Table II.

Influence of different variables on cancer specific survival for patients with ES-SCLC analyzed by Cox proportional hazard model.

	Univariate analysis		Multivariate analysis
Variable	χ2	P-value	HR	95% CI	P-value
Age, years	152.30	<0.001			<0.001
≤49			Reference
50–64			1.093	0.966–1.236	0.158
≥65			1.378	1.220–1.555	<0.001
Ethnicity	12.70	0.002			0.006
White			Reference
Black			0.954	0.877–1.038	0.274
Others			0.814	0.714–0.928	0.002
Sex	27.70	<0.001			<0.001
Male			Reference
Female			0.890	0.849–0.934	<0.001
AJCC T stage	27.96	<0.001			0.008
T1			Reference
T2			1.142	1.037–1.258	0.007
T3			1.147	1.040–1.266	0.006
T4			1.150	1.050–1.260	0.003
AJCC N stage	27.12	<0.001			0.003
N0			Reference
N1			0.953	0.848–1.071	0.417
N2			1.059	0.981–1.144	0.143
N3			0.973	0.891–1.062	0.533
Metastatic lesions	78.73	<0.001			<0.001
1			Reference
>1			1.237	1.178–1.299	<0.001
Radiotherapy	452.61	<0.001			<0.001
Yes			Reference
No			1.591	1.513–1.672	<0.001

ES-SCLC, extensive stage small cell lung cancer; HR, hazard ratio, CI, confidence interval; AJCC, American Joint Committee on Cancer; T, Tumor; N, Node.