Effect of lymphadenectomy extent on advanced gastric cancer located in the cardia and fundus

Table 1 Clinical characteristics of the 236 patients

Characteristics	n	Percentage
Gender
Male	197	83.5
Female	39	16.5
Age (yr)
< 60	103	43.6
≥ 60	133	56.4
Tumor size (cm)
< 3	88	37.3
3-6	97	41.1
> 6	51	21.6
Borrmann’s type
Type I, II	172	72.9
Type III, IV	64	27.1
Histological classification
Papillary adenocarcinomas	47	20
Tubular adenocarcinomas	101	42.8
Mucinous adenocarcinomas	29	12.3
Poorly differentiated adenocarcinomas	36	15.3
Undifferentiated carcinomas	8	3.4
Others	15	6.4
Depth of invasion (T category)
Muscularis (pT2)	25	10.6
Serosa (pT3)	118	50
Invasion to adjacent organs (pT4)	93	39.4
Lymph node involvement (N category)
pN0	42	17.8
pN1	97	41.1
pN2	68	28.8
pN3	29	12.3
Stage
II	48	20.3
III	128	54.2
IV	60	25.4
Type of gastrectomy
TG	190	80.5
PSG	46	19.5

Table 2 Multiple stepwise regression analysis with the Cox proportional hazards model (n = 236)

Characteristics	β	Wald	P	RR	95% CI
Result 1
Tumor size		8.40	0.015
3-6 cm vs < 3 cm	0.303	3.77	0.052	1.354	0.997-1.840
> 6 cm vs < 3 cm	0.530	7.88	0.005	1.699	1.174-2.460
pT category		37.34	0.000
T3 vs T2	0.899	13.51	0.000	2.457	1.522-3.969
T4 vs T2	1.498	33.55	0.000	4.471	2.693-7.420
Number of total LNs	-0.042	18.56	0.000	0.959	0.941-0.977
Number of positive LNs	0.094	53.05	0.000	1.098	1.071-1.126
Result 21
Tumor size		8.83	0.012
3-6 cm vs < 3 cm	0.299	3.67	0.055	1.349	0.993-1.833
> 6 cm vs < 3 cm	0.547	8.41	0.004	1.727	1.194-2.499
pT category		37.97	0.000
T3 vs T2	0.899	13.50	0.000	2.456	1.521-3.967
T4 vs T2	1.507	33.96	0.000	4.511	2.718-7.488
Number of positive LNs	0.052	20.20	0.000	1.053	1.030-1.077
Number of negative LNs	-0.045	19.69	0.000	0.956	0.938-0.975

¹Obtained by using number of negative LNs as the variable instead of number of total LNs.

Table 3 Five-year overall survival by stage subgroups and total number of LNs dissected

	< 15		15-19		20-24		25-29		≥30		P
	n	OS (%)	n	OS (%)	n	OS (%)	n	OS (%)	n	OS (%)
pTcategory
T2	4	25.0	8	50.0	9	55.6	3	33.3	1	0	0.2612
T3	20	13.8	23	22.6	25	45.1	24	37.0	26	48.5	0.6093
T4	12	4.6	12	7.5	28	13.5	13	23.1	28	37.5	0.0015
pNcategory
N0	8	15.0	10	41.7	11	60.0	8	62.5	5	40.0	0.2487
N1	16	8.7	15	13.3	24	37.8	15	52.9	27	40.7	0.0005
N2	12	7.7	17	8.3	19	12.5	10	25.0	10	30.0	0.0034
N3	NA		1	0	8	0	7	0	13	7.6	0.0016
Total	36	19.4	43	25.0	62	37.4	40	45.0	55	38.2	0.0009

NA: Not applicable; OS: Overall survival rate.

Table 4 Overall survival by total LN count, each stagesubgroup cut point analysis

Total LN count	Stage II		Stage III		Stage IV		Total
	χ2	P	χ2	P	χ2	P	χ2	P
7-14 vs≥ 15	0.17	0.6842	20.04	< 0.0001	4.36	0.0369	9.23	0.0024
≤ 19 vs≥ 20	5.22	0.0136	18.46	< 0.0001	8.70	0.0032	2.15	0.0425
≤ 24 vs≥ 25	0.27	0.6051	22.05	< 0.0001	9.07	0.0026	6.49	0.0109
≤ 29 vs≥ 30	1.20	0.2726	8.70	0.0032	13.70	0.0002	5.89	0.0153

Table 5 Overall five-year survival by stage subgroup and number of negative LNs

	0-9		10-19		20-29		≥30		Log-rank P value
	n	OS (%)	n	OS (%)	n	OS (%)	n	OS (%)
pTcategory
T2	4	0	15	47.1	6	83.3	NA		0.4907
T3	23	6.7	46	38.2	37	51.4	12	58.3	< 0.0001
T4	35	3.6	32	12.0	20	40.0	6	16.7	< 0.0001
pNcategory
N0	1	0	19	65.8	18	66.7	4	40.0	0.0317
N1	12	15.2	37	24.5	34	47.1	14	42.9	0.0328
N2	30	5.1	28	22.4	9	33.3	1	0	0.0055
N3	18	0	9	11.1	2	50.0	NA		0.0114
Total	61	4.8	93	33.8	63	53.9	19	45.0	< 0.0001

NA: Not applicable; OS: Overall survival rate.