Most patients with thyroid cancer have the cancer contained in the thyroid at the time of diagnosis. However, about 30% of patients will have metastatic cancer, which is cancer that has spread to other parts of the body. The most common sites for metastasis are the lungs, bones, liver, and brain. In metastatic patients, specific death from thyroid cancer accounted for 73.2%.
Metastatic thyroid cancer, also known as stage 4 thyroid cancer, is the most advanced stage of the disease. Symptoms usually appear at an earlier stage and can often be detected before thyroid cancer has metastasized. Cancer cells that spread can be found when you are first diagnosed or can be found after treatment. The vast majority of thyroid cancers never spread.
If you or someone you love has thyroid cancer, you'll want to know what treatments are available and what to expect. Locally advanced and metastatic thyroid cancer has spread to other parts of the neck or to other parts of the body. After successful treatment, your health care provider may recommend follow-up appointments to look for signs that thyroid cancer has spread.
Several tests may be performed to help your doctor determine if the cancer has spread beyond the thyroid and outside the neck. Imaging tests such as CT and MRI scans can detect small thyroid cancers and show if your condition has changed or if the cancer has recurred (returned). Family members may also be tested to determine if they have an increased risk of medullary thyroid cancer.
Well-differentiated tumors (papillary thyroid cancer and follicular thyroid cancer) can be treated and can usually be cured. Radioactive iodine (RAI) is taken by mouth and builds up in any remaining thyroid tissue, including thyroid cancer cells that have spread to other parts of the body. Multiorgan distant metastases confer worse disease-specific survival in differentiated thyroid cancer.
If you are diagnosed with thyroid cancer, it is important to understand your treatment options and what to expect from follow-up care. Knowing the signs of metastasis can help you get early treatment if needed.