Table 1.

Characteristics of the included studies.

ID	Country	Sample size	Study population	EUS type	Frequency (MHz)	ECG staging	Reference test
Kim et al. [16]	Korea	345	Confirmed ECG	Miniprobe	20	M, SM1, SM2	Surgery, ESD, or EMR
Cheng et al. [39]	China	205	Confirmed ECG	Radial	7.5 or 20	M, SM1, SM2	Surgery or ESD
Kim et al. [28]	Korea	273	Confirmed ECG	Miniprobe	20	M, SM	Surgery or ESD
Lee et al. [24]	Korea	393	Confirmed ECG	Radial	20	M, SM	Surgery, ESD, or EMR
Watari et al. [42]	Japan	132	Confirmed ECG	Miniprobe	20	M, SM1, SM2	Surgery, ESD, or EMR
Tsujii et al. [18]	Japan	208	Confirmed ECG	Miniprobe	12, 20	M, SM	Surgery or ESD
Mandai and Yasuda [34]	Japan	406	Confirmed ECG	Miniprobe or radial	20	M/SM1, SM2	Surgery, ESD, or EMR
Okada et al. [7]	Japan	542	Confirmed ECG	Miniprobe	20	M, SM1, SM2	Surgery or ESD
Choi et al. [23]	Korea	388	Confirmed ECG	Miniprobe	12	M, SM	Surgery or ESD
Kim et al. [12]	Korea	176	Suspected ECG	Miniprobe	20	M, SM	Surgery, ESD, or EMR
Mouri et al. [14]	Japan	235	Confirmed ECG	Miniprobe	20	M, SM	Surgery, ESD, or EMR
Kim et al. [9]	Korea	206	Suspected ECG	Miniprobe or radial	5, 7.5, 12, 15, 20	M, SM	Surgery or EMR
Akashi et al. [8]	Japan	267	Suspected EC	Miniprobe	12, 15, 20	M, SM	Surgery or EMR
Yoshida et al. [17]	Japan	295	Confirmed ECG	Miniprobe	7.5, 12, 15, 20	M, SM1, SM2	Surgery
Hizawa et al. [29]	Japan	234	Confirmed ECG	Miniprobe or radial	12, 20	M, SM	Surgery, ESD, or EMR
Matsumoto et al. [19]	Japan	78	Confirmed ECG	Miniprobe	20	M, SM	Surgery, ESD, or EMR
Ichikawa et al. [43]	Japan	142	Confirmed ECG	Miniprobe	12, 20, 30	M, SM1, SM2	Surgery or ESD

EMR: endoscopic mucosal resection; ESD: endoscopic submucosal dissection; EUS: endoscopic ultrasonography; M: mucosa; SM: submucosa.