Prognostic significance of systemic immune-inflammation index in patients with intrahepatic cholangiocarcinoma undergoing hepatic resection

Table 1 Baseline characteristics of included patients

Variables	All patients (n = 530)	Derivation cohort (n = 265)	Validation cohort (n = 265)	P value
Patient factors/laboratory parameters
Age, yr	57.2 (10.7)	57.9 (10.5)	56.5 (10.8)	0.131
Male gender, n (%)	256 (48.3)	134 (50.6)	122 (46.0)	0.339
HBsAg (positive), n (%)	153 (29.0)	80 (30.3)	73 (27.7)	0.565
Hepatolithiasis, n (%)	89 (16.8)	42 (15.6)	47 (17.9)	0.487
CA-199 < 22, n (%)	150 (29.0)	77 (30.0)	73 (28.0)	0.738
Platelet	178 (72)	179 (73)	177 (71)	0.778
Neutrophil	4.6 (2.1)	4.6 (2.3)	4.6 (2.0)	0.976
Lymphocyte	1.6 (0.9)	1.6 (1.2)	1.6 (0.5)	0.641
NLR	3.38 (2.95)	3.34 (2.22)	3.42 (3.54)	0.746
PLR	126 (68)	127 (65)	125 (70)	0.716
SII	612 (635)	605 (495)	619 (751)	0.803
Histological and gross features of tumors
Tumor size, cm	6.0 (2.7)	6.0 (2.7)	6.0 (2.7)	0.783
Solitary tumor, n (%)	373 (70.4)	196 (74.0)	177 (66.8)	0.087
Well tumor differentiation, n (%)	22 (4.2)	11 (4.2)	11 (4.2)	1.000
Macrovascular invasion, n (%)	123 (23.2)	71 (26.8)	52 (19.6)	0.064
Microvascular invasion, n (%)	54 (10.2)	27 (10.2)	27 (10.2)	1.000
Node positive, n (%)	129 (24.3)	61 (23.0)	68 (25.7)	0.544
Perineural invasion, n (%)	80 (15.1)	38 (14.3)	42 (15.8)	0.716
TNM stage, n (%)				0.902
IA	63 (11.9)	33 (12.5)	30 (11.3)
IB	38 (7.2)	21 (7.9)	17 (6.4)
II	56 (10.6)	26 (9.8)	30 (11.3)
IIIA	242 (45.7)	122 (46.0)	120 (45.3)
IIIB	131 (24.7)	63 (23.8)	68 (25.7)
Follow-up, median (range)	18.0 (1.0-115.4)	18.2 (1.0-115.4)	17.8 (1.2-104.5)

Age, platelet, neutrophil and lymphocyte were shown as mean (SD). M: Male; F: Female; CA-199: Carbohydrate antigen-199; TNM: Tumor-node-metastasis; NLR: Neutrophil to lymphocyte ratio; PLR: Platelet to lymphocyte ratio; SII: Systemic immune-inflammation index; HR: Hazard ratio; CI: Confidence interval.