Frequency and characteristics of synchronous gastric cancers: Need for improved awareness and better detection

Table 1 Prevalence and features of synchronous gastric neoplasms detected endoscopically

Ref.	Country	Study design	Setting and number of patients	Frequency and type of SGN, n (%)	Characteristics of synchronous neoplasm
Asonuma et al[10], 2024	Japan	Prospective multicenter	Patients undergoing ESD, 802	130 (16.2), EGC	Males: 81.5%
Shin et al[20], 2020	South Korea	Retrospective	Patients undergoing ESD/EMR, 1569	182 (11.6), cancer, adenoma	Age: 66.1 ± 8.0 years; males: 75.8%; location: Lower third 61.5%, middle third 34.6%, upper third 3.9%
Lim et al[19], 2015	South Korea	Retrospective	Patients undergoing ESD/EMR, 971	56 (5.8), EGC, HGD	Age: 64.5 (7.8) years; males: 78.6%. Location: Lower third 67.9%, middle third 28.6%, upper third 3.6%. Undifferentiated 7.1%
Gweon et al[14], 2015	South Korea	Retrospective	Patients undergoing EMR/ESD, 678	41 (6), cancer, dysplasia	Location: Upper third 7.3%, middle third 36.6%, lower third 56.1%. Morphology: Elevated 51.3%, flat 34.1%, depressed 14.6%
Park et al[15], 2014	South Korea	Retrospective	Patients undergoing ESD/EMR, 228	46 (20.1), EGC, HGD, LGD	Age: 66.1 ± 7.1 years; males: 71.7%. Morphology: Elevated 87%, protruding 8.7%, flat depressed 4.3%. Location: Lower third 61.4%, middle third 35.1%. Undifferentiated 2.2%
Kim et al[18], 2013	South Korea	Retrospective	Patients undergoing ESD, 602	38 (6.3), cancer, adenoma
Kim et al[9], 2013	South Korea	Retrospective multicenter	Patients undergoing ESD, 3018	275 (9.1), cancer, adenoma	Age: 67.4 years; males: 73.8%. Morphology: Elevated 53.1%, depressed 37.8%
Jang et al[17], 2013	South Korea	Retrospective	Patients who underwent ESD/EMR, 512	66 (12.9), EGC, adenoma
Kato et al[8], 2013	Japan	Retrospective multicenter	Patients who underwent ESD, 1258	110 (8.7)
Kasuga et al[7], 2013	Japan	Retrospective	Patients undergoing ESD, 851	62 (7.3), EGC	Age: 70.6 years; males: 71%. Location: Upper third 20%, middle third 40%, lower third 40%. Differentiated 96.8%

ESD: Endoscopic submucosal dissection; EMR: Endoscopic mucosal resection; EGC: Early gastric cancer; HGD: High-grade dysplasia; LGD: Low-grade dysplasia; SGN: Synchronous gastric neoplasm.