Table 4 Univariate and multivariate analyses of clinicopathological risk factors for neck failure

 N stage (pN+ vs pN0 & cN0/pNx^a)

4.491

0.888–22.717

0.069

–

–

NS

5.305

1.176–23.925

0.030

–

–

NS

 Extranodal extension (Yes vs No)

1.607

0.185–13.984

0.667

–

–

NS

11.479

2.519–52.305

0.002

6.018

1.203–30.104

0.029

 T stage (pT3–4 vs pT1–2)

5.102

0.903–28.819

0.065

–

–

NS

12.293

1.472–102.668

0.021

–

–

NS

 Lymphovascular invasion (Yes vs No)

3.738

0.751–18.597

0.107

–

–

NS

22.007

2.643–183.267

0.004

14.920

1.694–131.385

0.015

 Perineural invasion (Yes vs No)

63.645

0.089–45,483

0.215

–

–

NS

5.274

0.635–43.827

0.124

–

–

NS

 Margin (< 1 mm vs ≥ 1 mm)

1.860

0.217–15.951

0.571

–

–

NS

0.441

0.099–1.974

0.285

–

–

NS

 High-grade histology (Yes vs No)

24.834

0.001–872,589

0.548

–

–

NS

24.431

0.001–526,351.9

0.530

–

–

NS

 Ipsi. elective neck dissection (Yes vs No)

0.039

0.000–876.767

0.526

–

–

NS

–

–

–

–

–

–

 Ipsi. elective nodal irradiation (Yes vs No)

0.402

0.073–2.203

0.294

–

–

NS

–

–

–

–

–

–

 Cont. elective nodal irradiation (Yes vs No)

–

–

–

–

–

–

0.778

0.151–4.013

0.764

–

–

NS