Long-term prognostic value of cytokeratin 20 mRNA-positive cells in blood and bone marrow of patients with localized colorectal cancer.

INTRODUCTION This study aimed to evaluate whether the presence of circulating and disseminated tumor cells (CTCs/DTCs) in peripheral blood (PB), tumor-draining blood (TDB), and bone marrow (BM) serves as a negative prognostic indicator for long-term cancer-specific survival (CSS) in patients with localized colorectal cancer (CRC). Additionally, associations between CTC/DTC detection and clinical as well as pathological characteristics of the disease were investigated.

MATERIALS AND METHODS A cohort of 188 patients with localized CRC underwent analysis for the presence of CTCs/DTCs in PB, TDB, and BM. Samples were collected preoperatively, immediately postoperatively, and one month following surgery. Detection was performed via quantitative polymerase chain reaction (qPCR) targeting cytokeratin 20 (CK20) mRNA, an epithelial biomarker, in circulating blood cells and bone marrow specimens.

RESULTS During a median follow-up of 116.5 months, 81 out of 149 patients (54.7%) with stage I-III CRC succumbed to the disease. Detection of CTCs/DTCs was significantly associated with higher tumor stage and KRAS mutation status. The presence of CK20 mRNA-positive CTCs in PB one month after surgery was associated with significantly reduced disease-free survival (DFS), overall survival (OS), and cancer-specific survival (CSS) (log-rank p = 0.026, 0.003, and 0.012, respectively). Similarly, patients exhibiting CK20 mRNA-positive DTCs in BM one month postoperatively demonstrated significantly shorter DFS and CSS (log-rank p = 0.027 and 0.017, respectively).

CONCLUSION Detection of CK20 mRNA-positive CTCs/DTCs in PB and/or BM one month after surgical resection constitutes an independent negative prognostic factor for both long-term DFS and CSS in patients with non-metastatic CRC.