Knowing the stage of your thyroid cancer can help doctors determine the most appropriate treatment options. It can also give you and your healthcare team an idea of what to expect in terms of outlook.
The
Doctors stage thyroid cancer from stage I to stage IV depending on how far along your cancer has progressed. Different staging systems are used for different types of thyroid cancer.
Keep reading to learn more about how the most common types of thyroid cancer are staged.
Thyroid cancer is most often staged using the
- T: How big the tumor is and whether it has spread to nearby tissues.
- N: Whether the cancer has spread into nearby lymph nodes.
- M: Whether the cancer has metastasized, meaning spread to distant tissues.
The AJCC staging system differs depending on which type of thyroid cancer you have. The
- Medullary thyroid cancer: Develops in special cells called C cells that produce the hormone calcitonin.
- Follicular thyroid cancer: A usually slow-growing cancer that develops in follicular cells. These cells produce and secrete triiodothyronine (T3) and thyroxine (T4).
- Papillary thyroid cancer: Develops in follicular cells and makes up
80% to 85% of thyroid cancers. It generally has the best outlook. - Anaplastic thyroid cancer: Makes up less than 2% of thyroid cancers but is the most aggressive type. It develops in follicular cells.
Knowing which stage you’re in helps doctors figure out what the best treatment option may be. It can also give you and your healthcare team the best idea of what to expect in terms of life expectancy and chances of being cured.
The overall 5-year relative survival rate for medullary thyroid cancer is
Here’s a look at the AJCC’s TNM system for medullary thyroid cancer:
| Stage | TNM groups | Description |
|---|---|---|
| I | T1 N0 M0 | T1: The cancer is smaller than 0.8 inches across and only found in the thyroid. N0: It has not spread to nearby lymph nodes. M0: It has not spread to distant body parts. |
| II | T2 N0 M0 | T2: The cancer is bigger than 0.8 inches but smaller than 1.6 inches across. It’s only found in the thyroid. N0: It has not spread to nearby lymph nodes. M0: It has not spread to distant body parts. |
| OR | ||
| II | T3 N0 M0 | T3: The cancer is larger than 1.6 inches across and is limited to the thyroid or has grown outside the thyroid but hasn’t spread to nearby tissues. N0: It has not spread to nearby lymph nodes. M0: It has not spread to distant body parts. |
| III | T1, T2, or T3 N1a M0 | T1 to T3: The cancer can be any size but hasn’t invaded tissues around your thyroid. N1a: The cancer has spread to lymph nodes in your neck. M0: The cancer hasn’t spread to any distant body parts. |
| IVA | T4a Any N M0 | T4a: The cancer is any size and has grown into nearby tissues such as your windpipe or voice box. Any N: It may or may not have spread to nearby lymph nodes. M0: It hasn’t spread to distant body parts. |
| OR | ||
| IVA | T1, T2, or T3 N1b M0 | T1 to T3: The cancer is any size and may have grown outside the thyroid. It hasn’t grown into any nearby structures. N1b: The cancer has spread to lymph nodes in your neck. M0: The cancer has not spread to distant body parts. |
| IVB | T4b Any N M0 | T4b: The cancer is any size and has either grown toward your spine or into major blood vessels nearby. Any N: The cancer may or may not have spread to lymph nodes. M0: The cancer has not spread to distant body parts. |
| IVC | Any T Any N M1 | Any T: The cancer is any size and may have grown into nearby structures. Any N: The cancer may or may not have spread into lymph nodes. M1: The cancer has spread into distant areas such as your liver, brain, or bone. |
Staging for papillary or follicular thyroid cancer depends on whether you’re over or under the age of 55. The overall 5-year relative survival rate for people with papillary thyroid cancer is nearly
| Stage | Age of diagnosis | TNM groups | Description |
|---|---|---|---|
| I | younger than 55 years | Any T Any N M0 | Any T: The cancer is any size. Any N: The cancer may or may not have spread to lymph nodes. MO: It hasn’t spread to distant areas. |
| OR | |||
| I | 55 years or older | T1 N0 or NX M0 | T1: The cancer is smaller than 0.8 inches across and is only found in your thyroid gland. N0 or NX: The cancer hasn’t spread to nearby lymph nodes or there isn’t enough information to assess if the cancer has spread to lymph nodes. M0: The cancer hasn’t spread to distant areas. |
