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

Table 1 Patients' demographics

	Type of operations
Characteristics	EL (n = 26)	R (n = 210)	P value
Age, yr1	69 (55-83)	70 (25-89)	0.57
Sex (male / female)	12/14	122/88	0.29
BMI (kg/m2)1	21.8 (18-31.6)	21.8 (15.6-40.1)	0.98
Location of the tumor, n
Intrahepatic bile duct (n = 39)	6	33
Perihilar bile duct (n = 55)	3	52
Distal bile duct (n = 55)	8	47
Gallbladder (n = 50)	9	41
Papilla of Vater (n = 37)	0	37

¹Data are presented as median (range). EL: Exploratory laparotomy; R: Resected.