Table 2. Clinopahological data of 256 patients with primary non-small cell lung cancer.

Items	Case (n)	N2 skip-	N2 skip+	P Value
Gender				0.612
Male	184	151	33
Female	72	61	11
History of smoking				0.946
Yes	135	112	23
No	121	100	21
Tumor location				0.310
Upper lobe	138	112	26
Middle lobe	13	10	3
Lower lobe	99	87	12
Pathologic type				0.679
Adenocarcinoma	141	119	22
Squamous cancer	90	72	18
Others	25	21	4
Pleura involvement				0.570
Yes	73	62	11
No	183	150	33
Mode of surgery				0.469
Open	143	122	21
Small incision	22	18	4
Endoscopic	91	72	19
Age (years)				0.530
﹤65	182	149	33
≥65	74	63	11
T stage				0.122
T1	41	37	4
T2	178	149	29
T3	30	21	9
T4	7	5	2
Maximum tumor diameter				0.020
≤3 cm	69	63	6
>3 cm, ≤5 cm	116	98	18
>5 cm, ≤7 cm	41	30	11
>7 cm	30	21	9
Differentiation				0.898
Poorly	22	19	3
Moderately	182	150	32
Highly	52	43	9