Table 2.

Univariate Cox analysis of predictors for locoregional control (LRC) and overall survival (OS)

Variable	LRC		OS
	P	HR [95%CI]	P	HR [95%CI]
Age
≤50		ref		ref
>50	0.547	2.16 [0.73–5.90]	0.356	2.00 [0.62–4.65]
Sex
Male
Female	0.222	1.23 [0.47–7.12]	0.317	1.87 [0.41–8.10]
Primary site
Major		ref		ref
Minor	0.425	2.37 [0.83–7.73]	0.321	2.64 [0.77–8.11]
Tumor stage
T1 + T2		ref		ref
T3 + T4	0.005	3.10 [1.22–9.05]	0.007	2.90 [1.17–7.36]
Perineural invasion
No		ref		ref
Yes	0.126	2.45 [0.63–10.08]	0.243	2.76 [0.86–9.99]
Lymphovascular invasion
No		ref		ref
Yes	0.014	2.72 [1.35–8.17]	0.015	3.00 [1.74–9.45]
Histologic grade
Low		ref		ref
Intermediate	0.178	1.98 [0.32–11.67]	0.435	2.27 [0.46–17.22]
High	< 0.001	3.86 [1.88–17.13]	< 0.001	4.07 [1.65–20.67]
Neck stage
N1		ref		ref
N2/3	0.017	2.17 [1.65–6.43]	0.026	2.33 [1.70–7.57]
Level IV/V involvement
No		ref		ref
Yes	0.156	2.28 [0.65–8.10]	0.474	3.08 [0.46–7.76]
Extranodal extension
No		ref		ref
Yes	0.532	1.89 [0.66–14.27]	0.482	2.00 [0.59–16.10]
Margin
Negative		ref		ref
Positive	< 0.001	4.27 [2.21–20.99]	< 0.001	5.03 [1.86–44.62]
Number of metastatic LNs*
≤4		ref		ref
>4	< 0.001	3.19 [1.64–15.23]	< 0.001	3.48 [1.95–18.25]
Adjuvant therapy
Radiotherapy		ref		ref
Chemoradiotherapy	0.485	1.14 [0.36–4.22]	0.367	0.99 [0.17–3.87]

* LN: lymph node