Table 1.

General data

Characteristics	Cases
Gender
Male	209
Female	255
Age (years)
≤ 60	204
> 60	260
Smoking status
No	257
Yes	207
Primary tumor sites
Upper lobe	137
Middle and lower lobes	327
Histology
SCC	421
Ad	43
TNM stage
I+II	225
III+IV	239

Ad, adenocarcinoma; SCC, squamous cell carcinoma.