Table 1. The clinicopathological characteristics of all 44 patients.

Clinicopathological characteristics	No.
No.	44
Gender
Male	44
Female	0
Age
≥60	26
<60	18
Smoking status
Yes	23
No	21
Primary tumor
T1	15
T2	19
T3	6
T4	4
Regional lymph nodes
N0	29
N1	8
N2	7
N3	0
Metastasis
M0	44
M1	0
Differentiation
Well differentiated	8
Moderately differentiated	18
Poorly differentiated	18
TNM stage
I	23
II	12
III	9
IV	0