Table 3. Results of univariate and multivariate survival analyses for overall survival by the Cox proportional hazard model (n = 90).

Variable	Categories	RR (95%CI)	P-value
Univariate survival analysis
Age (years)	<65/>65	0.392 (0.143–1.080)	0.070
Type	Glottic/Supraglottic	1.939 (0.803–4.681)	0.141
Thyroid-cartilage invasion	No/Yes	4.942 (2.030–12.032)	<0.001
T-Stage	T1 and T2/T3 and T4	3.584 (1.301–9.873)	0.014
Lymphatic metastasis	No/Yes	6.176 (2.453–15.545)	<0.001
Clinical stage	I and II/III and IV	5.925 (1.735–20.231)	0.005
Pathological differentiation	Moderately and highly/Poorly differentiated	5.545 (2.269–13.548)	<0.001
STC1 expression	Negative/Low/High	1.048 (0.536–2.050)	0.890
STC2 expression	Negative/Low/High	3.559 (1.694–7.479)	0.001
Multivariate survival analysis
Lymphatic metastasis	No/Yes	3.064 (1.096–8.566)	0.033
Pathological differentiation	Moderately and highly/Poorly differentiated	3.176 (1.219–8.269)	0.018
STC2 expression	Negative/Low/High	2.477 (1.119–5.485)	0.025