Long-term outcomes of endoscopic submucosal dissection and surgery for undifferentiated intramucosal gastric cancer regardless of size

Table 1 Baseline characteristics of the study population

Variables	Before matching			After matching
	ESD (n = 123)	Surgery (n = 562)	P value	ESD (n = 119)	Surgery (n = 119)	P value
Age, yr, mean SD	55.3 12.4	53.0 11.8	< 0.001	56.6 11.9	55.6 11.9	0.546
Male, n (%)	68 (55.3)	282 (50.2)	0.305	67 (56.3)	57 (47.9)	0.194
Comorbidity, n (%)
Hypertension	44 (35.8)	143 (25.4)	0.020	41 (34.5)	40 (33.6)	0.891
Diabetes	21 (17.1)	65 (11.6)	0.095	19 (16.0)	15 (12.6)	0.459
Cerebrovascular disease	8 (6.5)	18 (3.2)	0.113	7 (5.9)	2 (1.7)	0.171
Respiratory disease	7 (5.7)	29 (5.2)	0.811	6 (5.0)	6 (5.0)	-
Liver disease	3 (2.4)	26 (4.6)	0.275	3 (2.5)	3 (2.5)	-
Renal disease	2 (1.6)	4 (0.7)	0.294	1 (0.8)	1 (0.8)	-
ASA physical status1, n (%)			0.022			0.254
1	101 (82.1)	503 (89.5)		100 (84.0)	106 (89.1)
2	22 (17.9)	59 (10.5)		19 (16.0)	13 (10.9)
Tumor location, n (%)			< 0.001			0.822
Upper third	8 (6.5)	55 (9.8)		8 (6.7)	6 (5.0)
Middle third	97 (78.9)	321 (57.1)		93 (78.2)	93 (78.2)
Lower third	18 (14.6)	186 (33.1)		18 (15.1)	20 (16.8)
Lesion size, mm, n (%)			0.430			0.418
10	30 (24.4)	105 (18.7)		28 (23.5)	19 (16.0)
10-20	50 (40.7)	224 (39.9)		50 (42.0)	49 (41.2)
20-30	24 (19.5)	133 (23.7)		22 (18.5)	28 (23.5)
> 30	19 (15.4)	100 (17.8)		19 (16.0)	23 (19.3)
Gross morphology type1, n (%)			0.315			0.760
Elevated	33 (26.8)	127 (22.6)		29 (24.4)	27 (22.7)
Flat or depressed	90 (73.2)	435 (77.4)		90 (75.6)	92 (77.3)
Helicobacter pylori infection, n (%)	64 (51.2)	316 (56.2)	0.397	61 (51.3)	60 (50.4)	0.897
ESD indication, n (%)			0.183			0.183
Within expanded indication	80 (65.0)	329 (58.5)		78 (65.5)	68 (57.1)
Beyond expanded indication	43 (35.0)	233 (41.5)		41 (34.5)	51 (42.9)
Histology appearance, n (%)			< 0.001			0.794
Poorly differentiated carcinoma	56 (45.5)	151 (26.9)		52 (43.7)	54 (45.4)
Signet ring cell carcinoma	67 (54.5)	411 (73.1)		67 (56.3)	65 (54.6)

¹Physical status classification of the American Society of Anesthesiologists.

ESD: Endoscopic submucosal dissection; SD: Standard deviation.

Table 2 Clinical outcomes and adverse events of early gastric cancer resection according to treatment modality

Variables	ESD (n =119)	Surgery (n = 119)	P value
Median hospital stay, d (IQR)	4.0 (4.0-5.0)	9.0 (8.0-9.0)	< 0.001
ICU admission, n (%)	1 (0.8)	0 (0.0)	-
30-d readmission, n (%)	3 (2.5)1	2 (1.7)2	-
Operation-related death, n (%)	1 (0.8)	0 (0.0)	-
Complication, n (%)	14 (11.8)	7 (5.9)	0.110
Bleeding (early/late)	8/0	0/0
Perforation (early/late)	5/0	N/A
Pneumonia (early/late)	1/0	0/0
Anastomosis site leakage (early/late)	N/A	1/0
Adhesion or bowel obstruction (early/late)	0/0	1/2
Hernia (early/late)	N/A	1/2

¹All cases were bleeding.

