Table 2. Cox proportional regression model for OS and RFS.

Variables	OS						RFS
	Univariate			Multivariate			Univariate			Multivariate
	HR	95% CI	P	HR	95% CI	P	HR	95% CI	P	HR	95% CI	P
Sex
Male	Reference	0.247-0.919	0.027	Reference	0.331-1.296	0.224	Reference	0.435-1.216	0.224
Female	0.477			0.655			0.727
Age (yr)
< 65	Reference	1.090-2.545	0.018	Reference	1.322-3.143	0.001	Reference	0.909-1.905	0.146
≥ 65	1.666			2.038			1.316
Smoking
Never smoker	Reference	0.624-1.465	0.956				Reference	0.657-1.409	0.842
Current or former smoker	0.835						0.962
Histology
SqCC	Reference	0.400-0.969	0.036	Reference	0.571-1.456	0.698	Reference	0.505-1.087	0.126
Non-SqCC	0.623			0.911			0.741
ECOG PS
0	Reference	0.932-2.146	0.104				Reference	1.041-2.187	0.030	Reference	0.985-2.113	0.060
1	1.414						1.509			1.443
Surgery
Lobectomy and others	Reference	0.660-1.993	0.626				Reference	0.849-2.182	0.201
Pneumonectomy	1.147						1.361
TNM stage
pI	Reference			Reference			Reference			Reference
pII	1.439	0.922-2.246	0.109	1.400	0.887-2.210	0.149	1.636	1.096-2.442	0.016	1.628	1.086-2.438	0.018
pIII	2.260	1.318-3.876	0.003	2.222	1.248-3.954	0.007	2.950	1.812-4.804	< 0.001	2.350	1.394-3.962	0.001
PLT-PLR
0	Reference			Reference			Reference			Reference
1	1.360	0.882-2.099	0.148	1.356	0.886-2.075	0.161	1.204	0.818-1.774	0.310	1.248	0.853-1.828	0.254
2	3.787	1.986-7.220	< 0.001	3.473	1.765-6.835	< 0.001	3.087	1.712-5.565	< 0.001	2.286	1.243-4.206	0.008

Abbreviation: OS, overall survival; RFS, relapse-free survival; HR, hazard ratio; 95% CI, 95% confidence interval; SqCC, squamous cell carcinoma; Non-SqCC, non-squamous cell carcinoma; ECOG PS, Eastern Cooperative Oncology Group Performance Status; PLT, platelet; PLR, platelet-to-lymphocyte ratio