What is thyroid cancer?
Cancer can start any place in the body. Cancer that starts in the thyroid is called thyroid cancer. It starts when cells in the thyroid grow out of control and crowd out normal cells. This makes it hard for the body to work the way it should.
Cancer cells can spread to other parts of the body. Cancer cells in the thyroid can sometimes travel to lungs and the bone and grow there. When cancer cells do this, it’s called metastasis (pronounced meh-TAS-tuh-sis). To doctors, the cancer cells in the new place look just like the ones from the thyroid.
Cancer is always named for the place where it starts. So when thyroid cancer spreads to the lung (or any other place), it’s still called thyroid cancer. It’s not called lung cancer unless it starts from cells in the lung.
Ask your doctor to use this picture to show you where your cancer is.
The thyroid gland
The thyroid gland is below the Adam’s apple (called the thyroid cartilage) in the front of the neck. In most people, you can’t see or feel the thyroid. It’s butterfly shaped, with 2 sides called lobes. A thin piece of tissue called the isthmus connects the lobes.
The job of the thyroid gland is to make hormones that help control heart rate, blood pressure, body temperature, and weight.
Are there different kinds of thyroid cancer?
There are 4 main types of thyroid cancer. They are listed below. Your doctor can tell you more about the kind you have. The four types are based on how the cancer cells look under a microscope. (Carcinoma is another name for cancer. It’s pronounced CAR-sin-O-muh.)
Papillary (pronounced PAP-uh-LAIR-ee) thyroid cancer is the most common kind of thyroid cancer. It may also be called differentiated (DIF-uhr-EN-she-A-tid) thyroid cancer. This kind tends to grow very slowly and is most often in only one lobe of the thyroid gland. Even though they grow slowly, papillary carcinomas often spread to the lymph (limf) nodes in the neck.
Follicular (fah-LICK-yuh-ler) carcinoma is the next most common type. It’s more common in countries where people don’t get enough iodine in their diet. These cancers do not tend to spread to lymph (limf) nodes, but they can spread to other parts of the body, like the lungs or bones.
Medullary (MED-you-LAIR-ee) carcinoma is a rare type of thyroid cancer. It starts in a group of thyroid cells called C-cells. C-cells make calcitonin (cal-suh-TOE-nin), not thyroid hormone. Calcitonin is a hormone that helps control the amount of calcium in blood.
Anaplastic (an-UH-plas-tik) carcinoma is a rare form of thyroid cancer. It often spreads quickly into the neck and to other parts of the body, and is very hard to treat.
Questions to ask the doctor
- Why do you think I have cancer?
- Is there a chance I don’t have cancer?
- Would you please write down the kind of cancer you think I might have?
- What will happen next?
How does the doctor know I have thyroid cancer?
Tests that may be done
Most thyroid (THY-royd) cancers are found when patients see a doctor because of new neck lumps (called nodules [NOD-yools]). Sometimes doctors find neck lumps during a check-up. Yet other times thyroid cancer may be found during an ultrasound test for other health problems.
If signs are pointing to thyroid cancer, more tests will be done. Here are some of the tests you may need:
Blood tests: Blood tests alone can’t tell if a thyroid lump is cancer. But they can help show if the thyroid is working the way it should.
Ultrasound: For this test, a small wand is moved over the skin in front of your neck. It gives off sound waves and picks up the echoes as they bounce off the thyroid gland. The echoes are made into a picture on a computer screen. How a lump looks on ultrasound can sometimes help tell if it’s cancer, but ultrasound can’t tell for sure.
Radioiodine scan: For this test, a low dose of radioactive iodine (called I-131) is swallowed or put into a vein. Over time, the iodine is absorbed by the thyroid gland. A special camera is then used to see where the radioactivity is. Nodules that that have less iodine than the rest of the thyroid can sometimes be cancer.
CT scan: This is also called a “CAT scan.” It’s a special kind of x-ray that takes detailed pictures of the thyroid and can show if the cancer has spread.
MRI scan: This test uses radio waves and strong magnets instead of x-rays to take pictures. MRI scans can be used to look for cancer in the thyroid, or cancer that has spread.
PET scan: In this test, you are given a special type of sugar that can be seen inside your body with a camera. If there is cancer, this sugar shows up as “hot spots” where the cancer is found. This test can be very useful if your thyroid cancer is one that doesn’t take up radioactive iodine.
