Introduction: Circulating tumor cells are thought to play a crucial role in the development of distant metastases. Their detection in the blood of colorectal cancer patients may be linked to poor outcome, but current evidence is controversial.
Materials and methods: Pre- and postoperative flow cytometric analysis of blood samples was carried out in 76 colorectal cancer patients undergoing surgical resection. The EpCAM/CD326 epithelial surface antigen was used to identify circulating tumor cells.
Results: Fifty-four (71%) patients showed circulating tumor cells preoperatively, and all metastatic patients showed high levels of circulating tumor cells. Surgical resection resulted in a significant decrease in the levels of circulating tumor cells. Among 69 patients undergoing radical surgery, 16 had high postoperative levels of circulating tumor cells, and 12 (75%) experienced tumor recurrence. High postoperative level of circulating tumor cells was the only independent variable related to cancer relapse. In patients without circulating tumor cells, the progression-free survival rate increased from 16 to 86%, with a reduction in the risk of tumor relapse greater than 90%.
Conclusions: High postoperative levels of circulating tumor cells accurately predicted tumor recurrence, suggesting that assessment of circulating tumor cells could optimize tailored management of colorectal cancer patients.