Table 3 Multivariable analysis of prognostic factors for nasopharyngeal carcinoma patients (combination of AKR1C4 and EBV DNA included)

LRFS

AKR1C4 + EBV DNA

Intermediate risk vs. low

5.182 (1.451–18.505)

0.011

High risk vs. low

7.596 (1.736–33.248)

0.007

T stage (4 vs. 1/2/3)

6.102 (0.740–50.285)

0.093

N stage (2/3 vs. 0/1)

1.245 (0.498–3.114)

0.640

Disease stage (IVa vs. I/II/III)

0.377 (0.046–3.097)

0.364

BMI (≥ 18.5 vs. < 18.5 kg/m²)

0.465 (0.099–2.181)

0.331

Smoking history (yes vs. no)

1.752 (0.746–4.114)

0.198

OS

AKR1C4 + EBV DNA

Intermediate risk vs. low

2.345 (0.985–5.581)

0.054

High risk vs. low

3.567 (1.380–9.224)

0.009

T stage (4 vs. 1/2/3)

3.425 (1.121–10.471)

0.031

N stage (2/3 vs. 0/1)

3.863 (1.717–8.693)

0.001

Disease stage (IVa vs. I/II/III)

0.781 (0.248–2.461)

0.673

BMI (≥ 18.5 vs. < 18.5 kg/m²)

0.378 (0.146–0.979)

0.045

Smoking history (yes vs. no)

1.577 (0.806–3.806)

0.183

PFS

AKR1C4 + EBV DNA

Intermediate risk vs. low

2.310 (1.172–4.552)

0.016

High risk vs. low

3.601 (1.688–7.684)

0.001

T stage (4 vs. 1/2/3)

2.588 (1.091–4.603)

0.031

N stage (2/3 vs. 0/1)

2.520 (1.379–4.603)

0.003

Disease stage (IVa vs. I/II/III)

0.976 (0.407–2.340)

0.956

BMI (≥ 18.5 vs. < 18.5 kg/m²)

0.518 (0.223–1.201)

0.125

Smoking history (yes vs. no)

1.679 (0.996–2.830)

0.052

DMFS

AKR1C4 + EBV DNA

Intermediate risk vs. low

1.835 (0.820–4.106)

0.140

High risk vs. low

2.993 (1.248–7.176)

0.014

T stage (4 vs. 1/2/3)

1.851 (0.752–4.559)

0.181

N stage (2/3 vs. 0/1)

4.009 (1.798–8.937)

0.001

Disease stage (IVa vs. I/II/III)

1.456 (0.569–3.727)

0.433

BMI (≥ 18.5 vs. < 18.5 kg/m²)

0.383 (0.159–0.919)

0.032

Smoking history (yes vs. no)

1.655 (0.886–3.091)

0.114