Long-term outcomes of endoscopic resection for small (≤ 4.0 cm) gastric gastrointestinal stromal tumors originating from the muscularis propria layer

Table 1 Demographic and clinicopathologic features of 229 gastric MP-GISTs n (%)

Parameters	Endoscopic resection (n = 229)
Age (yr), mean ± SD	54.9 ± 10.8
Gender
Male	86
Female	143
Tumor size (cm), median (interquartile range)	1.90 (1.55-2.40)
Tumor location
Cardia	29 (12.7)
Fundus	118 (51.5)
Body	72 (32.1)
Antrum	10 (3.3)
Tumor growth pattern
Intraluminal growth	178 (77.7)
Extraluminal growth	51 (22.3)
EUS characteristics
Homogeneous echo	197 (86.0)
Inhomogeneous echo	32 (14.0)
Mitotic index
< 5/50 HPF	219 (95.6)
5-10/50 HPF	8 ( 3.5)
≥ 10/50 HPF	2 ( 0.9)
NIH risk classification
Very low	147 (64.2)
Low risk	72 (31.4)
Intermediate risk	8 ( 3.5)
High risk	2 ( 0.9)

EUS: Endoscopic ultrasonography.

Table 2 Risk factors associated with a high mitotic index (5/50 HPF) of gastrointestinal stromal tumors

	High mitotic index (> 5/50 HPF)
	Odds ratio	95%CI	P value
Age, yr (≤ 40, 40 to ≤ 60, and > 60)	-	-	0.756
Gender (male, female)	-	-	0.982
Tumor size, cm (< 2.0, 2.0-3.0, and ≥ 3.0)	6.675	2.047-21.771	0.002
Tumor location (cardia, fundus, body, and antrum)	-	-	0.505
Tumor growth pattern (intraluminal, extraluminal)	-	-	0.069

Table 3 Detailed information of studies evaluating endoscopic resection for gastric gastrointestinal stromal tumors

Author	Publication year	Study design	Case n	Endoscopic procedure	Tumor size, mean ± SD (cm)	Pathologic risk grade, n	Complete resection n (%)	surgical intervention n (%)	Recurrence n (%)	Follow-up (mo)
Feng et al[14]	2015	RS	50	Endoscopic resection	< 2	MI ≤ 5, 41 MI > 5, 9	NA	1 (2.0)	0	321 (12-65)
Shen et al[13]	2015	RS	32	ER	1.70 ± 0.36	Very low, 9 low, 18 intermediate, 3 high, 2	32 (100)	1 (3.1)	1 (3.1)	31.51 (2-53)
Joo et al[4]	2016	RS	90	ESD, 72 STER, 8 EMR, 7 EFTR, 2 Polypectomy, 1	2.3 ± 1.2	Very low, 45 Low, 28 Intermediate, 1 High, 6	88 (97.8)	5 (5.6)	2 (2.2)	46.0 ± 28.5
Tan et al[21]	2017	RS	52	STER, 20 EFTR, 32	STER, 17.8 ± 7.2; EFTR, 15.4 ± 6.6	Low, 26 Intermediate, 26	En bloc 50 (96.2)	1 (1.9)	1 (1.9)	10.9 ± 7.8 23.8 ± 18.6
An et al[11]	2017	RS	168	ESD	1.51 (0.5-6)	Very low, 117 Low, 37 Intermediate, 14	En bloc 168 (100)	0	0	251 (6-67)
Balde et al[18]	2017	RS	30	ESD	1.51 (1.0-1.8)	Very low, 22 Low, 4 Intermediate, 4	27 (90.0)	NA	2 (6.7)	57.9 (± 28.9)
Meng et al[19]	2017	RS	75	ESD	1.44 ± 0.67	NA	NA	NA	2 (2.7)	3.3 yr1 1-7 yr
Andalib et al[2]	2018	RS	12	EN, 5 EFTR, 7	2.41 (1.0 - 5.0)	Low, 11 Intermediate, 1	11 (91.7)	0	0	121 (6.5-24)
This study	-	RS	229	EME, 179 EFTR, 32 STER, 18	1.901 (1.0-4.0)	Very low, 147 Low, 72 Intermediate, 8 High, 2	221 (96.5)	1	0	571 (46-71)

¹Median. RS: Retrospective; ER: Endoscopic resection; ESD: Endoscopic submucosal dissection; STER: Submucosal tunneling endoscopic resection; EMR: Endoscopic mucosal resection; EN: Endoscopic enucleation; EME: Endoscopic muscularis excavation; EFTR: Endoscopic full-thickness resection; MI: Mitotic index.