Current indications for endoscopic submucosal dissection of early gastric cancer

Table 1 Absolute and expanded indications for endoscopic submucosal dissection in early gastric cancer patients in Japanese Gastric Cancer Association guideline version 4, 2014 and version 5, 2018

	T1a				T1b
	UL (-)		UL (+)		SM1 (< 500 µm)		SM2 (> 500 µm)
	≤ 2 cm	> 2 cm	≤ 3 cm	> 3 cm	≤ 3 cm	> 3 cm	≤ 3 cm	> 3 cm
JGCA guideline (version 4, 2014)
Differentiated	ESD	EXPANDED(JCOG0607)	EXPANDED(JCOG0607)	SURGERY	EXPANDED	SURGERY	SURGERY	SURGERY
Undifferentiated	EXPANDED	SURGERY	SURGERY	SURGERY	SURGERY	SURGERY	SURGERY	SURGERY
JGCA guideline (version 5, 2018)
Differentiated	ESD	ESD	ESD	SURGERY	EXPANDED	SURGERY	SURGERY	SURGERY
Undifferentiated	EXPANDED(JCOG1009/1010)	SURGERY	SURGERY	SURGERY	SURGERY	SURGERY	SURGERY	SURGERY

JGCA: Japanese Gastric Cancer Association; T1a: Mucosal carcinoma; T1b: Submucosal carcinoma; ESD: Endoscopic submucosal dissection absolute indication; EXPANDED: Endoscopic submucosal dissection expanded indication; SURGERY: Surgical indication; EGC: Early gastric cancer; UL (-): Without ulcer; UL (+): With ulcer; SM1: The submucosal invasion depth is less than 500 µm; SM2: The submucosal invasion depth is more than 500 µm.

Table 2 Curative and non-curative resection criteria for endoscopic submucosal dissection in early gastric cancer patients in Japanese Gastric Cancer Association guideline version 4, 2014 and version 5, 2018

	T1a				T1b
	UL (-)		UL (+)		SM1 (< 500 µm)		SM2 (> 500 µm)
	≤ 2 cm	> 2 cm	≤ 3 cm	> 3 cm	≤ 3 cm	> 3 cm	≤ 3 cm	> 3 cm
JGCA guideline (version 4, 2014)
Differentiated	CR	CR	CR	NCR	CR	NCR	NCR	NCR
Undifferentiated	CR	NCR	NCR	NCR	NCR	NCR	NCR	NCR
JGCA guideline (version 5, 2018)
Differentiated	eCura A	eCura A	eCura A	eCura C	eCura B	eCura C	eCura C	eCura C
Undifferentiated	eCura B	eCura C	eCura C	eCura C	eCura C	eCura C	eCura C	eCura C

JGCA: Japanese Gastric Cancer Association; T1a: Mucosal carcinoma; T1b: Submucosal carcinoma; UL (-): Without ulcer; UL (+): With ulcer; SM1: The submucosal invasion depth is less than 500 µm; SM2: The submucosal invasion depth is more than 500 µm; CR: Curative resection; NCR: Non-curative resection; eCura A and eCura B: The horizontal and vertical incisal margins were negative; eCura C: It means non-curative resection, which includes eCura C1 (non-en bloc resection or positive horizontal incisal margin) and eCura C2 (tumor diameter > 2 cm, undifferentiated or submucosal carcinoma).

Table 3 eCura system for predicting lymph node metastasis rate of non-curative resection in early gastric cancer

Risk factor	Score	Risk grade	Total score1	Lymph node metastasis rate (%)
Tumor diameter > 3 cm	1	Low	0-1	2.5
Submucosal invasion depth > 500 µm	1	Medium	2-4	6.7
Lymphatic invasion positive	3
Vascular invasion positive	1	High	5-7	22.5
Vertical incisal margin positive	1

¹Total score is the sum of the risk factor scores.

Table 4 Differences and correlations between eCura system and eCura in Japanese Gastric Cancer Association guidelines version 5 in early gastric cancer

	eCura system	eCura in JGCA guidelines version 5, 2018
Evaluation index	Predicting LNM	Curative resection criteria
Scope of application	Patients with EGC who do not meet the criteria of curative resection (eCura C2)	Patients with EGC who receive endoscopic resection
Category	Low risk; medium risk; high risk	eCura A; eCura B; eCura C1; eCura C2 (using eCura system predicted LNM rate)

JGCA: Japanese Gastric Cancer Association; LNM: Lymph node metastasis; EGC: Early gastric cancer.