Predictive value of magnetic resonance imaging parameters combined with tumor markers for rectal cancer recurrence risk after surgery

Table 1 Difference analysis between high recurrence risk group and low recurrence risk group

Variables	Total (n = 90)	LRR group (n = 53)	HRR group (n = 37)	Statistic	P value
Age (year), mean ± SD	64.92 ± 10.44	64.66 ± 10.98	65.30 ± 9.75	t = -0.28	0.778
Sex, n (%)				χ² = 1.79	0.180
Female	29 (32.22)	20 (37.74)	9 (24.32)	-	-
Male	61 (67.78)	33 (62.26)	28 (75.68)	-	-
BMI, mean ± SD	25.31 ± 2.90	25.08 ± 2.90	25.63 ± 2.92	t = -0.88	0.380
Smoking, n (%)				χ² = 0.37	0.541
No	65 (72.22)	37 (69.81)	28 (75.68)	-	-
Yes	25 (27.78)	16 (30.19)	9 (24.32)	-	-
Drinking, n (%)				χ² = 0.11	0.737
No	59 (65.56)	34 (64.15)	25 (67.57)	-	-
Yes	31 (34.44)	19 (35.85)	12 (32.43)	-	-
Family history, n (%)				χ² = 0.00	1.000
No	80 (88.89)	47 (88.68)	33 (89.19)	-	-
Yes	10 (11.11)	6 (11.32)	4 (10.81)	-	-
Complication, n (%)				χ² = 0.32	0.571
No	47 (52.22)	29 (54.72)	18 (48.65)	-	-
Yes	43 (47.78)	24 (45.28)	19 (51.35)	-	-
MTL, mean ± SD	3.98 ± 1.29	3.82 ± 1.30	4.22 ± 1.25	t = -1.48	0.141
Tumor location, n (%)				χ² = 0.48	0.787
Low	32 (35.56)	20 (37.74)	12 (32.43)	-	-
Median	39 (43.33)	23 (43.40)	16 (43.24)	-	-
High	19 (21.11)	10 (18.87)	9 (24.32)	-	-
MrT staging, n (%)				χ² = 2.81	0.094
I or II	46 (51.11)	31 (58.49)	15 (40.54)	-	-
III or IV	44 (48.89)	22 (41.51)	22 (59.46)	-	-
MrN staging, n (%)				χ² = 4.43	0.035
0 or I	46 (51.11)	32 (60.38)	14 (37.84)	-	-
II or III	44 (48.89)	21 (39.62)	23 (62.16)	-	-
CRM, n (%)				χ² = 8.25	0.004
Negative	38 (42.22)	29 (54.72)	9 (24.32)	-	-
Positive	52 (57.78)	24 (45.28)	28 (75.68)	-	-
EMVI, n (%)	-	-	-	χ² = 4.50	0.034
Negative	60 (66.67)	40 (75.47)	20 (54.05)	-	-
Positive	30 (33.33)	13 (24.53)	17 (45.95)	-	-
CEA, mean ± SD	40.08 ± 11.25	35.57 ± 9.31	46.55 ± 10.71	t = -5.17	< 0.001
CA125, mean ± SD	11.72 ± 5.25	11.07 ± 5.28	12.66 ± 5.13	t = -1.42	0.160
CA199, mean ± SD	56.58 ± 11.18	50.44 ± 7.85	65.39 ± 9.19	t = -8.29	< 0.001

BMI: Body mass index; LRR: Low recurrence risk; HRR: High recurrence risk; MTL: Maximum tumor length; CRM: Circumferential resection margin; EMVI: Extramural vascular invasion; CEA: Carcinoembryonic antigen; CA: Carbohydrate antigen.

Table 2 Univariate logistic regression analysis

Variables	β	SE	Z	P value	OR (95%CI)
Age	0.01	0.02	0.29	0.775	1.01 (0.97-1.05)
Sex
Female	-	-	-	-	1.00 (Reference)
Male	0.63	0.48	1.33	0.183	1.89 (0.74-4.80)
BMI	0.07	0.08	0.88	0.377	1.07 (0.92-1.24)
Smoking
No	-	-	-	-	1.00 (Reference)
Yes	-0.30	0.49	-0.61	0.542	0.74 (0.29-1.93)
Drinking
No	-	-	-	-	1.00 (Reference)
Yes	-0.15	0.45	-0.34	0.737	0.86 (0.35-2.09)
Family history
No	-	-	-	-	1.00 (Reference)
Yes	-0.05	0.68	-0.08	0.940	0.95 (0.25-3.63)
Complication
No	-	-	-	-	1.00 (Reference)
Yes	0.24	0.43	0.57	0.571	1.28 (0.55-2.96)
MTL	0.26	0.17	1.47	0.143	1.29 (0.92- 1.82)
Tumor location
Low	-	-	-	-	1.00 (Reference)
Median	0.15	0.49	0.30	0.762	1.16 (0.44-3.02)
High	0.41	0.59	0.69	0.490	1.50 (0.47-4.74)
MrT staging
I or II	-	-	-	-	1.00 (Reference)
III or IV	0.73	0.44	1.67	0.096	2.07 (0.88-4.85)
MrN staging
0 or I	-	-	-	-	1.00 (Reference)
II or III	0.92	0.44	2.08	0.037	2.50 (1.06-5.93)
CRM
Negative	-	-	-	-	1.00 (Reference)
Positive	1.32	0.47	2.80	0.005	3.76 (1.49-9.49)
EMVI
Negative	-	-	-	-	1.00 (Reference)
Positive	0.96	0.46	2.09	0.036	2.62 (1.06-6.43)
CEA	0.11	0.03	4.06	< 0.001	1.12 (1.06-1.18)
CA125	0.06	0.04	1.40	0.161	1.06 (0.98-1.15)
CA199	0.22	0.04	4.95	< 0.001	1.24 (1.14-1.35)

SE: Standard error; OR: Odds ratio; CI: Confidence interval; MTL: Maximum tumor length; MrT staging: Magnetic resonance based T staging; MrN staging: Magnetic resonance based N staging; CRM: Circumferential resection margin; EMVI: Extramural vascular invasion; CEA: Carcinoembryonic antigen; CA: Carbohydrate antigen.

Table 3 Multivariate logistic regression analysis

Variables	β	SE	Z	P value	OR (95%CI)	VIF
EMVI	-	-	-	-	-	-
Negative	-	-	-	-	1.00 (Reference)	-
Positive	1.46	0.72	2.01	0.045	4.29 (1.04-17.76)	2.31
CEA	0.07	0.04	2.04	0.041	1.08 (1.01-1.15)	1.60
CA125	0.18	0.08	2.13	0.034	1.19 (1.01-1.40)	1.32
CA199	0.24	0.06	3.95	< 0.001	1.27 (1.13-1.44)	1.49

SE: Standard error; OR: Odds ratio; CI: Confidence interval; VIF: Variance inflation factor; EMVI: Extramural vascular invasion; CEA: Carcinoembryonic antigen; CA: Carbohydrate antigen.

Table 4 Confusion matrix analysis of clinical predictive models

AUC (95%CI)	Accuracy (95%CI)	Sensitivity (95%CI)	Specificity (95%CI)	PPV (95%CI)	NPV (95%CI)	Cut off
0.93 (0.89-0.98)	0.83 (0.74-0.90)	0.74 (0.62-0.85)	0.97 (0.92-1.00)	0.98 (0.93-1.00)	0.72 (0.60-0.84)	0.145

AUC: Area under the curve; CI: Confidence interval; PPV: Positive predictive value; NPV: Negative predictive value.