Preoperative risk stratification of early recurrence in resected pancreatic ductal adenocarcinoma: Novel equilibrium-phase-computed tomography biomarker of extracellular volume

Table 1 Baseline characteristics of patients with pancreatic ductal adenocarcinoma, mean ± SD/n (%)

Characteristic	Non-ER (n = 47)	ER (n = 46)	P value
Age (years)	60.76 ± 1.50	61.27 ± 1.33	0.802
Male sex	29 (61.7)	29 (63.0)	0.867
Female sex	18 (38.3)	17 (37.0)	0.894
BMI (kg/m2), IQR	21.85 (20.50-23.93)	21.78 ± 4.70	0.895
Type of pancreatic surgery			0.165
Standard pancreatic surgery	42 (89.4)	37 (80.4)
Extended pancreatic surgery	5 (10.6)	9 (19.6)
Laboratory results
CA19-9 (U/mL), IQR	54.37 (15.48-268.88)	328.00 (90.45-500.00)	0.006
Haematocrit level (%), IQR	38.80 ± 7.86	38.00 (34.55-41.45)	0.339
Bilirubin (μmol/L), IQR	47.05 (12.98-159.25)	64.00 (10.20-201.55)	0.809
Albumin (g/L), IQR	40.50 (37.00-44.75)	38.97 ± 1.14	0.161
Lymphocytes (109/L), IQR	24.41 ± 1.38	19.50 (14.75-30.75)	0.207
Alkaline phosphatase (μkat/L), IQR	188.0 (88.0-428.0)	154.00 (87.00-461.00)	0.913
Tumor location			0.077
Head	31 (66.0)	37 (80.4)
Body/tail	16 (34.0)	9 (19.6)
Tumor size (cm), IQR	2.0 (1.50-3.50)	2.8 (2.25-3.90)	0.024
AJCC tumor stage			0.867
I	31 (66.0)	31 (67.4)
II/III	16 (34.0)	15 (32.6)
Tumor grade			0.006
G1/2	32 (68.1)	19 (41.3)
G3	15 (31.9)	27 (58.7)
Postoperative adjuvant therapy	26 (49.1)	27 (50.9)	0.430
ΔHUtumor, IQR	53.05 ± 3.43	37.00 (32.66-45.00)	0.003
CT-derived ECV (%)	39.78 ± 1.95	30.01 ± 1.90	0.001
CT findings of the pancreas
Ill-defined margins	13 (27.7)	13 (28.3)	0.948
Main pancreatic duct dilation	21 (44.7)	20 (43.5)	0.979
Parenchymal atrophy	7 (14.9)	11 (23.9)	0.271
Vein abutment	9 (19.1)	17 (37.0)	0.056
Peripancreatic tumor infiltration	11 (23.4)	18 (39.1)	0.102

ER: Early recurrence; IQR: Interquartile range; BMI: Body mass index; CA19-9: Carbohydrate antigen 19-9; ECV: Extracellular volume; HU: Hounsfield unit; ΔHU_tumor: Absolute enhancement of the tumor attenuation between the unenhanced and equilibrium-phase computed tomography images; CT: Computed tomography; AJCC: American Joint Committee on Cancer; G1: Well differentiated; G2: Moderately differentiated; G3: Poorly differentiated.