In a biopsy (BY-op-see), the doctor takes out a small piece of tissue to check it for cancer cells. A biopsy is the only way to tell for sure if you have cancer.
The most common kind of thyroid biopsy is a fine needle aspiration (FNA). To do this, the doctor will put a thin, hollow needle right into the nodule to take out some cells and a few drops of fluid to test for cancer cells.
If the diagnosis is not clear after an FNA biopsy, you might need another kind of biopsy to get more cells to test.
Questions to ask the doctor
- What tests will I need to have?
- Who will do these tests?
- Where will they be done?
- Who can explain them to me?
- How and when will I get the results?
- Who will explain the results to me?
- What do I need to do next?
How serious is my cancer?
If you have thyroid cancer, the doctor will want to find out how far it has spread. This is called staging. You may have heard other people say that their cancer was “stage 1” or “stage 2.” Your doctor will want to find out the stage of your cancer to help decide what type of treatment is best for you.
The stage describes the growth or spread of the cancer through the thyroid gland. It also tells if the cancer has spread to other organs of your body that are close by or farther away.
Your cancer can be stage 1, 2, 3, or 4. The lower the number, the less the cancer has spread. A higher number, like stage 4, means a more serious cancer that has spread beyond the thyroid gland. Be sure to ask the doctor about the cancer stage and what it means for you.
Questions to ask the doctor
- Do you know the stage of the cancer?
- If not, how and when will you find out the stage of the cancer?
- Would you explain to me what the stage means in my case?
- Based on the stage of the cancer, how long do you think I’ll live?
- What will happen next?
What kind of treatment will I need?
There are many ways to treat thyroid cancer but surgery is the main treatment. The treatment plan that’s best for you will depend on:
- The stage of the cancer
- The chance that a type of treatment will cure the cancer or help in some way
- Your age
- Other health problems you have
- Your feelings about the treatment and the side effects that come with it
Depending on the type and stage of your thyroid cancer, you may need more than 1 type of treatment.
Surgery for thyroid cancer
Most patients with thyroid cancer have some type of surgery (SUR-jur-ee). Surgery is done to take out the tumor and all or part of the thyroid gland. Sometimes lymph nodes are taken out from the neck, too.
Side effects of surgery
Any type of surgery can have risks and side effects. Be sure to ask the doctor what you can expect. If you have problems, let your doctors know.
Radioactive iodine treatment
Your thyroid gland absorbs nearly all the iodine in your body. When a high dose of radioactive iodine (RAI), also called I-131, is taken into the body it collects in thyroid cells. The radiation then destroys all the thyroid cells, even the ones that are cancer, with little effect on the rest of your body.
Side effects of RAI
Common side effects of RAI treatment are:
- Neck soreness and swelling
- Nausea and vomiting
- Swollen and sore salivary glands
- Dry mouth
- Taste changes
Radiation (pronounced RAY-dee-A-shun) uses high-energy rays (like x-rays) to kill cancer cells. This treatment may be used to kill any cancer cells that may be left after surgery.
Side effects of radiation treatments
If your doctor suggests radiation treatment, talk about what side effects might happen. Side effects depend on the type of radiation that’s used. The most common side effects of radiation are:
- Skin changes where the radiation is given
- Dry mouth
- Hoarse voice
- Feeling very tired (fatigue, which is pronounced fuh-TEEG)
Most side effects get better after treatment ends. Some might last longer. Talk to your cancer care team about what you can expect.
Chemo (pronounced KEY-mo) is the short word for chemotherapy (pronounced KEY-mo-THAIR-uh-pee) – the use of drugs to fight cancer. These drugs go into the blood and spread through the body. Chemo is given in cycles or rounds. Each round of treatment is followed by a break. Most of the time, 2 or more chemo drugs are given. Treatment often lasts for many months.
Chemo is not often used to treat thyroid cancer.
Side effects of chemo
Chemo can make you feel very tired, sick to your stomach, and cause your hair to fall out. But these problems go away after treatment ends.
There are ways to treat most chemo side effects. If you have side effects, be sure to talk to your cancer care team so they can help.
