Staging is the clinical or pathological process of investigation
of the extent of tumor. In general, it is based on clinical, radiological,
and operative information. Staging is used to determine the plan
of treatment and preoperative assessment to the patient and allows
making decisions regarding adjuvant therapy. Besides, it also provides
useful prognostic information. Furthermore, it also provides a basis
for comparison of treatment outcomes between different centers.
TNM system
The TNM classification is the most widely used system for staging
of cancer. This system is a commentary on uniform use to describe
the anatomical extent of cancer. Below are definitions of TNM respectively:
T: refers to the extent of primary tumor,
N: refers to the extent of nodal metastases.
M: refer to the presence or absence of distant metastases.
| T - primary tumor |
| Tx |
Primary tumor can not be assessed |
| T0 |
No evidence of primary tumor |
| Tis |
Carcinoma in-situ |
| T1-4 |
Increasing size and local extent of primary tumor |
| N - regional lymph nodes |
| Nx |
Regional lymph nodes can not be assessed |
| N0 |
No regional lymph node metastases |
| N1-3 |
Increasing involvement of regional lymph nodes |
| M - distant metastases |
| Mx |
Distant metastases can not be assessed |
| No |
Distant metastases |
| M1 |
Distant metastases present |
|