| T | T1a | Invasion of lamina propria or muscular mucosa |
| T1b | Invasion of submucosa | |
| T2 | Invasion of muscularis propria | |
| T3 | Invasion of adventitia | |
| T4a | Resectable tumor invading pleura, pericardium or diaphragm | |
| T4b | Unresectable tumor invading aorta, airway, vertebrae etc | |
| N | N0 | No lymph nodes |
| N1 | One to two regional lymph nodes | |
| N2 | Three to six regional lymph nodes | |
| N3 | Seven or more regional lymph nodes | |
| M | M0 | No distant metastasis |
| M1 | Distant metastasis |
Define unresectable?
- Tumor contact more than 90 degrees
- Loss of periaortic fat
- Nodular soft tissue extension into major airways