Prognostic impact of metastatic lymph node ratio on gastric cancer after curative distal gastrectomy

Table 1 Clinical parameters of patients included in this study n (%)

Characteristics	Patients (n = 634)
Gender
Male	467 (73.6)
Female	167 (26.4)
Age (yr)	56.1 ± 12.1
Tumor size (cm)	4.3 ± 1.7
Tumor location
Lower	521 (80.8)
Middle	71 (11.2)
Lower and middle	42 (8.0)
Digestive tract construction
Billroth I	469 (74.0)
Billroth II	148 (22.3)
Roux-en-Y	17 (3.7)
Pathology
Differentiated	140 (22.1)
Undifferentiated	494 (77.9)
Depth of invasion
pT1	118 (18.6)
pT2	174 (27.4)
pT3	342 (54.0)
pN category
pN0	195 (30.8)
pN1	232 (36.6)
pN2	156 (24.6)
pN3	51 (8.0)
rN category
rN0	195 (30.8)
rN1	172 (27.1)
rN2	156 (24.6)
rN3	111 (17.5)
Number of resected LNs	23.1 ± 8.6

Table 2 Univariate analysis of variables for gastric cancer patients after curative distal gastrectomy

Parameters	n	5-yr survival (%)	χ2	P
Gender			< 0.001	0.991
Male	467	58.1
Female	167	56.3
Age (yr)			0.641	0.423
< 60	370	58.9
≥ 60	264	56.0
Tumor size (cm)			4.409	0.036
≤ 4	343	61.0
> 4	291	53.6
Tumor location			5.693	0.058
Lower	521	57.7
Middle	71	63.7
Lower and Middle	42	45.4
Digestive tract construction			5.508	0.064
Billroth I	469	60.7
Billroth II	148	48.5
Roux-en-Y	17	51.0
Pathology			9.135	0.003
Differentiated	140	68.1
Undifferentiated	494	54.6
Depth of invasion			70.466	0.000
pT1	118	90.6
pT2	174	64.4
pT3	342	42.9
pN category			142.279	0.000
pN0	195	83.3
pN1	232	59.3
pN2	156	33.9
pN3	51	20.0
rN category			217.494	0.000
rN0	195	83.3
rN1	172	68.6
rN2	156	40.7
rN3	111	17.2

Table 3 Multiple stepwise regression analysis with the Cox proportional hazards model

Parameters	β	SE	Wald	P	RR	95% CI
rN excluded
Tumor size	-0.025	0.117	0.045	0.832	0.976	0.776-1.227
Pathology	0.000	0.161	0.000	0.999	1.000	0.730-1.370
Depth of invasion			27.144	0.000
pT2 vs pT1	0.956	0.259	13.59	0.000	2.601	1.565-4.325
pT3 vs pT1	1.253	0.247	25.668	0.000	3.500	2.156-5.683
pN category			20.572	0.000
pN1 vs pN0	0.556	0.188	8.754	0.003	1.734	1.206-2.519
pN2 vs pN0	0.829	0.203	16.673	0.000	2.291	1.539-3.410
pN3 vs pN0	1.02	0.248	16.916	0.000	2.772	1.705-4.507
rN included
Tumor size	-0.033	0.117	0.078	0.779	0.968	0.769-1.218
Pathology	0.011	0.161	0.005	0.945	1.011	0.738-1.385
Depth of invasion			24.388	0.000
pT2 vs pT1	0.908	0.263	11.974	0.001	2.48	1.483-4.149
pT3 vs pT1	1.206	0.252	22.827	0.000	3.34	2.036-5.477
rN category			17.927	0.000
rN1 vs rN0	0.502	0.199	6.349	0.012	1.651	1.118-2.440
rN2 vs rN0	0.842	0.205	16.928	0.000	2.322	1.554-3.468
rN3 vs rN0	0.867	0.234	13.758	0.000	2.380	1.505-3.763

Table 4 Comparison of survival rates for patients classified by rN category or by pN category

N stage	n	rN1		rN2		rN3		P
		n	OS (%)	n	OS (%)	n	OS (%)
pN1	232	169	68.6	54	36.3	9	22.2	0.000
pN2	156	3	66.7	95	40.8	58	20.4	0.007
pN3	51	NA	NA	7	57.4	44	11.6	0.012

OS: Overall 5-year survival rate; NA: Not applicable.

Table 5 Comparison of survival rates for patients classified by pN category or by rN category

N stage	n	pN1		pN2		pN3		P
		n	OS (%)	n	OS (%)	n	OS (%)
rN1	147	169	68.6	3	66.7	NA	NA	0.638
rN2	156	54	36.3	95	40.8	7	57.4	0.188
rN3	51	9	22.2	58	20.4	44	11.6	0.257