Table 5

Univariate and multivariable analysis of poor prognostic factors and risk factors for recurrence in patients with stage I non-small cell lung cancer

Variables		Univariate analysis			Multivariate analysis
Variables		HR	95% CI	P-value	HR	95% CI	P-value
Age (years)	<65	1		0.001^*	1		0.047^*
Age (years)	>65	1.511	1.176 to 1.942	0.001^*	1.295	1.003 to 1.672	0.047^*

Gender	Women	1		0.001^*
Gender	Men	1.547	1.191 to 2.008	0.001^*	Not included in multivariable model

Smoking habits	Non-smoker	1		<0.001^*
Smoking habits	Ever smoker	1.799	1.368 to 2.366	<0.001^*	Not included in multivariable model

FEV₁/FVC (%)	>70	1		0.001^*
FEV₁/FVC (%)	<70	1.605	1.223 to 2.108	0.001^*	Not included in multivariable model

CEA	Within normal range	1		0.001^*
CEA	Elevated	1.527	1.186 to 1.967	0.001^*	Not included in multivariable model

Tumor size (cm)	<3.0	1		<0.001^*	1		0.023^*
Tumor size (cm)	>3.0	2.384	1.861 to 3.054	<0.001^*	1.366	1.044 to 1.786	0.023^*

Histological type	Adenocarcinoma	1		0.001^*
Histological type	Non-adenocarcinoma	1.732	1.336 to 2.243	0.001^*	Not included in multivariable model

Histological differentiation	Well differentiated	1		<0.001^*	1		0.001^*
Histological differentiation	Moderately/poorly differentiated	3.454	2.517 to 4.440	<0.001^*	1.831	1.299 to 2.582	0.001^*

Lymphatic permeation	Absent	1		<0.001^*	1		0.031^*
Lymphatic permeation	Present	2.175	1.672 to 2.830	<0.001^*	1.351	1.027 to 1.777	0.031^*

Intratumoral vascular invasion	Absent	1		<0.001^*	1		<0.001^*
Intratumoral vascular invasion	Present	4.242	3.274 to 5.496	<0.001^*	2.487	1.838 to 3.366	<0.001^*

Visceral pleural invasion	Absent	1		<0.001^*	1		0.001^*
Visceral pleural invasion	Present	2.953	2.291 to 3.807	<0.001^*	1.594	1.210 to 2.099	0.001^*

↵* Indicates significance.
CEA, preoperative serum carcinoembryonic antigen level (normal upper limit 5 ng/ml); FEV₁/FVC, forced expiratory volume in 1 s to forced vital capacity ratio; HR, HR for recurrence.