Staging of thyroid cancer

Staging is the process of finding out if and how far a cancer has spread. The stage of a cancer is important in choosing the best treatment. The stage can also help predict the patient’s outlook (prognosis) and chance for a cure.

Staging is based on the results of the physical exam, biopsy, and imaging tests (ultrasound, radioiodine scan, CT scan, MRI, chest x-ray, and/or PET scan), which are described in the section, “How is thyroid cancer found?”

The most common system used to describe the stages of thyroid cancer is the American Joint Committee on Cancer (AJCC) TNM system. The stages of thyroid cancer are usually labeled using Roman numerals I through IV (1-4). As a rule, the lower the number, the less the cancer has spread. A higher number, such as stage IV (4), means a more advanced cancer. Unlike most other cancers, thyroid cancers are grouped into stages in a way that also takes into account the type of thyroid cancer and the patient’s age.

Recurrent cancer

Cancer that comes back after treatment is called recurrent (or relapsed). If thyroid cancer returns it is usually in the neck, but it might come back in a different part of the body (for instance, lymph nodes, lungs, or bones). The stage assigned stays the same even if the disease recurs.

If you have any questions about the stage of your cancer or how it affects your treatment options, be sure to ask your doctor.