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 for thyroid cancer.

There are different types of thyroid cancer. The number staging for medullary thyroid cancer is different to the staging system for other types of thyroid cancer. This page is about staging medullary thyroid cancer.

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 your cancer:

• is completely inside the thyroid and is no more than 2cm across
• hasn’t spread to the lymph nodes or other parts of the body

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

Stage 2

Stage 2 cancer is 2 cm or more and hasn't spread to nearby lymph nodes or to other parts of the body. It can mean one of the following.

Your cancer is:

• completely inside your thyroid and is between 2cm and 4cm
• completely inside your thyroid but is larger than 4cm
• any size and has grown slightly outside the thyroid into the surrounding muscles

In TNM staging this is the same as:

• T2, N0, M0
• T3, N0, M0

Stage 3

Stage 3 means that your cancer:

• is any size inside the thyroid or has just started to grow outside the thyroid into the surrounding muscle
• 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, N1a, M0.

Stage 4

Stage 4 is divided into 3 groups -  4A, 4B and 4C.

Stage 4A

Stage 4A means different things.

It can mean your cancer:

• is any size and is either completely inside your thyroid or has grown into the surrounding muscles
• 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.

Or it can mean your cancer:

• has grown beyond the thyroid gland and into nearby tissues of the neck such as the voice box, windpipe (trachea) or food pipe (oesophagus)
• 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. 

Stage 4B

Stage 4B means your cancer:

• has grown into the area surrounding the bones of the spine or into nearby large blood vessels
• 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 your 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