Table II.

Univariate and multivariate Cox model of prognostic factors for overall survival (OS).

	Univariate		Multivariate
Variables	HR (95% CI)	P-value	HR (95% CI)	P-value
Age (continuous)	1.02 (0.98-1.06)	0.291
Sex (male vs. female)	3.14 (1.27-7.76)	0.013	3.12 (1.24-7.81)	0.014
Smoking (former/current vs. never)	2.04 (0.89-4.64)	0.089
Cell differentiation (well vs. others)	1.56 (0.69-3.49)	0.279
Tumor size (>2 cm vs. ≤2 cm)	3.70 (1.49-9.16)	0.005
Lympho-vascular invasion (no vs. yes)	0.44 (0.26-1.79)	0.449
Vascular invasion (no vs. yes)	0.85 (0.28-2.54)	0.782
Pleural invasion (no vs. yes)	0.88 (0.26-2.95)	0.845
Pathologic stage (IB vs. IA)	3.09 (1.46-6.51)	0.003	2.28 (1.03-5.03)	0.041
CD155 expression (positive vs. negative)	3.74 (1.71-8.15)	<0.001
PD-L1 (positive vs. negative)	3.04 (1.25-7.34)	0.014
CD155 expression and PD-L1 expression (CD155+/PD-L1+ vs. others)	5.26 (2.19-12.61)	<0.001	3.86 (1.51-9.89)	0.004
Mode of lung resection (sub-lobar resection vs. lobectomy)	0.58 (0.13-2.54)	0.477
Adjuvant chemotherapy (not performed vs. performed)	1.28 (0.38-4.27)	0.682

95% CI, 95% confidence interval; CD155⁺, CD155 expression-positive; HR, hazard ratio; PD-L1, programmed death-ligand 1; PD-L1⁺, PD-L1 expression-positive.