Table 3 Univariate and multivariate analyses were performed using Cox’s proportional hazard model in patients with N3 gastric cancer

Age at diagnosis, y

79.168

< 0.001

  < 65

27.9

1

1

  ≥ 65

16.3

1.47 (1.35–1.60)

< 0.001

1.47 (1.35–1.60)

< 0.001

Gender

0.617

0.432

 Male

22.2

 Female

22.6

Ethnicity

80.923

< 0.001

 White

14.4

1

1

 Asian

27.4

0.66 (0.59–0.73)

< 0.001

0.66 (0.60–0.73)

< 0.001

 Black

15.8

1.02 (0.88–1.19)

0.781

1.03 (.88–1.20)

0.748

 Hispanic

21.4

0.85 (0.74–0.98)

0.028

0.84 (0.72–0.97)

0.014

 Native American

15.8

0.86 (0.52–1.42)

0.563

0.83 (0.50–1.36)

0.454

Histology

0.223

0.637

 G1/G2

22.7

 G3/G4

22.3

Tumor size, mm

17.131

< 0.001

  ≤ 60

24.6

1

1

  > 60

20.0

1.02 (0.94–1.12)

0.581

1.01 (0.93–1.10)

0.864

T-category

46.870

< 0.001

 T1

45.5

1

1

 T2

39.1

1.18 (0.79–1.75)

0.431

1.12 (0.75–1.67)

0.579

 T3

24.4

1.66 (1.18–2.34)

0.004

1.60 (1.14–2.26)

0.007

 T4a

20.3

1.86 (1.32–2.61)

< 0.001

1.77 (1.26–2.48)

0.001

 T4b

18.0

2.18 (1.54–3.10)

< 0.001

2.06 (1.45–2.93)

< 0.001

Type of surgery

1.255

0.263

 Proximal/distal gastrectomy

22.8

 Total gastrectomy

21.7

N-category

143.8

< 0.001

 N3a

28.3

1

1

 N3b

13.5

1.56 (1.43–1.70)

< 0.001

1.13 (0.99–1.29)

0.083

Modified N-category

157.67

< 0.001

 Modified N3a

30.7

1

 Modified N3b

14.5

1.51 (1.32–1.73)

< 0.001