Staging

Your doctor will do some tests and tell you the stage of your cancer. This shows them how big the cancer is and whether it has spread. They can then decide on the best treatment for you.

There are two ways of staging thyroid cancer:

  • TNM staging – T describes the size of the cancer; N describes whether the cancer has spread to the lymph nodes and M describes if the cancer has spread to other parts of the body.
  • Number staging uses the information from the TNM system to give an overall number stage of the cancer. People under 45 with papillary or follicular thyroid cancer will have either stage 1 or stage 2 cancer. People over 45 may have up to stage 4 cancer.

The staging of thyroid cancer is complicated. Your doctor or nurse can explain it to you in more detail and answer any questions you may have.

Staging thyroid cancer

The  stage of a cancer describes its size and if it has spread from where it started. The stage of your thyroid cancer helps your doctors decide what treatment is best for you. 

There are different ways of staging cancers. The most common staging system is the TNM system.


TNM staging

T describes the size of the tumour and whether it has spread into nearby tissues around the thyroid gland. There are four levels. They range from T1, where the tumour is less than 2cm and hasn’t grown outside the thyroid gland, to T4, where the tumour is of any size and has spread to nearby tissues.

N describes whether the cancer has spread to the lymph nodes close to the thyroid gland. There are two levels:

  • N0 – the lymph nodes aren’t affected
  • N1 – the cancer has spread to lymph nodes close to the thyroid gland or in the neck or chest area

M describes whether the cancer has spread to other parts of the body, such as the lungs or the bones (metastatic or secondary cancer).


Number stages

Doctors often combine the information from the TNM system into an overall number stage, for example stage 2.

Unlike most cancers, papillary and follicular thyroid cancer are also staged according to the age of the person.

Papillary or follicular thyroid cancer in people aged under 45

Stage 1

The tumour can be of any size and nearby lymph nodes may be affected. But the tumour has not spread to other parts of the body.

Stage 2

The tumour is any size and has spread to other parts of the body, such as the bones or lungs.

There is no stage 3 or 4 thyroid cancer for people in this age group.

Papillary or follicular thyroid cancer in people aged 45 and over

Stage 1

The tumour is no bigger than 2cm and hasn’t grown outside the thyroid gland. There is no spread to the lymph nodes or to other parts of the body.

Stage 2

The tumour is between 2–4 cm and hasn’t grown outside the thyroid gland. The cancer has not spread to the lymph nodes or other parts of the body.

Stage 3

The tumour is bigger than 4cm and hasn’t grown outside the thyroid gland.

Or the tumour is any size and has spread just outside the thyroid gland. It has spread to nearby lymph nodes in the neck. It has not spread to other parts of the body.

Stage 4A

The tumour is any size and has spread into surrounding parts of the neck (such as the muscles, nerves or blood vessels). It may or may not have spread to the lymph nodes, but has not spread to other parts of the body.

Or the tumour is any size and may have spread just outside the thyroid gland. It has spread to lymph nodes in the neck away from the thyroid or in the upper chest. It has not spread to other parts of the body.

Stage 4B

The tumour is any size and has spread to other parts of the neck but not to other parts of the body.

Stage 4C

The cancer has spread to other parts of the body, such as the lung or bones. 

The staging of thyroid cancer is complicated. If you would like more information you can ask your doctor or nurse to explain it in more detail.


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