Impact of tumor location on clinical outcomes of gastric endoscopic submucosal dissection

Table 1 Baseline characteristics of gastric tumors n (%)

Characteristic	Value
Gender (female:male)	1:2.18 (454:989)
Age, yr, mean ± SD	63.0 ± 9.4
Tumor size, mm
< 20	1034 (71.7)
≥ 20	409 (28.3)
Macroscopic appearance
Elevated	310 (21.5)
Flat	128 (8.9)
Depressed	90 (6.2)
Mixed	915 (63.4)
Ulcer	71 (4.9)
Invasion depth
Mucosa	612 (42.4)
Submucosa	106 (7.3)
LocationI
Lower third	1233 (85.4)
Middle third	112 (7.8)
Upper third	98 (6.8)
Location II
Anterior wall	294 (20.4)
Lesser curvature	481 (33.3)
Posterior wall	405 (28.1)
Greater curvature	263 (18.2)
Histology
Low grade dysplasia	534 (37.0)
High grade dysplasia	176 (12.2)
Differentiated EGC	655 (45.4)
Undifferentiated EGC	78 (5.4)
Procedure time, min	61.8 (± 47.0)
Curability
Complete resection	1287 (89.0)
Incomplete resection	156 (11.0)
Resectability
En bloc	1318 (91.3)
Piecemeal	125 (8.7)
Perforation	39 (2.7)
Post-ESD bleeding	63 (4.3)

EGC: Early gastric cancer; ESD: Endoscopic submucosal dissection.

Table 2 Comparison of the upper third and non-upper third groups n (%)

	Upper third	Non-upper third	Pvalue
Tumor size, mm
< 20	70 (71.4)	964 (71.7)	0.520
≥ 20	28 (28.6)	381 (28.3)
Ulcer	2 (2.0)	69 (5.1)	0.172
Pathology
Dysplasia	45 (45.9)	665 (49.4)	0.501
Carcinoma	53 (54.1)	680 (50.6)
Curability
Incomplete resection	19 (19.4)	137 (10.2)	0.005
Complete resection	79 (80.6)	1208 (89.8)
Resectability
En bloc	83 (84.7)	1235 (91.8)	0.015
Piecemeal	15 (15.3)	110 (8.2)
Procedure time, min, mean ± SD	90.51 ± 58.06	59.71 ± 45.46	< 0.001
Perforation	9 (9.2)	30 (2.2)	< 0.001
Post-ESD bleeding	4 (4.1)	57 (4.2)	0.600

ESD: Endoscopic submucosal dissection.

Table 3 Comparison of the posterior wall and non-posterior wall groups n (%)

	Posterior wall	Non-posterior wall	Pvalue
Tumor size, mm
< 20	278 (68.6)	756 (72.8)	0.065
≥ 20	127 (31.4)	282 (27.2)
Ulcer	21 (5.2)	50 (4.8)	0.771
Pathology
Dysplasia	216 (53.3)	494 (47.6)	0.053
Carcinoma	189 (46.7)	544 (52.4)
Procedure time, min, mean ± SD	69.41 ± 52.55	58.84 ± 44.39	< 0.001
Curability
Incomplete resection	60 (14.8)	96 (9.2)	0.002
Complete resection	345 (85.2)	942 (90.8)
Resectability
En bloc	358 (88.4)	960 (92.5)	0.013
Piecemeal	47 (11.6)	78 (7.5)
Perforation	14 (3.5)	25 (2.4)	0.27
Post-ESD bleeding	17 (4.2)	44 (4.2)	0.552

ESD: Endoscopic submucosal dissection.

Table 4 Multivariate analysis for incomplete resection

	Univariate analysis		Multivariate analysis
	OR (95%CI)	Pvalue	OR (95%CI)	Pvalue
Tumor size, mm
< 20	1 (reference)
≥ 20	2.144 (1.526-3.011)	< 0.001	1.846 (1.283-2.654)	0.001
Ulcer
-	1 (reference)
+	1.210 (0.589-2.485)	0.604
SM invasion
-	1 (reference)
+	1.828 (0.811-4.119)	0.146
Location
Non-upper third	1 (reference)
Upper third	2.12 1(1.247-3.607)	0.006	1.576 (0.882-2.814)	0.124
Location
Non-posterior wall	1 (reference)
Posterior wall	1.707 (1.208-2.410)	0.002	1.687 (1.163-2.449)	0.006
Pathology
Dysplasia	1 (reference)
Carcinoma	4.921 (3.240-7.475)	< 0.001	4.675 (3.049-7.166)	< 0.001
Procedure time, min
< 60	1 (reference)
≥ 60	2.494 (1.772-3.509)	< 0.001	1.648 (1.142-2.379)	< 0.001

SM: Submucosa.

Table 5 Multivariate analysis for perforation

	Univariate analysis		Multivariate analysis
	OR (95%CI)	Pvalue	OR (95%CI)	Pvalue
Tumor size, mm
< 20	1 (reference)
≥ 20	2.470 (1.304-4.678)	0.006	1.574 (0.807-3.071)	0.183
Ulcer
-	1 (reference)
+	1.637 (0.492-5.451)	0.422
SM invasion
-	1 (reference)
+	1.041 (0.238-4.550)	0.957
Location
Non-upper third	1 (reference)
Upper third	4.433 (2.042-9.623)	< 0.001	2.783 (1.138-6.803)	0.025
Location
Non-posterior wall	1 (reference)
Posterior wall	1.451 (0.746-2.820)	0.272
Pathology
Dysplasia	1 (reference)
Carcinoma	1.755 (0.905-3.405)	0.096
Procedure time, min
< 60	1 (reference)
≥ 60	8.143 (3.390-19.561)	< 0.001	4.985 (1.978-12.565)	< 0.001
Curability
Complete resection	1 (reference)
Incomplete resection	1.842 (0.799-4.248)	0.152
Resectability
En bloc	1 (reference)
Piecemeal	7.352 (3.748-14.423)	< 0.001	4.029 (1.987-8.170)	< 0.001

SM: Submucosa.

Table 6 Multivariate analysis for post-endoscopic submucosal dissection bleeding

	Univariate analysis		Multivariate analysis
	OR (95%CI)	Pvalue	OR (95%CI)	Pvalue
Tumor size, mm
< 20	1 (reference)
≥ 20	1.938 (1.151-3.362)	0.013	1.523 (0.886-2.619)	0.128
Ulcer
-	1 (reference)
+	1.377 (0.485-3.909)	0.547
SM invasion
-	1 (reference)
+	0.807 (0.276-2.358)	0.695
Location
Non-upper third	1 (reference)
Upper third	1.621 (0.957-2.745)	0.072
Location
Non-posterior wall	1 (reference)
Posterior wall	0.990 (0.559-1.754)	0.972
Pathology
Dysplasia	1 (reference)
Carcinoma	1.633 (0.963-2.770)	0.069
Procedure time, min
< 60	1 (reference)
≥ 60	2.804 (1.636-4.807)	< 0.001	2.120 (1.185-3.793)	0.011
Curability
Complete resection	1 (reference)
Incomplete resection	1.259 (0.587-2.698)	0.555
Resectability
En bloc	1 (reference)
Piecemeal	3.771 (2.040-6.971)	< 0.001	2.749 (1.433-5.276)	0.002

SM: Submucosa.