Table 1. A comparison on characteristics of sN2 and nsN2 groups.

Quantity/Frequency	sN2 (n = 55)	nsN2 (n = 147)	p*
Gender			0.53
Male	50 (91%)	129 (88%)
Female	5 (9%)	18 (12%)
Comorbidities	18 (33%)	46 (31%)	0.49
N2 disease (LN)
2R	–	1 (0.7%)	0.54
3	2 (4%)	1 (1%)	0.12
4R	10 (18%)	22 (15%)	0.34
4L	–	4 (3%)	0.22
5	17 (31%)	45 (31%)	0.61
6	3 (5%)	11 (8%)	0.51
7	13 (22%)	40 (27%)	0.25
8	5 (9%)	12 (8%)	0.71
9	5 (9%)	11 (8%)	0.7
Tumor histology			0.23
Adenocarcinoma	26 (47%)	58 (39%)
Squamous cell carcinoma	25 (46%)	84 (57%)
Large-cell carcinoma	4 (7%)	5 (3%)
Pulmonary resection type
RUL	11 (20%)	21 (14%)	0.32
RML	1 (2%)	2 (1%)	0.56
RLL	6 (11%)	18 (12%)	0.83
RP	4 (7%)	14 (10%)	0.52
LUL	16 (29%)	29 (19%)	0.15
LLL	5 (9%)	15 (10%)	0.81
LP	12 (22%)	48 (33%)	0.13
T status			0.68
T1	15 (27%)	34 (23%)
T2	22 (40%)	54 (37%)
T3	9 (16%)	34 (23%)
T4	9 (16%)	25 (17%)
Stages			0.22
Stage IIIA	37 (67%)	88 (60%)
Stage IIIB	18 (33%)	59 (40%)
Complications	4 (7%)	18 (12%)	0.39

^*Pearson’s chi-square test.

LLL: left lower lobectomy; LN: lymph node; LP: left pneumonectomy; LUL: left upper lobectomy; RLL: right lower lobectomy; RML: right middle lobectomy; RP: right pneumonectomy; RUL: right upper lobectomy