What is staging?
Once your doctor has made the diagnosis of cancer, it is important that they assess the extent (or stage) of the cancer. Staging a cancer is important because it helps your doctor to choose the best treatment for you. It also gives information about the chances of cure. The stage is based on the size of the cancer, whether it has invaded into nearby areas of the body and whether it has spread to lymph nodes in the neck (called lymph nodal metastases) or other sites in the body such as the lungs, liver or bone (called distant metastases).
The TNM (Tumour, Node, Metastases)
system is used to stage cancer. This system is used to summarise information about the size of the cancer and whether it has spread to lymph nodes at other parts of the body.
|The TNM system
||T stands for the size of the cancer. A T value can range from 1 (small cancer) to 4 (large cancer).
||N indicates whether the cancer has spread to the lymph nodes. Where there is no cancer in the lymph nodes, the N value is 0. An N value can range from 1 to 3, depending on the size and number of cancerous lymph nodes.
||M stands for distant metastases, or whether the cancer has spread to other parts of the body outside the head and neck. An M value can be either 0 (cancer has not spread to other parts of the body) or 1 (cancer has spread to other parts of the body).
Once the values for T, N and M have been worked out, they are combined to give an overall score between 1 and 4. Your doctor may write these as Roman numerals: I, II, III and IV.
Staging is complicated but in broad terms cancers may be described as:
- Early stage cancer (Stage I or II cancers), which are small (less than 4cm in size) and have not spread to the lymph glands or other parts of the body.
- Advanced stage cancer (Stage III or IV cancers), which are more advanced due to their size (more than 4cm), have spread to nearby parts of the body, the lymph nodes or other parts othe body.
It is important to know that staging of salivary gland cancer may not accurately predcit the chance of cure. This is partly because the chance of cure, often depends on the type of salivary gland cancer and its grade. One type of salivary gland cancer called adenoid cystic cancer commonly spreads to the lungs, but patients with this type of cancer may for live many years without any problems. Other high-grade salivary gland cancers are more difficult to treat once they have spread to other parts of the body. It is important that you discuss the stage of your cancer with your doctor to understand what it means for you.
The chance of cure depends on both the type of cancer and the stage. It is important to know that most patients with advanced salivary gland cancer (even stage III or IV) can be cured.
What is grading?
Staging and grading are not the same. Your doctor may also be interested in the grade of the cancer. Grading refers to the
growth pattern of the cancer. The grade of the cancer is determined by a pathologist who examines the biopsy sample under a microscope. The pathologist determines the grade of the cancer by how the cells look. The grade can be used to estimate how quickly the cancer is likely to grow and spread.
Working out the type and grade for a salivary gland cancer can be difficult. Sometimes doctors can disagree. Often, the grade and type of cancer can’t be decided upon until the whole cancer is removed. Identifying the grade of a cancer is important because it helps your cancer care team to work out the best treatment for your cancer.