Table 2.

Demographics of patients in the negative LNM and positive LNM groups

Variables	Group		p value
	Negative LNM (group I)	Positive LNM (group II)
Number	411	87
Age (years)
Mean ± SD	60.91 ± 7.19	59.91 ± 7.26	0.237
Gender
Male	301	66	0.613
Female	110	21
Tumor location
Cervical	15	1	0.147
Upper thoracic	71	19
Middle thoracic	212	36
Lower thoracic	113	31
Tumor size (cm)
Mean ± SD	1.73 ± 0.97	2.31 ± 1.09	<0.05*
Pathologic appearancea
Erosive type	85	14	0.175
Ulcerative type	98	25
Fungating type	61	23
Other types	53	13
Differentiationb
I	22	2	<0.05*
I–II	67	4
II	154	31
II–III	52	34
III	33	13
Depth of invasion
m1	43	0	<0.05* m1 to m2 vs m3 to sm3: p < 0.05 m1 to m3 vs sm1 to sm3: p < 0.05 m1 to m2 vs m3 to sm1 vs sm2 to sm3: p < 0.05
m2	36	1
m3	75	5
sm1	72	16
sm2	95	18
sm3	90	47
Multicentric invasion
Absent	404	83	0.095
Present	7	4
Angiolymphatic invasion
Absent	396	71	<0.05*
Present	15	16

SD standard deviation

*Statistically significant

^aData available in 372 patients

^bData available in 412 patients