Table 1.

Univariate and multivariate Cox proportional analysis for overall survival (cohort #1, N = 137)

	n	Univariate analysis			Multivariate analysis
		HR	95% CI	p value	HR	95% CI	p value
Gender
Male	88	1
Female	49	0.884	0.585–1.336	0.558
Age (years)
≥ 65	57	1
< 65	80	0.855	0.573–1.276	0.444
Location
Head	88	1			1
Other	49	0.599	0.394-0.911	0.016	0.507	0.327–.786	0.002
Grading
G1	6	1			1
G2	102	1.728	0.628–4.755	0.29	2.661	0.887–7.981	0.081
G3	28	3.911	1.352–11.311	0.012	6.182	1.998–19.128	0.002
G4a	1	–	–	–	–	–	–
pStage
I	21	1			1
II	63	2.885	1.354–6.144	0.006	2.858	1.331–6.137	0.007
III	45	4.221	1.977–9.014	< 0.001	4.062	1.881–8.771	< 0.001
IV	8	5.57	2.075–14.95	0.001	6.93	2.357–20.38	< 0.001
Vascular invasion
Yes	37	1
No	100	1.027	0.66–1.596	0.907
CA199 (U/ml)
< 37	33	1
≥ 37	104	1.486	0.928–2.378	0.099
Diameter (cm)
≥ 4	69	1
< 4	68	1.477	1–0.182	0.0503
Procedure
PD	85	1
DP	43	0.688	0.446–1.061	0.09
TP	9	0.747	0.323–1.728	0.495
Postoperative chemotherapy
No	57	1			1
Yes	80	0.488	0.324–0.734	0.001	0.474	0.312–0.722	0.001
VISTA in TCs
Low	101	1			1
High	36	0.588	0.365–0.946	0.029	0.452	0.269–0.757	0.003
VISTA in ICs
Low	82	1
High	55	1.116	0.745–1.671	0.595
VISTA in ECs
Low	105	1
High	32	0.97	0.603–1.561	0.902
PD-L1
Low	107	1			1
High	30	1.759	1.085–2.853	0.022	2.242	1.344–3.738	0.002

HR hazard ratio, CI confidence interval, TC tumor cells, IC immune cells, ECs endothelial cells, PD pancreaticoduodenectomy, DP distal pancreatectomy, TP total pancreatectomy

^aBecause small number of cases in these groups, the survival analysis was meaningless