Table 1.

Distribution of clinicopathologic characteristics of the patients in the four categories, as classified by the number of examined LNs

Variable	No. of examined nodes (n)				P-value
	1–2	3–7	8–11	≥12
Gender					0.744
Male	21 (3.8%)	81 (14.8%)	80 (14.6%)	210 (38.3%)
Female	7 (1.35%)	28 (5.1%)	30 (5.5%)	92 (16.8%)
Age (years)					0.022
≤65	13 (2.4%)	74 (13.5%)	84 (15.3%)	203 (37.0%)
>65	15 (2.7%)	35 (6.4%)	26 (4.7%)	99 (18.0%)
Smoking status					0.956
Never	11 (2.0%)	46 (8.4%)	43 (7.8%)	126 (23.0%)
Former	17 (3.1%)	63 (11.5%)	67 (12.2%)	176 (32.1%)
Tumor size (cm)					0.984
≤4	21 (3.8%)	84 (15.3%)	86 (15.7%)	235 (42.8%)
>4	7 (1.3%)	25 (4.6%)	24 (4.4%)	67 (12.2%)
Tumor location					0.002
Left	12 (2.2%)	48 (8.7%)	62 (11.3%)	106 (19.3%)
Right	16 (2.9%)	61 (11.1%)	48 (8.7%)	196 (35.7%)
Histological type					0.300
Squamous	6 (1.1%)	30 (5.5%)	31 (5.6%)	107 (19.5%)
Adenocarcinoma	19 (3.5%)	73 (13.3%)	66 (12.0%)	166 (30.2%)
Adenosquamous	2 (0.4%)	5 (0.9%)	11 (2.0%)	20 (3.6%)
Others	1 (0.2%)	1 (0.2%)	2 (0.4%)	8 (1.5%)
Visceral pleura invasion					0.108
Yes	11 (2.0%)	67 (12.2%)	71 (12.9%)	184 (33.5%)
No	17 (3.1%)	42 (7.7%)	39 (7.1%)	118 (21.5%)
Bronchia invasion					0.002
Yes	3 (0.5%)	20 (3.6%)	22 (4.0%)	97 (17.7%)
No	25 (4.6%)	89 (16.2%)	88 (16.0%)	205 (37.3%)
Surgical approach					<0.001
Thoracotomy	18 (3.3%)	99 (18.0%)	95 (17.3%)	273 (49.7%)
VATS	10 (1.8%)	10 (1.8%)	15 (2.7%)	29 (5.3%)
Place of tumor relapse					0.271
Intrathoracic metastases	2 (1.5%)	17 (12.7%)	14 (10.4%)	41 (30.6%)
Systemic metastases	4 (3.0%)	11 (8.2%)	18 (13.4%)	27 (20.1%)

Abbreviations: LN, lymph node; VATS, video-assisted thoracoscopic surgery.