Table 3. Multivariate analyses of clinical features on PFS and OS.

Variable	PFS			OS
	HR	95% CI	P	HR	95% CI	P
Age: < 65 vs. ≥ 65	0.704	0.561–1.319	0.473	0.961	0.695–1.172	0.395
Sex: male vs. female	1.217	0.877–1.954	0.861	1.096	0.827–2.311	0.482
Distant metastases: Yes vs. No	1.466	1.071–2.554	0.021	1.915	1.096–2.751	0.038
Smoking: never vs. current/former	0.727	0.486–1.579	0.162	0.841	0.614–1.897	0.531
CTC count: positive vs. negative	0.875	0.639–1.572	0.243	0.807	0.624–1.995	0.427
CTC count: relative low level vs. high level	0.656	0.473–1.000	0.049	0.715	0.551–1.821	0.139

Abbreviations: CTC, circulating tumor cell; HR, hazard ratio; CI, confidence interval.