Table 3.

Youden index of different CTC Cut-off values.

CTC cut-off (per 7.5 mL)	Sensitivity	Specificity	Youden index	Area Under Curve (AUC)
1	0.83	0.67	0.5	0.75
2	0.67	0.87	0.53	0.767
3	0.41	0.97	0.38	0.672

CTC, circulating tumor cell.