Table 3. Multivariate analysis of LRC, DFS and OS.

	LRC			DFS			OS
	HR	95% CI	P	HR	95% CI	P	HR	95% CI	P
p16INK4a
Cytoplasmic	0.68	0.35-1.28	NS	0.75	0.47-1.21	NS	1.00	0.61-1.65	NS
Nuclear	0.25	0.09-0.66	0.005	0.50	0.29-0.89	0.01	0.62	0.35-1.12	NS
Negative	1 (ref)			1 (ref)			1 (ref)
Gender
Male	0.58	0.28-1.19	NS	0.85	0.48-1.51	NS	1.66	0.85-3.22	NS
Female	1 (ref)			1 (ref)			1 (ref)
Age
continuous	1.02	0.98-1.05	NS	1.03	1.01-1.06	0.01	1.02	0.99-1.04	NS
Nodal stage*
N0-N1	0.70	0.34-1.45	NS	0.99	0.60-1.62	NS	0.77	0.46-1.27	NS
N2-N3	1 (ref)			1 (ref)			1 (ref)
T stage*
T1-2	0.52	0.25-1.05	NS	0.47	0.28-0.80	0.004	0.35	0.20-0.61	0.0001
T3-4	1 (ref)			1 (ref)			1 (ref)
Tumor site
Soft palate	0.19	0.02-1.89	NS	0.33	0.06-1.62	NS	0.75	0.15-3.79	NS
Tonsil	0.69	0.30-1.60	NS	0.80	0.43-1.50	NS	1.12	0.60-2.10	NS
BOT/vallecula	0.59	0.24-1.46	NS	0.98	0.52-1.86	NS	1.00	0.52-1.92	NS
Pharyngeal wall	1 (ref)			1 (ref)			1 (ref)
Smoking history
Former	0.49	0.11-2.17	NS	0.82	0.32-2.15	NS	0.67	0.26-1.75	NS
Current	0.67	0.36-1.28	NS	1.57	0.71-3.47	NS	1.17	0.54-2.56	NS
Never	1 (ref)			1 (ref)			1 (ref)

Abbreviations: NS, not significant; BOT, base of tongue; HR, hazard ratio; CI, confidence interval; ref, reference; LRC, locoregional control; DFS, disease free survival; OS, Overall survival;

^*International Union of Cancer Research 1982 classification.

P was determined by cox-regression analysis