Table 5.

Cox model for overall survival.

Variable	Categories	Hazard ratio (95% CI)	p-value	DF
Histology	Neuroendocrine	Reference	0.002	5
	Mucoepidermoid	1.15 (0.49–2.68)	0.747	1
	Squamous	6.26 (1.66–23.58)	0.007	1
	Adenocarcinoma	1.35 (0.51–3.57)	0.549	1
	Blastoma	3.47 (1.80–6.69)	<0.001	1
	Sarcoma	1.22 (0.49–3.07)	0.673	1
Stage	Local/Regional	Reference	0.040	2
	Distant	0.47 (0.18–1.22)	0.122	1
	Unknown	0.42 (0.02–0.91)	0.028	1
Surgery	Yes	Reference	–	–
	No	6.29 (2.92–13.54)	<0.001	1

^‡CI, confidence interval; DF, degrees of freedom.