Table 1. Clinical characteristics and surgical outcomes.

Variables	Number of patients	%
Age, years
≤65	5,847	48.0
>65	6,323	52.0
Gender
Male	6,454	53.0
Female	5,716	47.0
Race
Whites	10,197	83.8
Blacks	1,084	8.9
Others	889	7.3
Laterality
Left	5,765	47.4
Right	6,405	52.6
Histology
Adenocarcinoma	7,181	59.0
Squamous cell carcinoma	3,757	30.9
Others	1,232	10.1
Pathological stage
IIA	1,822	15.0
IIB	3,970	32.6
IIIA	4,956	40.7
IIIB	1,422	11.7
Pathological T stage
T1	3,164	26.0
T2	6,770	55.6
T3	814	6.7
T4	1,422	11.7
Pathological N stage
N1	7,045	57.9
N2	5,125	42.1
Type of surgery
Lobectomy or bilobectomy	10,240	84.1
Pneumonectomy	1,930	15.9