Long-term outcomes of endoscopic submucosal dissection for undifferentiated type early gastric cancer over 2 cm with R0 resection

Table 2 Comparison between less than 2 cm and over 2 cm, n (%)

	Group A	Group B	P value
	Less than 2 cm (n = 51)	Over 2 cm (n = 28)
Age, yr, mean (SD)	49.84 ± 11.90	54.43 ± 12.71	0.114
Male sex	28 (54.9)	14 (50)	0.814
Location of tumor			0.567
Upper	3 (5.9)	1 (3.6)
Middle	28 (54.9)	19 (67.8)
Lower	20 (39.2)	8 (28.6)
Gross endoscopic appearance			0.148
Elevated	10 (19.6)	2 (7.1)
Flat	10 (19.6)	10 (35.7)
Depressed	31 (60.8)	16 (57.2)
Tumor size, cm, mean (SD)	1.06 ± 0.60	2.89 ± 0.58	< 0.001
≤ 2 cm	51 (100)	0 (0)
2.1-3 cm	0 (0)	19 (67.9)
> 3 cm	0 (0)	9 (32.1)
Depth of invasion			0.062
M1	0 (0)	0 (0)
M2	30 (58.8)	10 (35.7)
M3	21 (41.2)	18 (64.3)
Histology			0.630
Poorly differentiated adenocarcinoma	34 (66.7)	17 (60.7)
Signet ring cell carcinoma	17 (33.3)	11 (39.3)
Follow-up periods, months, mean (SD)	82.57 ± 43.62	74.51 ± 48.92	0.454

M1 epithelium, M2 lamina propria, M3 muscularis mucosa.