Staging and Grading
What is Staging?
Once your doctor has diagnosed cancer, it important to find out how big the cancer is and where it started to grow. They need to see if the cancer has spread to the lymph nodes in the neck (nodal metastases) or other parts of the body such as the lungs, liver or bone (distant metastases). The term used to describe where the cancer has started to grow is called ‘primary’ and if it spreads to other parts of the body, it is called a ‘secondary’ or ‘metastases’. This is called staging. Staging a cancer is important because it helps your doctor to choose the best treatment for you.
The TNM System
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.
| T | stands for the size of the cancer. A T value can range from 1 (small cancer) to 4 (large cancer). |
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| N | indicates whether the cancer has spread to the lymph nodes. An N value can range from 0 (cancer has not spread to the lymph nodes) to 3 (cancer that has spread to lymph nodes in other parts of the body). |
| 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 (1), II (2), III (3) and IV (4).
The staging is complicated but cancers may be described as:
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Early cancer: these are Stage I or II cancers which are small (less than 4cm in size) that have not spread.
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Advanced cancer: Stage III or IV cancers are bigger (more than 4cm), have grown into nearby tissue, spread to lymph nodes, or spread to other parts of the body.
It is important to know that the staging systems for head and neck cancer are not very good at predicting the chances of cure for one person. For example, Stage III (3) or IV (4) cancers may include many groups of people where the chances of cure are very good but also others where the cancer may not be curable. It is important you discuss the stage of your cancer with your doctors to understand what it means for you.
What is Grading?
Your doctor will also be interested in the grade of the cancer. Grading refers to how quickly a cancer is likely to grow and spread. The grade of the cancer is determined by a pathologist who examines a 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.
| Grades of Cancer | |
|---|---|
| Grade 1 | Means the cancer cells look almost like normal cells and usually grow slowly. The term used to describe this appearance is well differentiated |
| Grade 2 | Means the cancer cells don't look like normal cells. The term used to describe this is moderately differentiated |
| Grade 3 or 4 | Means the cancer cells look very abnormal and may grow and spread fast. This is called poorly differentiated or undifferentiated |
