Radiomics for predicting perineural invasion status in rectal cancer

Table 1 Baseline characteristics of the study population

Characteristics	PNI+ (n = 144)	PNI- (n = 159)	P value	The training set(n = 242)	The validation set(n = 61)	P value
Age (mean ± SD, yr)	58.9 ± 11.8	58.9 ± 11.7	0.952	58.4 ± 11.9	60.8 ± 10.2	0.162
Sex (male/female)	77/67	93/66	0.379	140/102	30/31	0.223
Volume (cm3)	19.7	20.8	0.132	20.1	20.8	0.847
Location1			0.075			0.045
Middle-low	101	96		164	33
High	43	63		78	28
cT stage (T1-2/T3/T4)	25/98/21	57/90/12	< 0.001	61/156/25	21/32/8	0.222
cN stage (N0/N1/N2)	31/52/61	75/59/25	< 0.001	89/84/69	17/27/17	0.313
Neoadjuvant therapy (+/-)	25/119	37/122	0.203	51/191	11/50	0.599
CEA (+/-) (positive ≥ 5 ng/mL)	77/67	56/103	0.001	107/135	26/35	0.823
CA19-9 (+/-) (positive ≥ 30 U/mL)	43/101	35/124	0.119	64/178	14/47	0.577
CA125 (+/-) (positive ≥ 24 U/mL)	20/124	15/144	0.226	20/222	3/58	0.378
pT stage (T1/T2/T3/T4)	0/15/117/12	8/44/95/12	< 0.001	6/48/171/17	2/11/41/7	0.584
pN stage (0/N1/N2)	29/74/41	81/56/22	< 0.001	88/101/53	22/29/10	0.579
Stage (Ⅰ/Ⅱ/Ⅲ)	10/28/115	38/43/78	< 0.001	40/48/154	8/14/39	0.731
Histologic grade (G1/G2/G3)	1/105/38	2/133/24	0.014	2/189/51	1/49/11	0.523
Rad-score	0.60 ± 0.19	0.40 ± 0.20	< 0.001	0.50±0.21	0.49 ± 0.23	0.805

¹Location: Low (0-5 cm from the anal verge), middle (5.1-10 cm from the anal verge), and high (10.1-15 cm from the anal verge). This table summarized the results of cT-stage and cN-stage for the two readers. CT: Computed tomography; PNI: Perineural invasion; CEA: Carcinoembryonic antigen; CA19-9: Carbohydrate antigen 19-9; CA125: Carbohydrate antigen 125; cT stage: Computed tomography-reported T stage; cN stage: Computed tomography-reported N stage; pT stage: Pathological T stage; pN stage: Pathological N stage.