Table 2.

Cox regression analysis of overall survival: HR (hazard ratio); CI, confidence interval; LRP, low-risk pattern; HRP, high-risk pattern. Univariable Cox regression analyses were performed separately for each variable. The multivariable Cox regression model included pT stage, tumor grade, nodal status, distant metastases, architectural growth pattern, and the proportion of p16-positive vessels. The multivariable model included 199 cases and 76 events. Endothelial p16 staining intensity was not included in the multivariable model because the proportion of p16-positive vessels was selected as the primary vascular p16 variable

Variable	Comparison	Univariable Cox analysis n/events	Univariable HR (95% CI)	p value	Multivariable HR (95% CI)	p value
pT stage	pT3/4 vs. pT1/2	248/90	2.672 (1.758–4.063)	< 0.001	2.338 (1.425–3.835)	< 0.001
Tumor grade	G3/G4 vs. G1/G2	248/90	3.203 (2.016–5.089)	< 0.001	1.065 (0.560–2.026)	0.848
Nodal status	pN1 vs. pN0/cN0	244/90	3.541 (1.789–7.008)	< 0.001	1.109 (0.426–2.883)	0.833
Distant metastases	M1 vs. M0	244/90	3.471 (2.104–5.727)	< 0.001	2.919 (1.517–5.616)	0.001
Architectural growth pattern	HRP vs. LRP	215/79	2.496 (1.597–3.899)	< 0.001	2.070 (1.203–3.561)	0.009
p16-positive vessels	≥ 35% vs. < 35%	222/84	0.462 (0.296–0.722)	< 0.001	0.687 (0.404–1.169)	0.167
Endothelial p16 staining intensity	Score 1 vs. 0	222/84	1.036 (0.560–1.916)	0.910	—	—
Endothelial p16 staining intensity	Score 2 vs. 0	222/84	0.415 (0.211–0.815)	0.011	—	—