| Pathological tissue typing | Smoking | No smoking | ||
| n | % | n | % | |
| Squamous cell carcinoma | 414 | 49.2 | 146 | 32.5 |
| Small cell carcinoma | 54 | 6.4 | 35 | 7.8 |
| Adenocarcinoma | 264 | 31.4 | 258 | 57.5 |
| Large cell carcinoma | 68 | 8.1 | － |
|
| Adeno-squamous | 33 | 3.9 | 10 | 2.2 |
| Carcinoid | 8 | 1.0 | － |
|