Table 3 Univariate and multivariate Cox regression analysis for overall survival in the with PET/CT NPC cohort

Age (years)

0.034

0.040

 < 45

1 (reference)

1 (reference)

 ≥ 45

2.277 (1.064–4.873)

2.293 (1.037–5.074)

Sex

0.964

 Male

1 (reference)

 Female

0.978 (0.373–2.562)

rEBV DNA (copies/ml)

0.691

 Undetectable

1 (reference)

 Detectable

1.165 (0.548–2.475)

rLactate dehydrogenase (U/L)

0.620

 < 240

1 (reference)

 ≥ 240

0.603 (0.082–4.446)

rC-reactive protein (mg/L)

< 0.001

0.003

 < 10.5

1 (reference)

1 (reference)

 ≥ 10.5

4.465 (2.064–9.660)

3.552 (1.560–8.087)

rNLR

0.344

 < 3.7

1 (reference)

 ≥ 3.7

1.445 (0.675–3.095)

rT category^#

0.062

 rT0-2

1 (reference)

 rT3-4

2.122 (0.962–4.683)

rN category^#

0.372

 rN0

1 (reference)

 rN1-3

0.716 (0.344–1.49)

rStage^#

0.133

 r0-rII

1 (reference)

 rIII-rIVA

1.745 (0.843–3.608)

rT category*

0.010

 rT0-2

1 (reference)

 rT3-4

2.684 (1.263–5.703)

rN category*

0.701

 rN0

1 (reference)

 rN1-3

0.868 (0.423–1.784)

rStage*

0.023

0.036

 r0-rII

1 (reference)

1 (reference)

 rIII-rIVA

2.600 (1.143–5.916)

2.662 (1.066–6.649)

Treatment

0.019

0.316

 Palliative treatment

1 (reference)

1 (reference)

 Re-radiotherapy + Salvage Surgery

0.379 (0.168–0.853)

0.653 (0.284–1.502)

PET/CT SUVmax

0.015

0.179

 < 11.9

1 (reference)

1 (reference)

 ≥ 11.9

2.464 (1.195–5.078)

1.730 (0.777–3.852)