Table 3 Multivariate Cox regression analysis of disease-specific survival ^a

Vessel involvement

0.667

  No

1.000

  Yes

0.868 (0.456 to 1.652)

Perineural invasion

0.205

  No

1.000

  Yes

1.555 (0.786 to 3.075)

Tumor grade

0.003

  T1

1.000

  T2

2.177 (0.474 to 6.841)

0.198

  T3

4.190 (0.733 to 10.148)

0.090

  T4

7.170 (1.909 to 15.503)

0.010

N stage

<0.001

  N0

1.000

  N1

1.315 (0.709 to 2.440)

0.385

  N2

2.366 (1.143 to 4.897)

0.020

  N3

16.474 (6.390 to 42.468)

<0.001

MLNR stage

<0.001

  MLNR0

1.000

  MLNR1

1.173 (0.625 to 2.203)

0.619

  MLNR2

2.678 (1.320 to 5.433)

0.006

  MLNR3

7.860 (3.695 to 16.718)

<0.001