Endoscopic submucosal dissection for undifferentiated-type early gastric cancer: Do we have enough data to support this?

Table 4 Short-term outcomes of endoscopic resection for undifferentiated early gastric cancer n (%)

Study	LMP	VMP	LVI	En bloc resection	Complete resection	Curative resection	OP after ER1	Residual tumor2	LNM2	Bleeding	Perforation
Kim et al[80]	NA	NA	10 (12.5)	67 (90.5)	54 (73.0)	23 (31.1)	19/51 (37.3)	NA	NA	1 (1.4)	3 (4.1)
Abe et al[87]	5 (5.2)	4 (4.1)	3 (3.1)	96 (99.0)	88 (90.7)	62 (63.9)	21/35 (60.0)	1/21 (4.8)	2/21 (9.5)	4 (4.1)	4 (4.1)
Park et al[88]	12 (15.6)3		5 (6.5)	64 (83.1)	NA	35 (45.5)	11/42 (26.2)	NA	0/11 (0.0)	NA	NA
Okada et al[89]	5 (4.9)3		2 (2.0)	102 (99.0)	NA	85 (82.5)	10/18 (55.6)	2/10 (20.0)	0/10 (0.0)	9 (8.7)	1 (1.0)
Kamada et al[76]	5 (10.9)	4 (8.7)	4 (8.7)	42 (91.3)	NA	NA	5	1/5 (20.0)	NA	2/46 (4.3	2 (4.3)
Yamamoto et al[90]	1 (1.7)	0 (0.0)	2 (3.4)	57 (98.3)	52 (89.7)	46 (79.3)	8/12 (66.7)	2/8 (25.0)	0/8 (0.0)	5 (8.6)	2 (3.4)
Kang et al[73]	14 (23.3)	11 (18.3)	15 (25.0)	60 (100)	33 (55.0)	NA	15/27 (55.6)	6/15 (40.0)	2/15 (13.3)	1 (1.7)	1 (1.7
Kim et al[74]	10 (52.6)	9 (47.4)	NA	49 (84.5)	39 (67.2)	NA	9/19 (47.4)	4/9 (44.4)	1/9 (11.1)	8 (13.8)	1 (1.7)

¹Proportions are ratio of additional operation to incomplete or non-curative endoscopic resection;

²Data are the incidence of residual tumor or lymph node metastasis in specimens obtained by additional operation;

³Data are cases with lateral and/or vertical margin positivity. LMP: Lateral margin positivity; VMP: Vertical margin positivity; LVI: Lymphovascular invasion; OP: Operation; ER: Endoscopic resection; LNM: Lymph node metastasis; NA: Not available.