Table 2. Univariate and multivariate analyses of overall survival (OS).

Characteristics	Median OS(month)	Univariate analysis		Multivariate analysis
		Log-rank	P	HR(95%CI)	P
Marital status		544.62	<.0001
Married	14			Ref.
Divorced/separated	11			1.15(1.12, 1.18)	<.0001
Widowed	10			1.16(1.14, 1.19)	<.0001
Never married	11			1.15(1.12, 1.18)	<.0001
Gender		530.73	<.0001
Male	11			Ref.
Female	14			0.81(0.80, 0.83)	<.0001
Age		1486.10	<.0001
<60	14			Ref.
60-69	14			1.13(1.11, 1.16)	<.0001
70-79	12			1.34(1.30, 1.37)	<.0001
≥80	8			1.65(1.61, 1.70)	<.0001
Race		131.47	<.0001
White	12			Ref.
Black	10			1.01(0.98, 1.03)	0.5546
Others	14			0.87(0.84, 0.89)	<.0001
Diagnosis year		53.38	<.0001
2004-2008	12			Ref.
2009-2012	13			0.93(0.91, 0.95)	<.0001
Median household income		116.53	<.0001
Quartile 4	13			Ref.
Quartile 3	13			0.99(0.97, 1.02)	0.6257
Quartile 2	12			1.05(1.03, 1.08)	<.0001
Quartile 1	11			1.05(1.02, 1.07)	0.0003
Grade		8018.64	<.0001
I	64			Ref.
II	32			1.35(1.28, 1.42)	<.0001
III	13			1.55(1.47, 1.63)	<.0001
IV	10			1.66(1.54, 1.79)	<.0001
Unknown	8			1.49(1.42, 1.57)	<.0001
TNM stage		21640.45	<.0001
I	63			Ref.
II	30			1.60(1.53, 1.67)	<.0001
III	13			1.85(1.79, 1.90)	<.0001
IV	6			3.23(3.13, 3.33)	<.0001
Histology		2490.73	<.0001
adenocarcinoma	16			Ref.
squamous carcinoma	13			1.14(1.11, 1.16)	<.0001
Others	8			1.15(1.13, 1.18)	<.0001
Surgery		19418.35	<.0001
Yes	71			Ref.
No	8			2.67(2.59, 2.76)	<.0001
Radiotherapy		1563.04	<.0001
Yes	10			Ref.
No	15			1.14(1.12, 1.16)	<.0001