Prognostic impact of dissected lymph node count on patients with node-negative gastric cancer

Table 1 Univariate analysis of variables in patients with node-negative gastric cancer

Characteristics	n	5-year survival rate (%)	χ2	P value
Gender			1.887	0.170
Male	164	81.7
Female	47	84.0
Age (yr)			0.619	0.431
< 60	109	84.2
≥ 60	102	79.9
Tumor size (cm)			4.538	0.033
≤ 4	94	88.9
> 4	117	76.8
Tumor location			1.681	0.432
Upper	75	80.1
Middle	40	81.7
Lower	96	84.0
Depth of invasion			27.698	0.000
T1	69	92.4
T2	58	83.9
T3	62	76.4
T4	22	57.8
Pathology			0.212	0.645
Differentiated	55	88.6
Undifferentiated	156	80.0
Surgical type			0.219	0.640
Total gastrectomy	99	80.5
Subtotal gastrectomy	112	83.6
Number of resected LNs			45.219	0.000
0-14	18	43.2
15-19	49	76.8
20-24	63	84.5
25-29	44	90.6
≥ 30	37	94.5

Table 2 Multiple stepwise regression analysis with the Cox proportional hazards model

Characteristics	β	SE	Wald	P	RR	95% CI
Tumor size (cm)	0.223	0.319	0.487	0.485	1.249	0.668-2.335
Depth of invasion			8.802	0.032
T2 vs T1	0.789	0.483	2.666	0.103	2.200	0.854-5.670
T3 vs T1	0.945	0.464	4.138	0.042	2.572	1.035-6.391
T4 vs T1	1.466	0.500	8.605	0.003	4.334	1.627-11.545
Number of resected LNs	-0.641	0.141	20.628	0.000	0.527	0.399-0.695

β: Coefficient of regression.

Table 3 Five-year overall survival by stage subgroups and total number of resected LNs n (%)

Depth of invasion	n	OS					P
		0-14	15-19	20-24	25-29	≥ 30
T1	69	4 (37.5)	19 (83.9)	20 (88.9)	17 (100.0)	9 (100.0)	0.003
T2	58	4 (25.0)	14 (70.1)	20 (89.4)	11 (90.9)	9 (100.0)	0.005
T3	62	7 (57.1)	12 (72.7)	19 (83.5)	10 (88.9)	14 (92.3)	0.022
T4	22	3 (33.3)	4 (75.0)	4 (50.0)	6 (66.7)	5 (80.0)	0.045
Total	211	18 (43.2)	49 (76.8)	63 (84.5)	44 (90.6)	37 (94.5)	0.000

OS: Overall 5-year survival rate.

Table 4 Overall survival by total LN count and cut-point analysis per each stage subgroup

Depth of invasion	≤ 14 vs ≥ 15		≤ 19 vs ≥ 20		≤ 24 vs ≥ 25		≤ 29 vs ≥ 30
	χ2	P	χ2	P	χ2	P	χ2	P
pT1-2	19.953	0.000	13.595	0.000	5.249	0.022	2.216	0.137
pT3-4	11.916	0.001	14.196	0.000	12.262	0.000	6.483	0.011
Total	32.824	0.000	26.679	0.000	16.109	0.000	7.572	0.006

Table 5 Impact of number of resected LNs on recurrence rate n (%)

Depth of invasion	No. of resected LNs	n	Recurrence rate2	r	P
pT1-2	0-14	8	5 (62.5)	-0.253	0.0011
	15-19	33	11 (33.3)
	20-24	40	8 (20.0)
	25-29	28	5 (17.8)
	≥ 30	18	1 (5.6)
pT3-4	0-14	10	8 (80.0)	-0.405	0.0001
	15-19	16	9 (56.2)
	20-24	23	8 (34.8)
	25-29	16	4 (25.0)
	≥ 30	19	3 (15.8)

¹Significance of differences was assumed at P < 0.01;

²Recurrence within 5 years after surgery.