Endoscopic submucosal dissection for early gastric cancer with undifferentiated-type histology: A meta-analysis

Table 1 Clinical data of included studies

Ref.	Duration of follow up	Location, language	Complete resection	Curative resection	En bloc resection	Total recurrence	Adverse events	Total patients
Kim et al[23], 2009	Mean 17.1 ± 9.1 mo	South Korea (English)				1/32	Bleeding 6/32	32
Kang et al[24], 2010	Mean 16 mo	South Korea (English)	33/60		60/60	0/60	Bleeding 1/60 perforation 1/60	60
Lee et al[25], 2010	Median 13.5 mo	South Korea (English)		22/581	48/58	0/16 (3 yr) 0/2 (5 yr)		58
Yamamoto et al[26], 2010		Japan (English)		46/58	57/58		Bleeding 5/58 perforation 2/58	58
Goh et al[27], 2011	Mean 19.39 ± 11.2 mo	South Korea (English)	10/18			3/14		18
Park et al[28], 2012	Mean 41 mo	South Korea, multicenter (2) (English)		23/55				55
Kamada et al[29], 2012	Mean 3.8 yr	Japan (English)	37/46		42/46	1/462	Bleeding 2/46 perforation 2/46	46
Okada et al[30], 2012	Median 36 mo	Japan (English)		85/103	102/103		Bleeding 9/101 perforation 1/101	103
Park et al[31], 2013	Median 24.1 mo (absolute indication group), 30 mo (expanded indication group)	South Korea (English)	91/116		106/116		Bleeding 7/116 perforation 6/116	116
Choi et al[32], 2013	Mean 37.4 mo	South Korea (Korean)	66/82		72/82	3/823		82
Kim et al[33], 2013	Median 34 mo	South Korea, multicenter (6) (English)	54/74	23/74	67/74	4/74	Bleeding 1/74 perforation 3/74	74
Abe et al[34], 2013	Median 76.4 mo	Japan (English)	88/97	62/97	96/97	2/794	Bleeding 4/97 perforation 3/97 delayed perforation 1/97	97
Chung et al[35], 2014	Mean 41.7 ± 22.6 mo	South Korea (Korean)	58/76		64/76	9/64	Bleeding 4/76 perforation 0/76	76
Oka et al[36], 2014	Mean 101.9 ± 38.9 mo	Japan (English)	86/97	60/97			Bleeding 6/97 perforation 1/97	97

¹Curative resection was defined as RM (-), LVI (-), and lesions not deeper than SM 500 um;

²Seven patients who underwent operation after ESD were included;

³Patients who underwent operation or APC ablation were included;

⁴Nineteen patients who underwent operation after ESD were included. ESD: Endoscopic submucosal dissection.

Table 2 Clinical data of included studies (expanded indication)

Ref.	Complete resection	Curative resection	En bloc resection	Total recurrence	Total patients	Adverse events
Kang et al[24], 2010	17/18				18
Lee et al[25], 2010	11/17				17
Yamamoto et al[26], 2010	46/471	46/47	47/47		47	Bleeding 5/47 perforation 2/47
Park et al[28], 2012		23/55			55
Kamada et al[29], 2012	32/34				34
Okada et al[30], 2012		85/103	102/103		103
Park et al[31], 2013	91/116		106/116		116	Bleeding 7/116 perforation 6/116
Choi et al[32], 2013	66/82		72/82		82
Kim et al[33], 2013	23/29	23/29	25/29		29	Bleeding 0/29 perforation 2/29
Chung et al[35], 2014	50/58		51/58		58	Bleeding 4/76 perforation 0/76
Oka et al[36], 2014	57/60				60

¹Complete en bloc resection.

Table 3 Clinical data of included studies (expanded indication vs beyond expanded indication)

Ref.	Location, language	Complete resection				En bloc resection		Recurrence
		EI effective	EI total	Beyond EI effective	Beyond EI total	EI	Beyond EI	EI	Beyond EI
Kang et al[24], 2010	South Korea (English)	17	18	16	42	18/18	42/42	0/18	0/42
Lee et al[25], 2010	South Korea (English)	11	17	11	30
Yamamoto et al[26] 2010	Japan (English)	46	47	6	11	47/47	10/11
Kamada et al[29], 2012	Japan (English)	32	34	7	12			0/34	1/12
Kim et al[33], 2013	South Korea, multicenter (6) (English)	223	29	31	45			0/29	4/45
Chung et al[35], 2014	South Korea (Korean)	50	58	8	18	51/58	13/18
Oka et al[36], 2014	Japan (English)	57	60	29	37

Table 4 Methodological quality of included studies measured by Newcastle-Ottawa scale

Ref.	Selection	Comparability	Exposure or outcome	Total
Kim et al[23], 2009	4	1	2	7
Kang et al[24], 2010	4	1	2	7
Lee et al[25], 2010	4	2	2	8
Yamamoto et al[26], 2010	4	1	3	8
Goh et al[27], 2011	3	1	2	6
Park et al[28], 2012	3	1	3	7
Kamada et al[29], 2012	4	1	3	8
Okada et al[30], 2012	4		3	7
Park et al[31], 2013	4	2	2	8
Choi et al[32], 2013	4	2	3	9
Kim et al[33], 2013	4	1	3	8
Abe et al[34], 2013	4	1	3	8
Chung et al[35], 2014	3	2	3	8
Oka et al[36], 2014	3	1	3	7