Number stages for medullary thyroid cancer

The stage of a cancer tells you about its size and whether it has spread. Doctors use the number staging system and the TNM staging system.

The number staging system groups cancers into 4 groups, from stage 1 to 4. The higher the number the more the cancer has spread.

Stage 1

Stage 1 means that the tumour is 2 cm or less and hasn't grown outside the thyroid gland. It has not spread to nearby lymph nodes or other parts of the body.

In TNM staging, this is the same as T1, N0, M0.

Stage 2

Stage 2 means the tumour is 2cm or more and hasn't spread to nearby lymph nodes or other parts of the body.

The tumour is one of the following:

• between 2cm and 4cm and hasn't grown outside the thyroid. In TNM staging this is the same as T2, N0, M0.
• 4 cm or larger but is still within the thyroid. In TNM staging this is the same as T3, N0, M0
• any size and has grown slightly outside the thyroid into the surrounding muscles. In TNM staging this is the same as T3, N0, M0.

Stage 3

Stage 3 means that the tumour is any size inside the thyroid or has just started to grow outside the thyroid into the surrounding muscles. It has spread to lymph nodes close to the thyroid but not to other parts of the body. In TNM staging this is the same as T3, N0, M0.

Stage 4

Stage 4 is divided into 3 groups from A to C.

Stage 4A

Stage 4A means the tumour is one of the following:

• it has grown beyond the thyroid gland and into nearby tissues of the neck such as the voice box, windpipe (trachea) or food pipe (oesophagus). It may or may not have spread to nearby lymph nodes but hasn't spread to other parts of the body. In TNM staging this is the same as T4a, any N, M0. 
• it is any size within the thyroid or may have grown into the surrounding muscles. It has spread to the lymph nodes in the neck or behind the throat (retropharyngeal nodes) but not to other parts of the body. In TNM staging this is the same as T1-3, N1b, M0.

Stage 4B

Stage 4B means the tumour has grown into the area surrounding the bones of the spine or into nearby large blood vessels. It may or may not have spread to nearby lymph nodes but it hasn't spread to other parts of the body. In TNM staging this is the same as T4b, any N, M0.

Stage 4C

Stage 4C means the cancer has spread to other parts of the body, such as the liver or lungs. In TNM staging this is the same as any T, any N, M1.

Treatment

The stage of your cancer helps your doctor to decide which treatment you need. Treatment also depends on:

• your type of cancer (the type of cells the cancer started in)
• where the cancer is
• other health conditions that you have