Factors associated with overall survival in early gastric cancer patients who underwent additional surgery after endoscopic submucosal dissection

Table 1 Characteristics of the patients

Clinicopathological factor	Total (n = 42)	Lymph node metastasis			Residual tumor
		No (n = 37)	Yes (n = 5)	P value	No (n = 29)	Yes (n = 13)	P value
Age (yr), n (%)				0.926			0.513
< 60	16 (38.1)	14 (37.8)	2 (40.0)		12 (41.4)	4 (30.8)
≥ 60	26 (61.9)	23 (62.2)	3 (60.0)		17 (58.6)	9 (69.2)
Sex (male), n (%)	35 (83.3)	34 (91.9)	1 (20.0)	< 0.001	26 (89.7)	9 (69.2)	0.101
Tumor location, n (%)				0.316			0.360
Upper stomach	12 (28.6)	12 (32.4)	0 (0)		9 (31.0)	3 (23.1)
Middle stomach	17 (40.5)	14 (37.9)	3 (60.0)		13 (44.8)	4 (30.8)
Lower stomach	13 (30.9)	11 (29.7)	2 (40.0)		7 (24.2)	6 (46.1)
Tumor size (cm), n (%)				0.281			0.862
< 2	9 (21.4)	7 (18.9)	2 (40.0)		6 (20.7)	3 (23.1)
≥ 2	33 (78.6)	30 (81.1)	3 (60.0)		23 (79.3)	10 (76.9)
Gross type, n (%)				0.207			0.106
Protruded	8 (19)	8 (21.6)	0 (0)		6 (20.7)	2 (15.4)
Flat	7 (16.7)	7 (18.9)	0 (0)		7 (24.1)	0 (0)
Pitting	27 (64.3)	22 (59.5)	5 (100.0)		16 (55.2)	11 (84.6)
Surgical method, n (%)				0.322			0.152
Distal subtotal gastrectomy	26 (61.9)	21 (56.8)	5 (100.0)		15 (51.7)	11 (84.6)
Proximal subtotal gastrectomy	8 (19)	8 (21.6)	0 (0)		6 (20.7)	2 (15.4)
Total gastrectomy	3 (7.2)	3 (8.1)	0 (0)		3 (10.3)	0 (0)
Celiac lymph node dissection	5 (11.9)	5 (13.5)	0 (0)		5 (17.3)	0 (0)
Invasion depth, n (%)				0.018			0.307
T1a	19 (45.2)	19 (51.4)	0 (0)		13 (44.8)	6 (46.2)
T1b	23 (54.8)	18 (48.6)	5 (100)		16 (55.2)	7 (53.8)
Histological type, n (%)				0.028			0.654
Differentiated	27 (64.3)	26 (70.3)	1 (20)		18 (62.1)	9 (69.2)
Undifferentiated	15 (35.7)	11 (29.7)	4 (80)		11 (37.9)	4 (30.8)
Number of tumor lesions, n (%)				0.710			0.498
Solitary	41 (97.6)	36 (97.3)	5 (100.0)		28 (96.6)	13 (100.0)
Multiple	1 (2.4)	1 (2.7)	0 (0)		1 (3.4)	0 (0)
Positive vascular invasion, n (%)	5 (11.9)	0 (0)	5 (100.0)	< 0.001	0 (0)	5 (38.5)	< 0.001
Lauren classification, n (%)				0.039			0.532
Intestinal type	22 (52.4)	21 (56.8)	1 (20.0)		15 (51.7)	7 (53.8)
Diffuse	13 (31.0)	9 (24.3)	4 (80.0)		8 (27.6)	5 (38.5)
Mixed	7 (16.6)	7 (18.9)	0 (0)		6 (20.7)	1 (7.7)
Pattern of invasion, n (%)				< 0.001			0.001
IFN-A	8 (19.0)	8 (21.6)	0 (0)		6 (20.7)	2 (15.4)
IFN-B	26 (62.0)	26 (70.3)	0 (0)		22 (75.9)	4 (30.8)
IFN-C	8 (19.0)	3 (8.1)	5 (100.0)		1 (3.4)	7 (53.8)
Positive horizontal resection margin, n (%)	19 (45.2)	18 (48.6)	1 (20.0)	0.227	10 (34.5)	9 (69.2)	0.036
Positive vertical resection margin, n (%)	21 (50.0)	16 (43.2)	5 (100.0)	0.017	14 (48.3)	7 (53.8)	0.739
Positive nerve invasion, n (%)	4 (9.5)	1 (2.7)	3 (60.0)	< 0.001	0 (0)	4 (30.8)	0.002
eCura score, n (%)				< 0.001			0.007
Low-risk group	24 (57.1)	24 (64.9)	0 (0)		18 (62.1)	6 (46.2)
Moderate-risk group	14 (33.3)	13 (35.1)	1 (20.0)		11 (37.9)	3 (23.1)
High-risk group	4 (9.6)	0 (0)	4 (80.0)		0 (0)	4 (30.7)
Degree of radical endoscopic treatment (eCura), n (%)				0.467			0.790
eCura-A	1 (2.4)	1 (2.7)	0 (0)		1 (3.5)	0 (0)
eCura-B	1 (2.4)	1 (2.7)	0 (0)		1 (3.5)	0 (0)
eCura-C1	11 (26.2)	11 (29.7)	0 (0)		7 (24.1)	4 (30.8)
eCura-C2	29 (69.0)	24 (64.9)	5 (100.0)		20 (68.9)	9 (69.2)
Ulcer, n (%)	26 (61.9)	22 (59.5)	4 (80.0)	0.375	16 (55.2)	10 (76.9)	0.180
Range of lymph node dissection, n (%)				0.409			0.101
D1	24 (57.1)	22 (59.5)	2 (40.0)		19 (65.5)	5 (38.5)
D2	18 (42.9)	15 (40.5)	3 (60.0)		10 (34.5)	8 (61.5)

