Lymph node metastasis in early gastric cancer with submucosal invasion: Feasibility of minimally invasive surgery

Table 1 Depth of submucosal invasion as compared with three SM category measurements

Depth (μm)	SM1 (%)	SM2 (%)	SM3 (%)
≤ 500 (n = 23)	19 (68)	4 (8)	0 (0)
500-1000 (n = 17)	8 (28)	8 (17)	1 (3)
1000-2000 (n = 19)	1 (4)	14 (30)	4 (13)
> 2000 (n = 46)	0 (0)	21 (45)	25 (84)
Total	28	47	30

Table 2 Relationship between clinicopathological factors and lymph node metastasis

	Total	Node-negative	Node-positive (n, %)	P
Sex
M	74	57	17 (23.0)	0.965
F	31	24	17 (22.6)
Age (yr)	105	54.8 ± 12.5	55.4 ± 12.2	0.822
Tumor location
Upper	1	1	0 (0)	0.614
Middle	53	42	11 (20.8)
Lower	48	35	13 (27.1)
Entire	3	3	0 (0)
Gross appearance
Elevated	23	15	8 (34.8)	0.055
Flat	6	3	3 (50.0)
Depressed	76	63	13 (17.1)
Tumor differentiation
Differentiated	47	35	12 (25.5)	0.557
Undifferentiated	58	46	12 (20.7)
Lauren’s classification
Intestinal	44	35	9 (20.5)	0.572
Diffuse	53	41	12 (22.6)
Mixed	8	5	3 (37.5)
Depth of invasion
SM1	28	24	4 (14.3)	0.448
SM2	47	35	12 (25.5)
SM3	30	22	8 (26.7)
Lymphatic invasion
Absence	86	69	17 (19.8)	0.109
Presence	19	12	7 (36.8)

Table 3 Lymph node status according to depth of invasion

Depth (μm)	Lymph node status (%)
	pN0	pN+	pN1	pN2
≤ 500 (n = 23)	21 (91)	2 (9)a	2	0
500-1000 (n = 17)	14 (82)	3 (18)	3	0
1000-2000 (n = 19)	15 (79)	4 (21)	3	1
> 2000 (n = 46)	31 (67)	15 (33)a	13	2

^aP < 0.05.

Table 4 Lymph node status according to tumor size

Size (cm)	Lymph node status (%)
	pN0	pN+	pN1	pN2
≤ 2 (n = 27)	24 (89)	3 (11)	3	0
2-3 (n = 30)	22 (73)	8 (27)	7	1
3-4 (n = 20)	15 (75)	5 (25)	5	0
> 4 (n = 28)	20 (71)	8 (29)	6	2

P = 0.403.

Table 5 Logistic regression analysis for factors associated with lymph node metastasis in submucosal gastric cancer

Variables	Odds ratio	95%CI	P-value
Depth of invasion (μm)
≤ 500	1
500-1000	2.02	0.30-13.86	0.473
1000-2000	3.14	0.49-20.24	0.228
> 2000	6.81	1.36-34.17	0.020
Tumor size (cm)
≤ 2	1
2-3	4.35	0.95-19.96	0.059
3-4	4.05	0.78-20.97	0.096
> 4	4.80	1.05-22.06	0.044

CI: Confidence interval.

Table 6 Lymph node status assessed by co-factor of size and depth in submucosal gastric cancer

Depth (μm)	Size (cm)
	≤ 2	2-3	3-4	> 4
≤ 500 (n = 23)	0a/4b	0/6	0/6	2/7
500-1000 (n = 17)	0/1	1/6	1/4	1/6
1000-2000 (n = 19)	0/5	2/8	1/2	1/4
> 2000 (n = 46)	3/17	5/10	3/8	4/11

^aNumber of cases with lymph node metastasis;

^bNumber of total cases.