Once the cancer is confirmed in your thyroid, your physician will determine its stage. Knowing the stage of the cancer, your doctor will be able to determine the most appropriate treatment to fight the disease. A thyroid cancer stage is determined based on the size of the tumor and whether it has spread beyond the thyroid gland. Since aggressivity of thyroid cancer varies from one type to another, there are two types of staging.
There are two stages for papillary thyroid cancer and follicular thyroid cancer in patients under 45 years:
- Stage I – to this point, the cancer has not spread to distant sites of the body, but it can be any size and may have spread to the neck, upper chest and/or to nearby lymph nodes.
- Stage II – at this stage, the cancer has not only invaded the chest and/or nearby lymph nodes but also other remote sites of the body such as bones or lungs.
There are four stages for papillary thyroid cancer, follicular thyroid cancer and medullary thyroid cancer in patients 45 years and older.
- Stage I – the cancer is limited to the thyroid gland, and measuring 2 cm or less in diameter.
- Stage II – the cancer is still limited to the thyroid, but has increased in size, usually between 2 and 4 cm in diameter;
- Stage III – at stage 3, the size of the tumor is more than 4 cm in diameter and can have been spread outside the thyroid and/or lymph nodes in the neck without evading distant organs of the body.
- Stage IV– the tumor can be at any size, and has extended beyond the thyroid capsule to reach the lymph nodes in the neck and upper chest and other body parts, such as lungs or bones.