Postoperative Detection of Circulating Tumor Cells Predicts Tumor Recurrence in Colorectal Cancer Patients

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. 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. 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 %. 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.