Before we get into the stages of thyroid cancer, let’s take a quick look at some information about thyroid cancer.

What is thyroid cancer?

Thyroid cancer develops in the thyroid, a small butterfly-shaped gland in the neck. This gland produces the hormone thyroxine, which regulates your metabolism, or how your body uses energy. Thyroid hormones also help control body temperature, blood pressure, and heart rate. As a result, thyroid cancer is a type of endocrine cancer that is generally highly treatable with excellent cure rates.

Thyroid cancer begins in the thyroid, a small gland at the base of the neck, just above the windpipe.

Types of Thyroid Cancer

Thyroid cancer can be divided into four main types based on the type of thyroid cells affected:

• Papillary thyroid cancer: This is the most common type of thyroid cancer, accounting for about 80% of cases. This type of cancer grows slowly. Although papillary thyroid cancer often spreads to the lymph nodes in the neck, it responds very well to treatment. Papillary thyroid cancer is highly curable and rarely causes death.
• Follicular thyroid cancer: This is the second most common type of thyroid cancer, accounting for about 10% of cases. This cancer is more likely to spread to your bones and other organs, such as your lungs. Metastatic (spreading) cancer can be more difficult to treat.
• Medullary thyroid cancer: This is a less common type of thyroid cancer, accounting for about 5 to 10% of cases. One-quarter of people with medullary thyroid cancer have a family history of the disease. A genetic mutation may be the cause of this type of cancer.
• Anaplastic thyroid cancer: This is the rarest, most aggressive, and hardest-to-treat type of thyroid cancer, accounting for about 1% of cases. It can grow quickly, often spreading to surrounding tissues and other parts of your body.

How Thyroid Cancer Is Staged

The American Cancer Society has created a system that is most commonly used to describe the stages of thyroid cancer. It is called the “TNM” system and focuses on three things:

• T – tumor: How big and how large is the primary or primary tumor?
• N – lymph nodes: Has the cancer spread to nearby lymph nodes? Lymph nodes are bean-shaped cells that help your body fight infection.
• M – metastasis: Has the cancer spread or metastasized to other areas of the body or organs, specifically the lungs, liver, and bones?

After your doctor runs tests to find out what type of thyroid cancer you have, they will add a number to each letter listed above. The higher the number, the more advanced the cancer is. For example, T2 means the tumor is larger than T1.

Next, your doctor will group this information into stages. These are represented by Roman numerals I through IV. For the most severe cases, the letters “A,” “B,” and “C” are also used to indicate how far the cancer has spread. The type of cancer you have, as well as your age, will affect your stage to some extent.

Thyroid cancer stages are often divided based on the “TNM” system.

Thyroid Cancer Stages

Here are the stages of thyroid cancer, according to the type of thyroid cancer and the age of the patient:

Papillary and Follicular Thyroid Cancer

Patients under age 55:

• Stage I: The tumor can be any size. It may have spread to nearby tissues or nearby lymph nodes. But it has not spread to other parts of the body.
• Stage II: The tumor can be any size. The cancer may have spread to your lymph nodes. It has also spread to other parts of your body, such as the lungs or bones.

Patients 55 and older:

• Stage I: You have cancer only in your thyroid. The tumor is 2 centimeters (about the size of a dime) or smaller and has not spread.
• Stage II: You have cancer only in your thyroid. The tumor is larger but not anywhere else in your body.
• Stage III: The tumor is any size and has spread to tissues near your thyroid, or the tumor is smaller and has spread to nearby lymph nodes.
• Stage IV: If you are in stage IV, it means the cancer has spread. Your doctor assigns the letters “A,” “B,” and “C” to show how far it has spread.
• Stage IVA: The cancer has spread beyond your thyroid. It is now under the skin or affecting your larynx, esophagus, or trachea. A smaller tumor in more distant lymph nodes is also considered stage IVA.
• Stage IVB: The tumor has grown toward your spine or into nearby large blood vessels, like the carotid arteries. These carry blood to your brain, face, and neck. It may also have spread to your lymph nodes.
• Stage IVC: The cancer has spread beyond your thyroid and to distant sites in your body. It may be in your lungs, bones, and lymph nodes.

Thyroid cancer stages vary depending on age and type of cancer.

Medullary Thyroid Cancer

The following thyroid cancer stages apply to all patients with medullary thyroid cancer, regardless of their age.

• Stage I: The tumor is 2 centimeters or smaller. It is only in your thyroid.
• Stage II: It is larger than 2 centimeters and is only found in your thyroid. Or it is any size but has spread to tissues outside your thyroid. However, it has not spread to your lymph nodes.
• Stage III: It can be smaller or larger than 2 centimeters and can also be in tissues outside your thyroid. The cancer has now invaded the lymph nodes near your larynx and trachea.
• Stage IV: Like follicular and papillary thyroid cancers, stage IV means the cancer has spread to distant sites in your body, and the letters “A,” “B,” and “C” indicate where it has spread.

Anaplastic Thyroid Cancer

This is a type of thyroid cancer that grows quickly. For this reason, it is only described as stage IVA, IVB, or IVC. By the time your doctor finds it, it may have spread to your neck. Here’s what each stage means:

• Stage IVA: Cancer cells are in your thyroid. It may have spread to nearby lymph nodes.
• Stage IV: It has spread outside the thyroid, possibly to your lymph nodes.
• Stage IVC: It has spread to other areas of your body, such as your lungs and bones. It may also be in your lymph nodes.

Differentiated thyroid cancer is the fastest growing type of thyroid cancer.

So we have learned about the stages of thyroid cancer. Thyroid cancer is a type of cancer that can be treated. The prognosis for survival of thyroid cancer patients depends on the stage of cancer, the type of cancer and the level of response to treatment. Hopefully the article will help you in the process of taking care of your health.