Table 5. Univariate and multivariate analyses of clinical predictors of lymphatic permeation.

Variables	Univariate analysis				Multivariate analysis
	HR	95% CI	P value		HR	95% CI	P value
Age (years)
<67	1				Not included in the multivariate model
>67	1.244	0.813–1.904	0.314
Sex
Female	1				1
Male	1.636	1.053–2.543	0.029*		1.276	0.668–2.439	0.46
Smoking history
Never-smoker	1				1
Ever-smoker	1.946	1.265–2.995	0.002*		1.762	0.953–3.258	0.071
CEA
Within the normal range	1				1
Elevated	2.337	1.461–3.738	<0.001*		1.935	1.152–3.251	0.013*
FEV1%
>70	1				1
<70	1.988	1.264–3.125	0.003*		1.661	0.995–2.770	0.052
Unknown
Tumor size on chest CT (cm)
<2.0	1				1
>2.0	2.413	1.545–3.770	<0.001*		2.603	1.601–4.231	<0.001*
Tumor laterality
Right	1				Not included in the multivariate model
Left	0.936	0.778–1.996	0.764
Primary lobe
Upper or middle lobe	1				Not included in the multivariate model
Lower lobe	1.245	0.626–3.256	0.361
Histological type
Adenocarcinoma	1				1
Non-adenocarcinoma	1.995	1.132–3.514	0.017*		1.626	0.820–3.225	0.164

Numbers in parentheses indicate percentages. *, significance level. HR, hazard ratio; CI, confidence interval; CEA, preoperative serum carcinoembryonic antigen level, normal upper limit at 5 ng/mL; FEV₁%, forced expiratory volume percent in 1 s; CT, computed tomography.