| OR | |||
| I | 55 years or older | T2 N0 or NX M0 | T2: The cancer is larger than 0.8 inches across but smaller than 1.6 inches. It’s limited to your thyroid. N0 or NX: The cancer hasn’t spread to nearby lymph nodes or there isn’t enough information to assess if the cancer has spread to lymph nodes. M0: The cancer hasn’t spread to distant areas. |
| II | younger than 55 years | Any T Any N M1 | Any T: The cancer is any size. Any N: The cancer may or may not have spread to nearby lymph nodes. M1: The cancer has spread to distant body parts like your bone or internal organs. |
| OR | |||
| II | 55 years or older | T1 N1 M0 | T1: The cancer is smaller than 0.8 inches across and limited to the thyroid. N1: The cancer has spread to nearby lymph nodes. M0: The cancer hasn’t spread to distant areas. |
| OR | |||
| II | 55 years or older | T2 N1 M0 | T2: The cancer is larger than 0.8 inches across but smaller than 1.6 inches. It’s limited to your thyroid. N1: The cancer has spread to nearby lymph nodes. M0: The cancer hasn’t spread to nearby areas. |
| OR | |||
| II | 55 years or older | T3a or T3b Any N M0 | T3a or T3b: The cancer is larger than 1.6 inches across but limited to the thyroid or the muscles that support your thyroid. Any N: The cancer may or may not have spread into nearby lymph nodes. M0: The cancer hasn’t spread to distant sites. |
| III | 55 years or older | T4a Any N M0 | T4a: The cancer is any size and has grown beyond your thyroid into surrounding tissues such as your voice box or windpipe. Any N: The cancer may or may not have spread into nearby lymph nodes. M0: The cancer hasn’t spread to distant sites. |
| IVA | 55 years or older | T4b Any N M0 | T4b: The cancer has spread extensively beyond your thyroid toward your spine or into large blood vessels in the surrounding area. Any N: The cancer may or may not have spread into nearby lymph nodes. M0: The cancer has not spread to distant locations. |
| IVB | 55 years or older | Any T Any N M1 | Any T: The cancer is any size. Any N: The cancer may or may not have spread to nearby lymph nodes. M1: The cancer has spread to distant parts of your body. |
Anaplastic cancer has the poorest outlook of any thyroid cancer. Its 5-year relative survival rate is
| Stage | Stage grouping | Description |
|---|---|---|
| IVA | T1, T2 or T3a N0 or NX M0 | T1, T2, or T3a: The cancer can be any size as long as it’s contained to your thyroid. N0 or NX: The cancer hasn’t spread to nearby lymph nodes or there’s not enough information to know if it has. M0: The cancer has not spread to distant parts of your body. |
| IVB | T1, T2 or T3a N1 M0 | T1, T2, or T3a: The cancer can be any size as long as it’s contained to your thyroid. N1: The cancer has spread to nearby lymph nodes. M0: The cancer has not spread to distant parts of your body. |
| OR | ||
| IVB | T3b Any N M0 | T3b: The cancer is any size and has grown into the muscles that support your thyroid. Any N: The cancer may or may not have spread into nearby lymph nodes. M0: The cancer has not spread to distant parts of your body. |
| OR | ||
| T4 Any N M0 | T4: The cancer has grown beyond the thyroid gland and into nearby tissue such as your voice box or windpipe. It also may have grown toward your spine or large blood vessels nearby. Any N: The cancer may or may not have spread to nearby lymph nodes. M0: The cancer has not spread to distant parts of your body. | |
| IVC | Any T Any N M1 | Any T: The cancer can be any size. Any N: The cancer may or may not have spread to nearby lymph nodes. M1: The cancer has spread into distant body parts such as your bones or internal organs. |
Thyroid cancer is broken into stages depending on how far the cancer has progressed. The AJCC’s TNM staging for papillary or follicular thyroid cancer also considers your age.
Cancers in early stages are considered easier to treat and have a better outlook. Due to the aggressive nature of anaplastic thyroid cancer, it’s always considered stage IV.
Knowing what stage of cancer you’re in helps doctors understand how to best manage your cancer. It can also give you an idea of your chances of survival. Survival statistics are often based on old data, so your chances of survival might be better than statistics suggest.