Stage	Stratification	Grade I recommendations	Grade II recommendations
cT1aN0M0, Stage I	Patients suitable for EMR/ESD a	EMR/ESD (Evidence 1B) Patients who had non‐radical resection with EMR/ESD must be re‐operated (Evidence 1A) b	Patients with non‐radical resection must receive additional ESD, electrotomy or close follow‐up upon providing informed consent (Evidence 2A)

Abbreviations: EMR, endoscopic mucosal resection; ESD, endoscopic sub‐mucosal dissection; cTNM, clinical tumor‐node‐metastasis.

Notes

^a Principles of EMR/ESD for early gastric cancer

Endoscopic resection of early gastric cancer mainly includes EMR and ESD. In principle, endoscopic therapy is suitable for tumors with the least risk of lymph node metastasis [35]. The initial absolute indications for endoscopic resection were previously identified as well‐differentiated tumors limited to mucosa invasion (T1a) with a diameter <2 cm and without ulceration. Following the publication of the results of a Japanese multicenter prospective single‐arm study (JCOG0607) [36], the 5th edition of the Japanese Gastric Cancer Guidelines [37] expanded the indications for EMR and ESD to differentiated cancers invading the mucosal layer with diameter <2 cm (cT1a) and without ulcerations; and expanded indications for ESD to differentiated cancers of diameter >2 cm without ulceration invading the intramucosal layer (cT1a), and differentiated cancers of diameter <3 cm with ulceration and invading the intramucosal layer (cT1a). The expanded indications for ESD include undifferentiated non‐ulcerated intramucosal carcinoma (cT1a) with diameter <2 cm, patients with lesions classified as C1 (eCura evaluation system) following initial ESD or EMR, or cT1a following endoscopic evaluation after local recurrence, and for early gastric cancer patients aged >75 years or on anticoagulant therapy. For the Chinese gastric cancer population, the clinical implications of the expanded indications are still being investigated in many centers across China.

^b Evaluation and curative strategies for endoscopic radical resection.

The radicality of endoscopic resection is based on the extent of local resection and the possibility of lymph node metastasis. Results of large‐scale case studies and systematic analyses showed that for cases with absolute indications and negative margins, the rate of lymph node metastasis was <1% and had a long‐term prognosis similar to surgical resection. For cases satisfying the expanded criteria, the rate of lymph node metastasis was <3%, but long‐term follow‐up data are awaited [36, 38, 39].

The radicality of endoscopic resection should be confirmed using the resected specimen on the postoperative pathological report, based on which the necessity of further treatment and follow‐up are to be determined.