Preoperative systemic inflammatory response index as a prognostic marker for distal cholangiocarcinoma after pancreatoduodenectomy

Table 2 Pathological characteristics of the patients classified by the systemic inflammatory response index

Variables	Total (n = 216)	Low SIRI (n = 123)	High SIRI (n = 93)	P value
pT stage
Tis	3	2	1	0.654
T1, T2	26	17	9
T3, T4	184	103	81
Unknown	3	1	2
pN stage
N0	111	67	44	0.676
N1	74	41	33
N2	29	14	15
Unknown	2	1	1
pM stage
M0	204	118	86	0.271
M1	12	5	7
Tumor differentiation
Well	25	19	6	0.097
Moderate	90	54	36
Poor	26	13	13
Other	75	37	38
Tumor size (cm)
≥ 1.8	140	74	66	0.045a
< 1.8	74	49	25
Unknown	2	0	2
Microscopic lymphatic invasion
Yes	103	55	48	0.578
No	111	67	44
Unknown	2	1	1
Microscopic venous invasion
Yes	36	17	19	0.214
No	179	106	73
Unknown	1	0	1
Microscopic arterial invasion
Yes	6	2	4	0.344
No	207	120	87
Unknown	3	1	2
Peripheral organ invasion
Yes	3	2	1	0.670
No	210	120	90
Unknown	3	1	2
Venous invasion type
1-2	24	15	9
3-4	12	2	10	0.014a
No	180	106	74
Perineural invasion
Yes	189	104	85	0.268
No	25	18	7
Unknown	2	1	1
Distant metastasis
Yes	12	5	7	0.189
No	204	118	76
Incisal edge
Positive	24	14	10	0.884
Negative	192	109	83
Residual tumor status
R0	191	109	82	0.490
R1	19	10	9
R2	6	2	4

^aP < 0.05.

SIRI: Systemic inflammatory response index.