Table 2.

Univariate and multivariate Cox proportional-hazard regression analysis for overall survival in PDAC patients undergoing resection

	Patients (%)	Univariable analysis		Multivariable analysis
		Hazard ratio	p	Hazard ratio	p
Age, ≥ 65	591 (43.75%)	1.23 (1.09-1.38)	0.001	1.13 (1.00-1.29)	0.057
Sex (male)	848 (62.77%)	1.05 (0.92-1.19)	0.468
Platelets, ≥ 200 × 109	561 (41.52%)	1.10 (0.98-1.25)	0.110
NLR, ≥ 3	470 (34.79%)	1.28 (1.12-1.45)	< 0.001	1.19 (1.05-1.36)	0.009
Albumin, < 40 g/L	742 (54.92%)	1.19 (1.05-1.34)	0.007	1.11 (0.98-1.26)	0.116
Obstructive jaundice	481 (35.60%)	1.16 (1.02-1.31)	0.025	0.94 (0.81-1.09)	0.424
D-dimer, ≥ 0.55 ng/mL	417 (30.87%)	1.47 (1.29-1.67)	< 0.001	1.33 (1.17-1.51)	< 0.001
CA19-9, ≥ 37 U/mL	1036 (76.68%)	1.40 (1.23-1.58)	< 0.001	1.25 (1.10-1.41)	0.001
Tumor location
Head	857 (63.43%)	Ref.
Body/tail	494 (36.57%)	0.97 (0.85-1.10)	0.639
Major vessel resection	191 (14.14%)	1.57 (1.33-1.86)	<0.001	1.08 (0.89-1.32)	0.419
Neural invasion	1155 (85.49%)	1.51 (1.26-1.81)	< 0.001	1.39 (1.15-1.67)	0.001
R1 resection, ≤ 1 mm	178 (13.18%)	1.51 (1.27-1.79)	< 0.001	1.39 (1.16-1.65)	< 0.001
T stage
T1-T2	843 (62.40%)	Ref.		Ref.
T3-T4	508 (37.60%)	1.57 (1.39-1.78)	< 0.001	1.54 (1.34-1.80)	< 0.001
N stage
N0	705 (52.18%)	Ref.		Ref.
N1-N2	646 (47.82%)	1.58 (1.40-1.79)	< 0.001	1.49 (1.31-1.69)	< 0.001
Differentiation
Well-moderate	1113 (82.38%)	Ref.		Ref.
Poor	238 (17.62%)	1.77 (1.52-2.06)	< 0.001	1.73 (1.48-2.02)	< 0.001
Adjuvant therapy	751 (55.59%)	0.61 (0.54-0.69)	< 0.001	0.61 (0.54-0.70)	< 0.001

PDAC, pancreatic ductal adenocarcinoma; NLR, neutrophil lymphocyte ratio; CA19-9, serum carbohydrate antigen 19-9

p value < 0.05 indicates statistical significance (in bold)