Table 2 Univariable Cox-regressions of tumor volume (GTV-T) for local failure, progression free survival and overall survival for all patients or separately within each T-classification or by p16-stratification. HR: Hazard Ratio, lr-test: the difference in -2 log likelihood between the null model and the full model

Without p16-stratification (all pat)

GTVT-volume (per cm³)

1.024–1.037

 < 0.001

64

1.020–1.029

 < 0.001

76

1.020–1.030

GTVT-volume within T1 (per cm³)

1.001–1.338

0.04

3.6

1.018–1.150

0.01

5.2

1.034–1.179

GTVT-volume within T2 (per cm³)

1.013–1.069

0.003

5.8

1.012–1.045

 < 0.001

9.1

1.002–1.040

GTVT-volume within T3 (per cm³)

1.007–1.042

0.005

5.9

1.010–1.035

 < 0.001

10

1.008–1.032

GTVT-volume within T4 (per cm³)

1.009–1.028

 < 0.001

12

1.007–1.023

 < 0.001

12

1.003–1.021

With p16-stratification

p16 + : GTVT-volume (per cm³)

1.027–1.049

 < 0.001

34

1.020–1.036

 < 0.001

36

1.015–1.033

p16-: GTVT-volume (per cm³)

1.010–1.028

 < 0.001

13

1.006–1.022

 < 0.001

9.2

1.010–1.027