Table 1.

Characteristics of patients in the training and testing cohorts

Characteristics	Training cohort (n = 99)			Testing cohort (n = 41)
	With PNI (n = 23)	Without PNI (n = 76)	P value	With PNI (n = 9)	Without PNI (n = 32)	P value
Age, mean ± SD, years	63 ± 14	66 ± 9	0.400	66 ± 10	63 ± 9	0.421
Gender (%)			0.891			0.092
Male	14 (60.9%)	45 (59.2%)		8 (88.9%)	22 (68.8%)
Female	9 (39.1%)	31 (40.8%)		1 (11.1%)	10 (31.2%)
CEA, median (P25, P75), ng/mL	3.00 (1.16,4.80)	3.29 (1.87,7.12)	0.249	5.10 (3.46,18.87)	2.89 (1.76,8.61)	0.127
CA199, median (P25, P75), ng/mL	9.65 (5.30,15.83)	12.42 (7.55,18.76)	0.335	10.77 (6.71,20.65)	14.26 (8.42,21.51)	0.496
Histologic grade			0.078			0.025
Well differentiated	1 (4.3%)	15 (19.7%)		0 (0)	5 (15.6%)
Moderately differentiated	18 (78.3%)	53 (69.7%)		6 (66.7%)	25 (78.1%)
Poorly differentiated	4 (17.4%)	8 (10.5%)		3 (33.3%)	2 (6.3%)
Primary site			0.763			0.464
Low	8 (34.8%)	28 (36.8%)		1 (11.1%)	8 (25.0%)
Mid	9 (39.1%)	31 (40.8%)		3 (33.3%)	10 (31.3%)
High	6 (26.1%)	17 (22.4%)		5 (55.6%)	14 (43.7%)
Longest diameter, mean ± SD, cm	5.71 ± 2.20	4.71 ± 1.97	0.041	5.22 ± 1.27	4.64 ± 1.90	0.161
mT-stage			< 0.00			0.089
T1/T2	6 (26.1%)	55 (72.4%)	1	4 (44.4%)	24 (75.0%)
T3	17 (65.4%)	21 (27.6%)		5 (55.6%)	8 (25.0%)
mLN-status			0.187			0.507
N0	10 (43.5%)	45 (59.2%)		7 (77.8%)	21 (65.6%)
N1-N2	13 (56.5%)	31 (40.8%)		2 (22.2%)	11 (34.4%)
CRM			0.149			0.023
Positive	9 (39.1%)	18 (23.7%)		6 (66.7%)	8 (25.0%)
Negative	14 (60.9%)	58 (76.3%)		3 (33.3%)	24 (75.0%)
EMVI			0.008			0.637
Positive	11 (47.8%)	15 (19.7%)		3 (33.3%)	8 (25.0%)
Negative	12 (52.2%)	61 (80.3%)		6 (66.7%)	24 (75.0%)

P-value for each radiomic feature associated with PNI was calculated using Wilcoxon test

Abbreviations: PNI perineural invasion, CEA carcinoembryonic antigen, CA19–9 carbohydrate antigen 19–9, mT-stage MRI reported T-stage, mLN-status MRI lymph node-status, CRM circumferential resection margin, EMVI extramural vascular invasion