Table 1 Cox proportional hazards model for overall survival in the elderly patients with resectable proximal gastric carcinoma from NCDB database

Age (per 1 SD)

1.05 (1.03–1.06)

<0.001

1.05 (1.03–1.07)

<0.001

 Female

Ref.

 Male

1.17 (1.06–1.29)

0.003

1.14 (1.00–1.29)

0.046

Race

0.20

 White

Ref.

–

 Black

1.05 (0.85–1.30)

0.63

–

 Asian

0.78 (0.58–1.04)

0.09

–

CDCI Score

<0.001

<0.001

 0

Ref.

Ref.

 1

1.28 (1.15–1.43)

<0.001

1.31 (1.14–1.51)

<0.001

 ≥ 2

1.77 (1.52–2.06)

<0.001

1.72 (1.41–2.08)

<0.001

Tumor size

<0.001

<0.001

 ≤ 2 cm

Ref.

Ref.

 2-4 cm

1.51 (1.31–1.75)

<0.001

1.23 (1.03–1.47)

0.02

 4-6 cm

1.93 (1.65–2.26)

<0.001

1.34 (1.10–1.64)

0.004

 >6 cm

2.19 (1.85–2.59)

<0.001

1.36 (1.10–1.68)

0.004

Differentiation grade

<0.001

0.005

 Well

Ref.

Ref.

 Moderately

1.36 (1.11–1.67)

0.003

1.01 (0.78–1.31)

0.94

 Poorly

1.94 (1.59–2.37)

<0.001

1.27 (0.98–1.65)

0.07

 Undifferentiated

1.74 (1.19–2.56)

0.005

1.18 (0.74–1.87)

0.50

Analytic TNM stage

<0.001

<0.001

 Stage 0-I

Ref.

Ref.

 Stage II

1.71 (1.50–1.94)

<0.001

1.36 (1.15–1.61)

<0.001

 Stage III

2.62 (2.33–2.95)

<0.001

2.24 (1.89–2.65)

<0.001

 No

Ref.

Ref.

 Yes

0.50 (0.44–0.57)

<0.001

0.66 (0.51–0.86)

0.002

 No

Ref.

–

 Yes

0.90 (0.80–1.01)

0.08

–

 No

Ref.

–

 Yes

1.00 (0.88–1.13)

0.98

–