Table 4.

Univariate and multivariate Cox proportional hazards analysis of CSS for patients with metastatic non-small cell lung cancer in the SEER database

Variables	Univariate analysis	P value	Multivariate analysis	P value
	HR (95%CI)		HR (95%CI)
Gender		<0.001		<0.001
Male	1.000		1.000
Female	0.802 (0.784-0.820)		0.826 (0.807-0.845)
Age		<0.001		<0.001
≤60	1.000		1.000
>60	1.264(1.233-1.296)		1.144(1.115-1.173)
Race		<0.001		<0.001
Caucasian	1.000		1.000
Black	0.996(0.963-1.029)	0.791	0.983(0.951-1.017)	0.319
Others	0.689(0.661-0.717)	<0.001	0.686(0.658-0.715)	<0.001
Grade		<0.001		<0.001
I	1.000		1.000
II	2.507(1.025-6.132)	0.044	1.238(1.140-1.345)	<0.001
III	2.297(1.145-4.609)	0.019	1.577(1.457-1.707)	<0.001
IV	2.368 (1.182-4.744)	0.015	1.827 (1.604-2.081)	<0.001
Unknown	2.433 (1.217-4.867)	0.012	1.549 (1.434-1.674)	<0.001
T stage		<0.001		<0.001
T1	1.000		1.000
T2	1.127 (1.057-1.202)	<0.001	1.129 (1.092-1.167)	<0.001
T3	1.095 (1.022-1.172)	0.010	1.293 (1.246-1.342)	<0.001
T4	1.127(1.057-1.203)	<0.001	1.485(1.428-1.544)	<0.001
Tx	1.316(1.243-1.394)	<0.001	1.441(1.394-1.490)	<0.001
Surgery of Metastases		<0.001		<0.001
No	1.000		1.000
Yes	0.727(0.655-0.907)	<0.001	0.757(0.724-0.792)	<0.001
Unknown	1.271(0.912-1.771)	0.157	0.811(0.622-1.056)	0.120
Radiotherapy		<0.001		<0.001
Yes	1.000		1.000
No	2.884(2.496-3.333)	<0.001	1.133 (1.036-1.240)	0.006
Unknown	1.672(1.606-1.742)	<0.001	1.095(1.068-1.122)	<0.001
Chemotherapy		<0.001		<0.001
No	1.000		1.000
Yes	0.382(0.373-0.391)		0.377(0.368-0.386)
Metastasis site		<0.001		<0.001
Brain	1.000		1.000
Bone	0.900(0.867-0.934)	<0.001	0.959(0.922-0.996)	0.032
Liver	1.210(1.151-1.272)	<0.001	1.087(1.033-1.143)	0.001
Lung	0.771(0.744-0.798)	<0.001	0.697 (0.672-0.722)	<0.001
multisite	1.207(1.172-1.243)	<0.001	1.282(1.244-1.321)	<0.001