Table 2 Independent risk factors for overall survival

Characteristic	Univariable analysis			Multivariable analysis
	HR	95%CI	P value	HR	95%CI	P value
Age (yr)
< 60	Reference	-	-	Reference	-	-
≥ 60	1.152	0.119-11.174	0.902
Sex (male)	13.550	1.407-130.515	0.024	21.906	3.762-229.250	0.039
Tumor location
Upper stomach	Reference	-	-	Reference	-	-
Middle stomach	2.740	0.563-13.340	0.212
Lower stomach	2.124	0.417-13.101	0.197
Tumor size (cm)
< 2	Reference	-	-	Reference	-	-
≥ 2	0.222	0.031-18.579	0.133
Gross type
Protruded	Reference	-	-	Reference	-	-
Flat	0.000	0.000	0.984
Pitting	1.440	0.149-27.959	0.753
Invasion depth
T1a	Reference	-	-	Reference	-	-
T1b	2.011	0.621-6.213	0.018	3.965	1.109-17.432	0.047
Histological type
Differentiated	Reference	-	-	Reference	-	-
Undifferentiated	13.155	0.991-25.014	0.028	9.455	0.946-29.482	0.049
Number of tumor lesions
Solitary	Reference	-	-	Reference	-	-
Multiple	0.912	0.301-9.761	0.781
Positive vascular invasion	0.818	0.169-8.965	0.803
Lauren classification
Intestinal type	Reference	-	-	Reference	-	-
Diffuse	1.683	0.518-15.468	0.386
Mixed	0.968	0.512-14.129	0.571
Pattern of invasion
IFN-A	Reference	-	-	Reference	-	-
IFN-B	0.545	0.080-33.730	0.537
IFN-C	9.899	1.159-19.526	0.036
Positive horizontal resection margin	0.989	0.164-45.987	0.990
Positive vertical resection margin	29.109	0.172-353.649	0.353
Positive nerve invasion	1.000	0.10-102.816	> 0.999
eCura score
Low-risk group	Reference	-	-	Reference	-	-
Moderate-risk group	0.938	0.126-27.910	0.810
High-risk group	0.994	0.108-10.192	0.715
Degree of radical endoscopic treatment (eCura)
eCura-A	Reference	-	-	Reference	-	-
eCura-B	0.997	0.000	> 0.999
eCura-C1	0.812	0.101-15.171	0.969
eCura-C2	1.745	0.257-11.846	0.569
Ulcer	0.829	0.134-13.122	0.840
Range of lymph node dissection
D1	Reference	-	-	Reference	-	-
D2	4.066	0.421-39.278	0.225
Lymph node metastasis	1.813	0.390-3.871	0.003	2.126	0.002-13.266	0.031
Residual tumor	5.160	2.391-9.107	0.021	4.275	1.049-27.420	0.043

HR: Hazard ratio; CI: Confidence interval.