Table 2 Results of univariate and multivariate analysis of potential prognostic factors in the training cohort

Race

 White

Reference

Reference

 Black

2.322(1.510–3.571)

 < 0.001

1.992(1.286–3.085)

0.002

 Other

0.623(0.270–1.440)

0.268

0.607(0.262–1.405)

0.244

Sex

 Female

Reference

 Male

1.145(0.772–1.700)

0.501

Age

 ≤ 35

Reference

Reference

 > 35

0.560(0.333–0.944)

0.030

0.696(0.407–1.192)

0.187

Marital status

 Married

Reference

Reference

 Unmarried/NOS

2.340(1.551–3.529)

< 0.001

1.888(1.239–2.879)

0.003

Tumor site

 Right

Reference

 Left

1.056(0.712–1.568)

0.786

Grade

 Grade I

Reference

Reference

 Grade II

1.186(0.571–2.463)

0.648

0.969(0.463–2.029)

0.934

 Grade III

1.476(0.603–3.610)

0.394

0.993(0.398–2.477)

0.988

 Grade IV

4.891(1.886–12.679)

0.001

2.509(0.938–6.714)

0.067

Tumor size (cm)

 ≤ 5

Reference

Reference

 > 5

1.544(1.043–2.287)

0.030

1.081(0.713–1.639)

0.714

T

 T1

Reference

Reference

 T2

2.107(0.957–4.642)

0.064

2.119(0.957–4.688)

0.064

 T3

2.407(1.247–4.647)

0.009

2.224(1.119–4.421)

0.023

 T4

7.775(3.883–15.571)

< 0.001

6.358(2.849–14.190)

< 0.001

Chemotherapy

 Yes

Reference

Reference

 No/unknown

0.485(0.323–0.730)

0.001

1.055(0.640–1.738)

0.834