Find out about tumour, node and metastasis (TNM) staging for nasal cavity cancer.
What TNM staging means
TNM stands for tumour, node and metastasis. The system describes:
- the size of a primary tumour (T) and how far it’s grown locally
- whether the cancer has spread to the lymph nodes (N)
- whether the cancer has spread in the bloodstream to a different part of the body (M)
T1 means the tumour is only in one part of the nasal cavity, but it may have grown into the bones of the nasal cavity.
T2 means the tumour has begun to grow into other nasal or paranasal cavities.
T3 means the tumour has spread into the bone of the eye socket, palate or maxillary sinus.
T4 means the tumour has spread into other nearby structures such as the eye, skull, brain, skin of the nose or cheek, sphenoid or frontal sinuses or nearby nerves.
There are 4 main lymph node stages in cancer of the nasal cavity, although N2 is divided into 3 parts - 2a, 2b and 2c.
The important points here are whether there is cancer in any of the lymph nodes, and if so, how big they are and where they are:
- N0 means there are no lymph nodes containing cancer cells
- N1 means there are cancer cells in one lymph node on the same side of the neck as the tumour, but the node measures 3cm across or less
- N2a means there is cancer in one lymph node, on the same side of the neck, that is more than 3cm across but no more than 6cm
- N2b means there is cancer in more than one lymph node on the same side of the neck, but none of them are more than 6cm across
- N2c means there is cancer in lymph nodes on the other side of the neck (or on both sides) but none are more than 6cm across
- N3 means that one or more nodes contain cancer and at least one node is more than 6cm across
There are 2 stages to describe spread of cancer of the nasal cavity to other parts of the body:
- M0 means there is no cancer spread to other parts of the body
- M1 means the cancer has spread to other parts of the body, such as the lungs, brain or liver
Together, the T, N and M stages give a complete description of the stage of your cancer. For example, if you have a T2, N0, M0 cancer of the nasal cavity, you have a tumour that has begun to grow into other parts of the nasal cavity, the lymph nodes are clear and there is no spread of your cancer to other parts of the body.
The grade of a cancer tells you how much the cancer cells look like normal cells. There are 3 grades of nasal cavity cancer:
- grade 1 (low grade) - the cancer cells look very much like the normal nasal cavity cells
- grade 2 (intermediate grade) - the cancer cells look slightly like normal nasal cavity cells
- grade 3 (high grade) - the cancer cells look very abnormal and very little like normal nasal cavity cells
The word differentiation means how developed or mature a cell is. You may hear your doctor describe grade 1 cancer cells as well differentiated.
Grade 2 cancer cells are moderately differentiated. Grade 3 cancer cells are poorly differentiated.
The grade of the cancer gives your specialist a guide as to how the cancer is likely to behave. Low grade cancers are usually slower growing and less likely to spread.
High grade cancers are likely to be faster growing and are more likely to spread. This is only a guide. Your specialist will consider all your test results when deciding which treatment is best for you.