CTCs) as a prognostic factor for overall survival (OS) and disease-free survival (DFS) in the peripheral blood (PB) of patients with colorectal cancer (CRC) who had undergone curative surgery. Patients and Methods In a multi-institutional study, 735 patients with CRC were assigned to a retrospective training set (n=420) or prospective validation set (n=315). CTCs that expressed carcinoembryonic antigen (CEA), cytokeratin (CK) 19, CK20, and/or CD133 (CEA/CK/CD133) mRNA in PB were detected using real-time reverse transcription polymerase chain reaction assay. Results In the training sets, OS and DFS of patients who were positive for CEA/CK/CD133 were significantly worse than those of patients who were negative for these markers (P < .003 and P < .001 in Dukes' stage B; P < .001) and DFS (HR, 3.02; 95% CI, 1.83 to 5.00; P