Risk factors for local recurrence after en bloc endoscopic submucosal dissection for early gastric cancer

Table 1 Clinicopathologic feature of the 415 lesions treated with endoscopic submucosal dissection

	No. of lesions
	n = 415
Age, yr (mean ± SD)	64.2 ± 9.8
Sex, n (%)
Male	291 (70.1)
Female	124 (29.9)
Gross type of tumor, n (%)
Protruded (I)	29 (7.0)
Superficial elevated (IIa)	146 (35.2)
Flat (IIb)	76 (18.3)
Superficial depressed (IIc)	134 (32.3)
Excavated (III)	2 (0.5)
Mixed	28 (6.7)
En bloc resection, n (%)	415 (100)
Piecemeal resection, n (%)	0 (0)
Tumor location, n (%)
Upper	15 (3.6)
Mid	129 (30.9)
Lower	271 (65.0)
Tumor size, n (%)
≤ 20 mm	116 (28.0)
21-30 mm	77 (18.8)
31-40 mm	122 (29.4)
> 40 mm	100 (24.1)
Histology, n (%)
Well differentiated	195 (47.0)
Moderate differentiated	180 (43.4)
Poorly differentiated	30 (7.2)
Signet ring cell	10 (2.4)
Follow-up period, mo (mean ± SD)	19.7 ± 17.5

Table 2 Risk factor associated with neoplasia recurrence

	Recurrence	No recurrence	Univariate	Multivariate
	n = 36	n = 379	P value	P value
Age, yr (mean ± SD)	66.7 ± 9.0	64.0 ± 9.9	0.11
Male/female	25/11	266/113	0.93
Tumor margin, n (%)			0.02	0.03
Well-defined	24 (66.7)	313 (82.6)
Ill-defined	12 (33.3)	66 (17.4)
Tumor size, n (%)			0.62
≤ 20 mm	9 (25.0)	107 (28.2)
21-30 mm	6 (16.7)	71 (18.7)
31-40 mm	14 (38.9)	108 (28.5)
> 40 mm	7 (19.4)	93 (24.5)
Tumor location, n (%)			0.05
Upper	3 (8.3)	12 (3.2)
Mid	14 (38.9)	115 (30.3)
Lower	19 (52.8)	252 (66.5)
Histology, n (%)			0.7
Well differentiated	17 (47.2)	178 (47.0)
Moderate differentiated	13 (36.1)	167 (44.1)
Poorly differentiated	6 (16.7)	24 (6.3)
Signet ring cell	0 (0.0)	10 (2.6)
Procedure time, min (mean ± SD)	63.5 ± 56.9	48.8 ± 34.3	0.02	0.06
Safety margin, mm (mean ± SD)	3.1 ± 2.1	4.2 ± 2.9	0.03	0.05

Table 3 Factors associated with sufficient safety margin after endoscopic submucosal dissection (Univariate)

	Safety margin ≤1 mm	Safety margin > 1 mm	P value
	n = 63	n = 352
Age, yr (mean ± SD)	65.9 ± 11.1	63.9 ± 9.5	0.14
Male/female	38/25	253/99	0.12
Tumor margin, n (%)			0.52
Well-defined	53 (84.1)	284 (80.7)
Ill-defined	10 (15.9)	68 (19.3)
Tumor size, n (%)			0.55
≤ 20 mm	21 (33.3)	95 (27.0)
21-30 mm	12 (19.0)	65 (18.5)
31-40 mm	14 (22.2)	108 (30.7)
> 40 mm	16 (25.4)	84 (23.9)
Tumor location, n (%)			< 0.0001
Upper	7 (11.1)	8 (2.3)
Mid	31 (49.2)	98 (27.8)
Lower	25 (39.7)	246 (69.9)
Histology, n (%)			0.85
Well differentiated	32 (50.8)	163 (46.3)
Moderate differentiated	24 (38.1)	156 (44.3)
Poorly differentiated	3 (4.8)	27 (7.7)
Signet ring cell	4 (6.3)	6 (1.7)
Procedure time, min (mean ± SD)	58.9 ± 43.8	48.5 ± 35.4	0.04

Table 4 Factors associated with sufficient safety margin after endoscopic submucosal dissection (Multivariate)

	Multivariate analysis
	Odds ratio (95%CI)	P value
Location
Upper	2.90 (1.11-7.58)	0.03
Mid	1.10 (0.48-2.55)	0.82
Lower	1 (ref)
Ill-defined margin	2.32 (1.00-4.96)	0.03

Table 5 Neoplasia recurrence and cancer recurrence by safety margin 1 mm n (%)

	Safety margin ≤1 mm	Safety margin > 1 mm	P value
	n = 63	n = 352
Neoplasia recurrence	9 (14.3)	27 (7.7)	0.09
Cancer recurrence	4 (6.3)	2 (0.6)	0.006