Risk factors for occult metastasis detected by inflammation-based prognostic scores and tumor markers in biliary tract cancer

Table 3 Cut-off values of each variables determined using receiver operator characteristic curves for all BTC patients

Variables	Cut-off value	Sensitivity	Specificity	PPV	AUC
CA19-9	255 IU/mL	0.423	0.823	0.229	0.688
CEA	7 ng/mL	0.346	0.919	0.346	0.645
NLR	3	0.615	0.71	0.208	0.667

PPV: Positive predictive value; AUC: Area under the curve; BTC: Biliary tract cancer.