Table 2 Multivariate analysis of prognostic factors

Disease-free survival

 Sex

1.55

0.39–6.07

0.526

 Age

2.04

0.76–5.48

0.157

 N stage

3.38

1.12–10.28

0.029*

 Histological type

2.89

0.88–9.53

0.08

 Treatment

0.96

0.38–2.46

0.934

 Radiation dose

1.48

0.55–3.94

0.435

 Tumor volume

1.69

0.62–4.59

0.307

 Number of CN palsy symptom

1.92

0.69–5.28

0.205

 Initial TN symptom

0.86

0.21–3.59

0.85

 Initial AN symptom

0.95

0.16–5.65

0.963

 Initial ON symptom

0.41

0.02–6.98

0.54

 1-year recovery rate of TN palsy

3.05

0.68–5.28

0.205

 1-year recovery rate of AN palsy

0.63

0.07–5.1

0.665

 1-year recovery rate of ON palsy

3.91

0.24–63.48

0.34

Overall survival

 Sex

0.87

0.16–4.55

0.86

 Age

3.76

1.11–12.79

0.034*

 N stage

4.476

1.02–19.73

0.048*

 Histological type

2.98

0.78–11.44

0.111

 Treatment

2.57

0.82–8.04

0.106

 Radiation dose

0.943

0.27–3.29

0.926

 Tumor volume

3.501

0.9–13.61

0.071

 Number of CN palsy symptom

1.162

0.28–4.85

0.837

 Initial TN palsy symptom

0.743

0.14–3.94

0.728

 Initial AN palsy symptom

0.487

0.04–5.62

0.564

 Initial ON palsy symptom

0.286

0.01–10.02

0.49

 1-year recovery rate of TN palsy

2.59

0.43–15.56

0.295

 1-year recovery rate of AN palsy

0.44

0.02–10.05

0.61

 1-year recovery rate of ON palsy

5.39

0.26–11.96

0.277

Distant metastasis-free survival

 Sex

4.36

0.44–26.62

0.316

 Age

1.127

0.26–4.94

0.874

 N stage

6.654

1.08–41.06

0.041*

 Histological type

1.719

0.29–10.31

0.55

 Treatment

0.536

0.13–2.25

0.395

 Radiation dose

0.438

0.1–1.91

0.273

 Tumor volume

0.809

0.17–3.71

0.785

 Number of CN palsy symptom

1.39

0.24–7.63

0.735

 Initial TN palsy symptom

1.91

0.34–10.78

0.464

 Initial AN palsy symptom

1.552

0.13–18.68

0.729

 Initial ON palsy symptom

0.798

0.22–20.34

0.972

 1-year recovery rate of TN palsy

0.54

0.06–4.47

0.567

 1-year recovery rate of AN palsy

2.29

0.12–43.43

0.58

 1-year recovery rate of ON palsy

2.68

0.23–12.74

0.91

Locoregional recurrence-free survival

 Sex

0.807

0.07–9.74

0.866

 Age

1.792

0.22–14.6

0.586

 N stage

2.194

0.23–20.74

0.493

 Histological type

2.21

0.2–24.47

0.518

 Treatment

1.211

0.16–9.07

0.852

 Radiation dose

2.794

0.38–20.67

0.314

 Tumor volume

1.96

0.21–18.63

0.558

 Number of CN palsy symptom

4.143

0.53–32.21

0.174

 Initial TN palsy symptom

0.721

0.03–16.58

0.838

 Initial AN palsy symptom

1.476

0.12–3.61

0.811

 Initial ON palsy symptom

1.141

0.02–83.88

0.952

 1-year recovery rate of TN palsy

7.559

0.37–153.2

0.188

 1-year recovery rate of AN palsy

–

–

–

 1-year recovery rate of ON palsy

–

–

–