Stages and types of 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.
Find out more about 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.
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 the number stages of medullary thyroid cancer.
Read about number staging for other types of thyroid cancer
Stage 1 means the cancer:
is completely inside the thyroid and is no more than 2cm across
hasn’t spread to the or other parts of the body
In TNM staging, this is the same as T1, N0, M0.
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.
The 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 means that the 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 is divided into 3 groups - 4A, 4B and 4C.
Stage 4A means different things.
It can mean the 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 the 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 means the 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 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.
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
Last reviewed: 03 Aug 2023
Next review due: 03 Aug 2026
TNM staging shows the size of your cancer (T), whether it has spread to lymph nodes (N) and whether it has spread to other parts of your body (M).
The type of thyroid cancer refers to the type of cell the cancer started in. The stage of a cancer tells you its size and whether it has spread.
Possible treatments include surgery, radiotherapy, targeted drugs and chemotherapy. What treatment you have depends on your type and stage of thyroid cancer.
Survival for thyroid cancer depends upon the type and stage of your thyroid cancer. Survival is generally very good for papillary and follicular thyroid cancers.
Thyroid cancer is when abnormal cells in the thyroid gland start to divide and grow in an uncontrolled way.
The thyroid is a small butterfly shaped gland that makes and releases hormones. It’s found at the front of your neck in the lowest part.
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