Clinical significance of perioperative EMT-CTC in rectal cancer patients receiving open/laparoscopic surgery.

The objective of this study was to explore the clinical significance of perioperative CTCs (circulating tumor cells) counts and EMT-CTCs (epithelial-mesenchymal transition-CTCs) in rectal cancer patients. A total of 30 patients with rectal cancer who underwent radical resection of rectal cancer at the Guangxi Zhuang Autonomous Region People's hospital were enrolled. Five ml peripheral blood was withdrawn from 30 patients with rectal cancer before the operation and seven days after the operation and at the corresponding time also from 20 healthy volunteers. CanPatrol™ CTC detection technique was used to enrich and identify CTCs and IER3 expression simultaneously. We found out that the preoperative total CTCs were correlated with lymph node metastasis (p=0.008) and tumor size, and mixed CTCs were closely correlated with lymph node metastasis (p=0.009). The number of IER3-positive total CTCs and mesenchymal CTCs were statistically associated with tumor size, p=0.034 and 0.043, respectively. The number of CTCs varied significantly before and after the operation in all patients (p=0.049). There were significant differences in CTCs variations between the open operation group and the laparoscopic operation group. In the laparoscopic operation group, the average number of single-cell CTCs was 6.9 before operation and 3.5 after the operation (p=0.013). In the open operation group, the average number of single-cell CTCs was 5.9 before operation and 4.2 after the operation. To conclude, surgery is associated with a decrease of CTCs in rectal cancer patients, especially in patients receiving laparoscopic surgery. The number of CTCs before the operation in rectal cancer patients is related to the size of tumors and regional lymph node metastasis. CTCs detection and characterization may be useful for clinical staging and lymph node dissection during operation.