Table 2.

Multivariate Cox proportional hazards models of overall survival and head and neck squamous cell carcinoma specific survival.

Variables	OS		HNCSS
	HR (95% CI)	P-value	HR (95% CI)	P-value
Age
<65 years	Ref.		Ref.
≥65 years	0.803 (0.593–1.088)	0.157	0.728 (0.517–1.024)	0.068
Race
White	Ref.		Ref.
Black	0.855 (0.557–1.311)	0.472	0.927 (0.578–1.486)	0.753
Other	0.937 (0.445–1.972)	0.864	1.217 (0.571–2.597)	0.611
Gender
Male	Ref.		Ref.
Female	1.051 (0.710–1.555)	0.806	0.916 (0.576–1.458)	0.713
Primary Site
Oropharynx	Ref.		Ref.
Hypopharynx	1.156 (0.740–1.806)	0.524	1.116 (0.673–1.851)	0.671
Grade
Well differentiated	Ref.		Ref.
Moderately differentiated	0.724 (0.273–1.917)	0.515	0.562 (0.210–1.504)	0.251
Poorly/undifferentiated	0.598 (0.226–1.583)	0.301	0.441 (0.165–1.181)	0.103
Tumor stage
T1	Ref.		Ref.
T2	1.215 (0.687–2.150)	0.503	1.200 (0.341–2.273)	0.575
T3	1.486 (0.829–2.663)	0.184	1.365 (0.711–2.660)	0.349
T4	1.635 (0.920–2.809)	0.095	1.511 (0.811–2.815)	0.193
Nodal Stage
N0	Ref.		Ref.
N1	1.072 (0.558–2.060)	0.835	1.105 (0.500–2.438)	0.805
N2	1.241 (0.715–2.156)	0.443	1.526 (0.784–2.973)	0.214
N3	2.390 (1.259–4.536)	0.008	3.016 (1.422–6.397)	0.004
Treatment paradigm
C	Ref.		Ref.
C+R	0.909 (0.650–1.271)	0.577	0.920 (0.637–1.328)	0.655
C+S	1.861 (0.918–3.776)	0.085	1.392 (0.573–3.385)	0.465
C+R+S	0.710 (0.390–1.292)	0.262	0.698 (0.361–1.348)	0.284
Bone metastases
No	Ref.		Ref.
Yes	2.199 (1.563–3.093)	0.000	2.482 (1.719–3.584)	0.000
Brain metastases
No	Ref.		Ref.
Yes	0.794 (0.303–2.080)	0.639	0.857 (0.322–2.279)	0.757
Liver metastases
No	Ref.		Ref.
Yes	1.241 (0.798–1.930)	0.339	1.380 (0.961–2.213)	0.181
Lung metastases
No	Ref.		Ref.
Yes	1.533 (1.115–2.108)	0.008	1.702 (1.201–2.401)	0.003
HPV status
Negative	Ref.		Ref.
Positive	0.560 (0.401–0.782)	0.001	0.600 (0.415–0.867)	0.007

C, Chemotherapy; CI, confidence interval; HNCSS, head and neck cancers specific survival; HR, hazard ratio; HPV, human papillomavirus; Ref., reference; OS, overall survival; R, Radiotherapy; S, Surgery.