Staging classification
| Stage | TNM classification |
| IA | T1 N0 M0 |
| IB | T2 N0 M0 |
| IIA | T1 N1 M0 |
| IIB | T2 N1 M0 |
| T3 N0 M0 | |
| IIIA | T3 N1 M0 |
| T1 N2 M0 | |
| T2 N2 M0 | |
| T3 N2 M0 | |
| IIIB | T4 N0 M0 |
| T4 N1 M0 | |
| T4 N2 M0 | |
| T1 N3 M0 | |
| T2 N3 M0 | |
| T3 N3 M0 | |
| T4 N3 M0 | |
| IV | Any T Any N M1 |
TNM: tumour, node, metastasis