Table 2. Multivariate analysis of overall survival and lung cancer-specific survival in M1a NSCLC patients only due to ipsilateral malignant pleural effusion.

Variables	Overall survival		Lung cancer-specific survival
	Hazard Ratios (95% CI)	p Value	Hazard Ratios (95% CI)	p Value
Age
≤65 y	1.00 (Reference)		1.00 (Reference)
>65 y	1.412 (1.259-1.585)	<0.001	1.368 (1.214-1.543)	<0.001
Gender
Female	1.00 (Reference)		1.00 (Reference)
Male	1.118 (1.008-1.241)	0.035	1.086 (0.974-1.212)	0.138
Married
Yes	1.00 (Reference)		1.00 (Reference)
No	1.322 (1.192-1.466)	<0.001	1.279 (1.147-1.426)	<0.001
Race
White	1.00 (Reference)		1.00 (Reference)
Black	0.968 (0.831-1.127)	0.672	0.965 (0.822-1.134)	0.668
Other	0.628 (0.517-0.762)	<0.001	0.612 (0.499-0.752)	<0.001
Tumor Size
≤3cm	1.00 (Reference)		1.00 (Reference)
≤5cm	0.989 (0.862-1.135)	0.880	0.999 (0.865-1.155)	0.994
≤7cm	1.144 (0.986-1.327)	0.075	1.152 (0.985-1.347)	0.077
>7cm	1.339 (1.150-1.560)	<0.001	1.348 (1.148-1.583)	<0.001
Location
Main bronchus	1.00 (Reference)		1.00 (Reference)
Upper	1.021 (0.841-1.241)	0.831	1.041 (0.848-1.279)	0.700
Middle	0.949 (0.717-1.256)	0.713	0.933 (0.693-1.257)	0.649
Lower	0.911 (0.744-1.115)	0.367	0.917 (0.741-1.135)	0.428
Overlap	1.462 (1.012-2.115)	0.043	1.416 (0.955-2.099)	0.084
Lymph node status
N0	1.00 (Reference)		1.00 (Reference)
N1	0.880 (0.715-1.082)	0.225	0.871 (0.697-1.088)	0.223
N2	1.156 (1.027-1.301)	0.016	1.216 (1.073-1.379)	0.002
N3	1.076 (0.898-1.291)	0.427	1.130 (0.934-1.367)	0.210
NX	1.134 (0.881-1.459)	0.328	1.226 (0.944-1.591)	0.126
Histology
Adenocarcinoma	1.00 (Reference)		1.00 (Reference)
Squamous cell carcinoma	1.258 (1.094-1.447)	0.001	1.255 (1.084-1.453)	0.002
Other	1.360 (1.206-1.533)	<0.001	1.317 (1.160-1.495)	<0.001
Primary tumor resection
Yes	1.00 (Reference)		1.00 (Reference)
No	2.136 (1.645-2.772)	<0.001	2.053 (1.568-2.690)	<0.001
Radiotherapy
Yes	1.00 (Reference)		1.00 (Reference)
No	1.639 (1.447-1.856)	<0.001	1.612 (1.415-1.836)	<0.001

Bold values corresponds to the comparisons with P < 0.001.