Table 4. Sensitivity, PPV, NPV, and C-index for recurrence within the first 3 years in the patients followed up for at least 3 years.

Variables	Test cohort	Validation cohort
Sensitivity	64.3%	46.2%
Specificity	90.6%	87.2%
PPV	32.1%	23.1%
NPV	97.3%	95.1%
C-index	0.774	0.618

NPV, negative predictive value; PPV, positive predictive value.