Thyroid Cancer Staging
Different clinical pathologic staging systems of patients with thyroid cancer help to estimate survival rates, the risks of recurrence and long-term outcomes. Moreover, they help to determine how, when and for how long to follow patients with thyroid cancer, as well as enable transparent communication among clinicians.
Thyroid cancer staging provides a useful and consistent terminology that physicians can use to describe the extent of a cancer and how far it has spread to other tissues and organs in a patient’s body. Before assigning a stage to a cancer, physicians thoroughly analyze the results of all diagnostic tests, including physical examinations, biopsies, imaging scans and blood tests. At Moffitt Cancer Center, this process is performed collaboratively by a multispecialty team of experts. Each patient receives the benefit of multiple expert opinions to help ensure the best possible care.
One widely used classification system for thyroid cancer staging is the American Joint Committee on Cancer TNM (tumor, node, metastasis) system. “T” refers to the size and location of the primary tumor, “N” indicates whether the cancer has spread to the lymph nodes and “M” specifies whether the cancer has metastasized to other areas of the body. Each of these three categories is assigned a number ranging from zero to four, with higher numbers indicating more extensive cancers. TNM staging system is used to estimate survival in patients with thyroid cancer.
After designating appropriate TNM values, the experts at Moffitt review this information. The combined values correspond to one of four thyroid cancer staging categories, which are labeled stage 1 through stage 4, with higher numbers relating to more advanced cancers.
Differentiated thyroid cancer (papillary and follicular) is one of the few cancers that are staged by age. Patients under 55 years old can be only stage 1 or 2, patients over 55 years old can have stage 3 and 4 as well. All patients with anaplastic thyroid cancer are stage 4. Patients with medullary thyroid cancer are not staged by age.
While a cancer’s stage can be a useful benchmark, it does not paint a complete picture, nor can it conclusively predict a patient’s outcome. In general, the prognosis for a patient with thyroid cancer is usually excellent when the cancer is caught early and well managed.
The risk stratification system was developed by American Thyroid Association (ATA) to estimate the risk of recurrence in patients with differentiated thyroid cancer. Patients are classified as low, intermediate, and high risk. ATA risk stratification system helps to guide initial management in patients with papillary and follicular thyroid cancers.
Dynamic risk stratification is used during follow-up to determine response to previous therapy and long-term clinical outcomes as initial risk can change overtime. Patients may have no evidence of disease (excellent response), persistent tumor markers (biochemical incomplete response), persistent or recurrent metastatic disease (structural incomplete response) or indeterminate response with nonspecific findings.
At Moffitt Cancer Center, we practice individualized management based on patients’ staging and risks. To learn more about our thyroid cancer services, please call 1-888-663-3488, or request to schedule an appointment online.