Minimal residual disease and prognostic significance of circulating tumour cells in early-stage colorectal cancer.

Aim: The recurrence rate of colorectal cancer remains high even after radical surgery. Existing criteria for administering adjuvant treatment lack sufficient precision, often leading to undertreatment or overtreatment. This study investigates circulating tumour cells (CTCs) as a potential prognostic biomarker to improve the accuracy of patient selection.

Methods: Forty-six colorectal cancer patients without distant metastases who underwent radical surgery were enrolled in this prospective study conducted at Tomas Bata Hospital in Zlín. The study protocol was approved by the hospital's Ethics Committee. Circulating tumour cells (CTCs) were measured in peripheral blood samples collected preoperatively, on the second postoperative day, and one month after surgery. CTCs were detected and characterized using semiautomated microscopy. Comprehensive clinicopathological data were recorded as part of standardized perioperative care. The prognostic significance of CTCs was evaluated based on the time to recurrence (TTR) parameter.

Results And Conclusion: Growing evidence from circulating tumour cell (CTC) research supports their potential role as a valuable biomarker in cancer management. In this study involving stage I-III colorectal cancer patients, a recurrence rate of 20% was observed among individuals with detectable CTCs, whereas no recurrence occurred in patients with a sustained absence of CTCs. Despite this apparent difference, the time to recurrence (TTR) did not differ significantly between the groups (log-rank test, P=0.175). Although the result was not statistically significant, the observed trend suggests a possible prognostic value of CTCs that merits investigation in a larger cohort. Furthermore, neither individual time-point measurements nor dynamic changes in CTC levels demonstrated a significant correlation with TTR.