Table 4.

Univariate and Cox model analyses of the disease-specific survival in the 674 patients.

Variables	Univariate	Cox model
	p	p	HR[95% CI]
Age (<40 vs. ≥40)	0.231
Sex (Male vs. female)	0.156
Smoker	<0.001	<0.001	1.336 [1.075–1.748]
Drinker	0.374
Primary site
Tongue + The mouth floor vs. others	<0.001	<0.001	2.132 [1.426–3.164]
Pathologic tumor stage
T3+T4 vs. T1+T2	<0.001	<0.001	3.128 [1.476–5.129]
Tumor differentiation
Moderate + poor vs. well	<0.001	<0.001	2.006 [1.387–3.814]
Perineural invasion	<0.001	<0.001	2.061 [1.337–3.994]
Lymphovascular invasion	<0.001	<0.001	2.116 [1.452–3.860]
Neck lymph node stage	<0.001
N0
N1		<0.001	1.456 [1.027–1.999]
N2		<0.001	2.375 [1.564–3.555]
N3		<0.001	3.467 [2.622–5.932]
Number of lymph node examined
<22 vs. ≥22	0.513
HPV positivity	0.673
p16 positivity	0.024	<0.001	1.321 [1.048–1.733]
Positive margin	<0.001	<0.001	3.776 [1.671–5.997]
Number of positive lymph nodes	<0.001
0
1-2		<0.001	1.862 [1.122–2.442]
3-4		<0.001	3.189 [2.611–4.554]
≥5		<0.001	6.316 [4.673–10.227]