There are some newer drug treatments called “targeted therapy” that may be used for certain types of thyroid cancer. This is not the same as chemo because these drugs affect mainly cancer cells and not normal cells in the body. They may work even if other treatment doesn’t. They may cause fewer side effects.
Thyroid hormone replacement
If all or part of the thyroid gland is taken out with surgery or destroyed with radiation, you will need to take pills of thyroid hormone to replace the missing thyroid hormones your body needs.
Taking higher doses of thyroid hormone may also help keep some kinds of thyroid cancer from coming back.
Clinical trials are research studies that test new drugs or other treatments in people. They compare standard treatments with others that may be better.
If you would like to be in a clinical trial, start by asking your doctor if your clinic or hospital takes part in clinical trials. You can also call our clinical trials matching service at 1-800-303-5691 or go online at www.cancer.org/clinicaltrials to find studies near you.
Clinical trials are one way to get the newest cancer treatment. They are the best way for doctors to find better ways to treat cancer. If your doctor can find one that’s studying the kind of cancer you have, it’s up to you whether to take part. And if you do sign up for a clinical trial, you can always stop at any time.
What about other treatments that I hear about?
When you have cancer you might hear about other ways to treat the cancer or treat your symptoms. These may not always be standard medical treatments. These treatments may be vitamins, herbs, special diets, and other things. You may wonder about these treatments.
Some of these are known to help, but many have not been tested. Some have been shown not to help. A few have even been found to be harmful. Talk to your doctor about anything you’re thinking about using, whether it’s a vitamin, a diet, or anything else.
Questions to ask the doctor
- What treatment do you think is best for me?
- What’s the goal of this treatment? Do you think it could cure the cancer?
- Will treatment include surgery? If so, who will do the surgery?
- What will the surgery be like?
- Will I need other types of treatment, too?
- What’s the goal of these treatments?
- What side effects could I have from these treatments?
- What can I do about side effects that I might have?
- Is there a clinical trial that might be right for me?
- What about special vitamins or diets that friends tell me about? How will I know if they are safe?
- How soon do I need to start treatment?
- What should I do to be ready for treatment?
- Is there anything I can do to help the treatment work better?
- What’s the next step?
What will happen after treatment?
Most people do very well after treatment, but you may need follow-up care for the rest of your life. This is because most thyroid cancers grow slowly and can come back even 10 to 20 years after treatment. Your cancer care team will tell you what tests you need and how often they should be done.
Having cancer and dealing with treatment can be hard, but it can also be a time to look at your life in new ways. You might be thinking about how to improve your health. Call us at 1-800-227-2345 or talk to your cancer care team to find out what you can do to feel better.
You can’t change the fact that you have cancer. What you can change is how you live the rest of your life – making healthy choices and feeling as good as you can.
Anaplastic carcinoma (an-UH-plas-tik CAR-sin-O-ma): A rare, fast-growing type of thyroid cancer in which the cancer cells look very different from normal thyroid cells.
Biopsy (BY-op-see): Taking out a small piece of tissue to see if there are cancer cells in it.
Follicular carcinoma (fuh-LIH-kyoo-ler CAR-sin-O-ma): Cancer that starts in follicular cells in the thyroid. It grows slowly and is highly treatable.
Lobectomy (low-BEK-tuh-me): Surgery to remove a lobe (part) of an organ.
Lymph (limf) nodes: small, bean-shaped collections of immune system tissue found all over the body and connected by lymph vessels; also called lymph glands
Medullary carcinoma (MED-yoo-LAYR-ee CAR-sin-O-ma): Cancer that starts in the C-cells of the thyroid. The C-cells make a hormone called calcitonin (cal-suh-TOE-nin) that helps keep a healthy level of calcium in the blood.
Metastasis:( meh-TAS-tuh-sis): cancer cells that have spread from where they started to other places in the body
Nodules (NOD-yools): A small, solid lump that can be felt or seen on an imaging test.
Papillary carcinoma: (PA-pih-LAYR-ee CAR-sin-O-ma): The most common type of thyroid cancer. It grows slowly, often in 1 lobe of the thyroid gland. It often spreads to lymph nodes in the neck.
Thyroidectomy (THY-roy-DEK-toh-mee): Surgery to remove part or all of the thyroid gland.
Last Medical Review: March 11, 2016 Last Revised: March 11, 2016