Early gastric cancer: A challenge in Western countries

Table 1 Vienna classification

Category	Definition	Treatment
1	Negative for dysplasia/neoplasia	No treatment
2	Indefinite for dysplasia/neoplasia	Follow-up, recheck
3	Non-invasive, low-grade dysplasia	Follow-up
4	Non-invasive, high-grade dysplasia	Endoscopic resection, surgery
4.1	High-grade adenoma/dysplasia
4.2	Non-invasive carcinoma (CIS)
4.3	Suspicious of invasive carcinoma
5	Invasive neoplasia	Surgery (recently ESD)
5.1	Intramucosal carcinoma
M1	Mucosa only
M2	Mucosa with preservation of muscularis mucosae
M3	Not further than muscularis mucosae
5.2	Submucosal carcinoma or beyond
sm1	Invasion of muscularis mucosae < 0.5 µm
sm2	Invasion of muscularis mucosae > 0.5 µm

CIS: Cancer in situ; ESD: Endoscopic submucosal dissection.