Table 2.

Demographics of patients in the Negative lymph Node Metastases (LNM) and Positive LNM groups

Variables	Group		P value
	Negative LNM	Positive LNM
Number	215	69
Age (years)			0.118
Mean ± SD	61.27 ± 9.38	59.28 ± 8.49
Gender			0.997
Male	109	35
Female	106	34
Pathology			0.176
Squamous cell carcinoma	24	12
Adenocarcinoma	191	57
Tumor location			0.368
Right Upper Lobe	62	20
Right Middle Lobe	14	2
Right Lower Lobe	28	11
Left Upper Lobe	63	14
Left Lower Lobe	34	17
Mixed lobes	14	5
Differentiation			<0.001*
I	80	6
II	119	57
III	16	6
Tumor size (cm)			<0.001
Mean ± SD	2.28 ± 0.95	2.92 ± 0.87
Pleura invasion			0.033*
Absent	173	47
Present	42	22
Bronchus invasion			<0.001*
Absent	196	51
Present	19	18
Multicentric invasion			1 (Fish)
Absent	200	64
Present	15	5
Angiolymphatic invasion			0.263 (Fish)
Absent	209	65
Present	6	4
Neural invasion			1.0 (Fish)
Absent	214	69
Present	1	0

SD standard deviation

*P < 0.05