Comparative detection of syndecan-2 methylation in preoperative and postoperative stool DNA in patients with colorectal cancer

Table 1 Characteristics of patients

	Patients with preoperative or postoperative stool sampling, n = 147 (%)	Patients with preoperative and postoperative stool sampling, n = 104 (%)
Sex
Male	97 (66.0)	66 (63.5)
Female	50 (34.0)	38 (36.5)
Age, yr
Mean (range)	62.3 (35-80)	62.8 (35-80)
Tumor location
Right colon	45 (30.6)	29 (27.9)
Left colon	62 (42.2)	51 (49.0)
Rectum	40 (27.2)	24 (23.1)
Histology
WD	6 (4.1)	4 (3.8)
MD	132 (89.8)	94 (90.4)
PD	9 (3.4)	5 (4.8)
Mucinous	4 (2.7)	1 (1.0)
Tumor size, cm
Mean (range)	3.7 (0.0-15.0)	3.5 (0.0-9.0)
T stage
Tis	5 (3.4)	4 (3.8)
T1	22 (15.0)	15 (14.4)
T2	27 (18.4)	19 (18.3)
T3	74 (50.3)	52 (50.0)
T4	19 (12.9)	14 (13.5)
N stage
N0	93 (63.3)	66 (63.5)
N+	54 (36.7)	38 (36.5)
TCF before surgery
Not done	14 (9.5)	9 (8.7)
Done	133 (90.5)	95 (91.3)
RAA
Not present	129 (87.8)	90 (86.5)
Present	18 (12.2)	14 (13.5)
Recurrence
No	137 (93.2)	98 (94.2)
Yes	10 (6.8)	6 (5.8)

WD: Well differentiated; MD: Moderately differentiated; PD: Poorly differentiated; TCF: Total colonoscopy; RAA: Remnant advanced adenoma.

Table 2 Demographic analysis of patients according to preoperative and postoperative syndecan-2 methylation test

Characteristics	Preoperative (n = 123)			Postoperative (n = 122)
	Negative, n = 14 (%)	Positive, n = 109 (%)	P value	Negative, n = 98 (%)	Positive, n = 24 (%)	P value
Sex			0.375			0.030
Male	11 (78.6)	69 (63.3)		68 (69.4)	11 (45.8)
Female	3 (21.4)	40 (36.7)		30 (30.6)	13 (54.2)
Age, yr			0.512			0.845
< 65	9 (64.3)	60 (55.0)		55 (56.1)	14 (58.3)
≥ 65	5 (35.7)	49 (45.0)		43 (43.9)	10 (41.7)
Location			0.664			0.079
Right colon	5 (35.7)	30 (27.5)		34 (34.7)	3 (12.5)
Left colon	7 (50.0)	51 (46.8)		42 (42.9)	12 (50.0)
Rectum	2 (14.3)	28 (25.7)		22 (22.4)	9 (37.5)
Histology			0.226			1.000
WD/MD	12 (85.7)	103 (94.5)		92 (93.9)	23 (95.8)
PD/Mucinous	2 (14.3)	6 (5.5)		6 (6.1)	1 (4.2)
Tumor size, cm			0.019			0.145
< 3	10 (71.4)	42 (38.5)		41 (41.8)	14 (58.3)
≥ 3	4 (28.6)	67 (61.5)		57 (58.2)	10 (41.7)
T stage			0.033			0.137
Tis-T2	9 (64.3)	34 (31.2)		33 (33.7)	12 (50.0)
T3-T4	5 (35.7)	75 (68.8)		65 (66.3)	12 (50.0)
N stage			0.769			0.152
N0	10 (71.4)	70 (64.2)		58 (59.2)	18 (75.0)
N+	4 (28.6)	39 (35.8)		40 (40.8)	6 (25.0)
TNM stage			0.769			0.152
0-II	10 (71.4)	70 (64.2)		58 (59.2)	18 (75.0)
III-IV	4 (28.6)	39 (35.8)		40 (40.8)	6 (25.0)
TCF before surgery			0.627			0.685
Not done	2 (14.3)	10 (9.2)		9 (9.2)	1 (4.2)
Done	12 (85.7)	99 (90.8)		89 (90.8)	23 (95.8)
RAA			0.692			0.172
Not present	13 (92.9)	94 (86.2)		88 (89.8)	19 (79.2)
Present	1 (7.1)	15 (13.8)		10 (10.2)	5 (20.8)

SDC2: Syndecan-2; WD: Well differentiated; MD: Moderately differentiated; PD: Poorly differentiated; TCF: Total colonoscopy; RAA: Remnant advanced adenoma.