²Vomiting owing to anastomosis site stricture, and pain owing to hernia.

Early and late complications occurred within or later than 30 days after operation or procedure, respectively. ESD: Endoscopic submucosal dissection; ICU: Intensive care unit; IQR: Interquartile range; N/A: Not applicable.

Table 3 Incidence and characteristics of recurrent tumors after initial treatment (endoscopic submucosal dissection or surgery)

Variables	ESD (n = 119)	Surgery (n = 119)	P value
Recurrence, n (%)	7 (5.9)	2 (1.7)	0.171
Local recurrence	4 (3.4)	N/A
Adenoma	0 (0.0)	N/A
Cancer	4 (3.4)	N/A
Differentiated	3 (2.5)	N/A
Undifferentiated	1 (0.8)	N/A
Synchronous lesion	0 (0.0)	1 (0.8)
Adenoma	0 (0.0)	0 (0.0)
Cancer	0 (0.0)	1 (0.8)
Differentiated	0 (0.0)	0 (0.0)
Undifferentiated	0 (0.0)	1 (0.8)
Metachronous lesion	3 (2.5)	0 (0.0)
Adenoma	1 (0.8)	0 (0.0)
Cancer	2 (1.7)	0 (0.0)
Differentiated	1 (0.8)	0 (0.0)
Undifferentiated	1 (0.8)	0 (0.0)
Distant metastasis	0 (0.0)	1 (0.8)

ESD: Endoscopic submucosal dissection; N/A: Not applicable.

Table 4 Clinical and tumor information for recurrent patients

Age	Sex	Location	Size (mm)	Morphology	Histology	Initial treatment	Recurrence type	Pathology of recurred lesion	Recurrence location	Recurrence time (mo)	Treatment for recurred lesion
61	F	Middle 1/3	6	Flat	SRC	ESD	Metachronous lesion	Undifferentiated cancer	Lower 1/3	70	ESD
62	M	Middle 1/3	22	Flat	SRC	ESD	Local recurrence	Undifferentiated cancer	Middle 1/3	6	Surgery
68	F	Middle 1/3	68	Flat	PDA	ESD	Metachronous lesion	Differentiated cancer	Upper 1/3	50	ESD
46	M	Middle 1/3	60	Flat	PDA	ESD	Local recurrence	Differentiated cancer	Middle 1/3	3	Surgery
50	F	Middle 1/3	25	Depressed	PDA	ESD	Local recurrence	Differentiated cancer	Middl1 1/3	12	ESD
62	M	Middle 1/3	40	Elevated	PDA	ESD	Local recurrence	Differentiated cancer	Middle 1/3	6	Surgery
56	F	Lower 1/3	8	Flat	PDA	ESD	Metachronous lesion	Adenoma	Middle 1/3	23	ESD
66	M	Lower 1/3	15	Flat	PDA	Surgery	Synchronous lesion	Undifferentiated cancer	Upper 1/3	5	Surgery
64	M	Middle 1/3	10	Elevated	SRC	Surgery	Distant metastasis	Undifferentiated cancer	Peritoneum	122	Conservative care

ESD: Endoscopic submucosal dissection; PDA: Poorly differentiated adenocarcinoma; SRC: Signet ring cell carcinoma.

Table 5 Cox proportional hazard model for risk of recurrence after initial treatment

Variables	Adjusted hazard ratio (95% confidence interval)	P value
Treatment modality
Surgery	1.0
ESD	5.2 (1.0-25.8)	0.045
Indication with any treatment modality
Within expanded indication	1.0
Beyond expanded indication	1.4 (0.4-5.4)	0.585
Indication with ESD
ESD for the lesion within expanded indication	1.0
ESD for the lesion beyond expanded indication	2.8 (0.6-12.4)	0.183

ESD: Endoscopic submucosal dissection.