D1: T1a cancer that is no indication for EMR/ESD

T1b, differentiated type, ≤1.5 cm, cN0

D1+: T1b, other than the above, cN0

D2: T1b, cN+

EMR: endoscopic mucosal resection

ESD: endoscopic submucosal dissection

cN0: clinically lymph node metastasis negative

cN+: clinically lymph node metastasis positive