Impact of circulating tumor cells in colorectal cancer patients undergoing laparoscopic surgery

Table 1 Comparisons of the two main approaches for detection of circulating tumor cells

Approaches	Cell viability	Sensitivity	Specificity	Disadvantages
Nucleic-acid-based approach (i.e., RT-PCR)	No	High	Low	Cytological analysis is not possible Cells cannot be visualized
Cytometric approach (i.e., immunocytochemistry, immunofluorescence and flow cytometry)	Yes	Low	High	EpCAM dependent

RT-PCR: Reverse transcriptase-polymerase chain reaction; EpCAM: Epithelial-cell adhesion molecule.

Table 2 Relationship between postoperative circulating free tumor cells and status of freedom from recurrence in patients of colorectal cancer undergoing laparoscopic surgery (n = 42)

	No recurrence	With recurrence	P value
Post-operative free CTC levels
≤ 100/106 NBCs	28 (82.4%)	2 (25.0%)	0.001
> 100/106 NBCs	6 (17.6%)	6 (75.0%)

CTC: Circulating tumor cell; NBC: Nucleated blood cell.