The stage of cancer describes the amount of cancer in the body and its location, and is used to determine treatment. The more complex or higher the stage, the more advanced the cancer. One of the most common staging systems is the TNM Staging System developed by the American Joint Committee on Cancer (AJCC). Cancers such as brain, blood or bone marrow may not fit TNM staging and may use a different system. A doctor must stage the cancer.
Clinical Staging
Clinical staging occurs when physical examination, imaging (X-rays) tests and biopsies are used to determine the amount of cancer.
Pathologic Staging
When surgery is done on the tumor and a sample is removed, the pathologist in the laboratory examines the specimen. Pathologic staging combines with the information from clinical staging and may be more specific.
TNM Staging: T
The T in TNM staging refers to the location of the primary cancer tumor and local tumor growth. Additional letters or numbers are used to describe the tumor, including TX (the tumor cannot be evaluated), T0 (no evidence of primary tumor), Tis (carcinoma in situ-the tumor has not spread), and T1-4 (the size of the tumor).
TNM Staging: N
The N refers to lymph node spread from the primary cancer. NX means that the lymph nodes cannot be evaluated; N0 means there is no involvement of the lymph nodes; and, N1-N3 describes the number of lymph nodes affected and the extent of spread.
TNM Staging: M
When cancer spreads to other parts of the body, it is said to have metastasized. M0 means that there are no distant metastases, or the cancer has not spread. M1 means that cancer spread is evident in other parts of the body.
Stage 0
TNM combinations can be further grouped into broad categories. Stage 0 means that the cancer is only in the cells at the site of the tumor (carcinoma in situ).
Stage I, II, and III
As the numbers increase, the tumor or disease is greater. The cancer has spread to lymph nodes or to nearby organs.
Stage IV
When a disease is said to be Stage IV, it has spread to another organ in the body.
Restaging
The stage of cancer does not change from diagnosis unless the cancer comes back after treatment. Restaging is not common, but can be used to determine the best treatment at the time of disease recurrence.
