Thyroid Cancer

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Thyroid Cancer

Topic Overview

What is thyroid cancer?

Thyroid cancer is a
disease that you get when abnormal cells begin to grow in your
thyroid gland. The thyroid gland is shaped like a butterfly and is located in
the front of your neck. It makes hormones that regulate the way your body uses
energy and that help your body work normally.

Thyroid cancer is an
uncommon type of cancer. Most people who have it do very well, because the
cancer is usually found early and the treatments work well. After it is
treated, thyroid cancer may come back, sometimes many years after
treatment.

What causes thyroid cancer?

Experts don't know what causes thyroid cancer. But like other cancers, changes in the DNA of your cells seem to play a role. These DNA changes may include changes that are inherited as well as those that happen as you get older.

People who have been
exposed to a lot of radiation have a greater chance of getting thyroid cancer.

A
dental X-ray now and then will not increase your chance of getting thyroid
cancer. But past
radiation treatment of your head, neck, or chest
(especially during childhood) can put you at risk of getting thyroid cancer.

What are the symptoms?

Thyroid cancer can cause
several symptoms:

  • You may get a lump or swelling in your neck.
    This is the most common symptom.
  • You may have pain in your neck and
    sometimes in your ears.
  • You may have trouble
    swallowing.
  • You may have trouble breathing or have constant
    wheezing.
  • Your voice may be hoarse.
  • You may have a
    frequent cough that is not related to a cold.

Some people may not have any symptoms. Their doctors may
find a lump or
nodule in the neck during a routine physical
exam.

How is thyroid cancer diagnosed?

If you have a
lump in your neck that could be thyroid cancer, your doctor may do a
biopsy of your thyroid gland to check for cancer
cells. A biopsy is a simple procedure in which a small piece of the thyroid
tissue is removed, usually with a needle, and then checked.

Sometimes the results of a biopsy are not clear. In this case, you may
need surgery to remove all or part of your thyroid gland before you find out if
you have thyroid cancer.

How is it treated?

Thyroid cancer is treated with
surgery and often with radioactive iodine. It rarely needs
radiation therapy or
chemotherapy. What treatment you need depends on your
age, the type of thyroid cancer you have, and the
stage of your disease. Stage refers to how severe the
disease is and how far, if at all, the cancer has spread.

Finding out that you have cancer can be overwhelming. It's common to feel scared, sad, or even angry. Talking to others who have had thyroid cancer may help. Ask your doctor about cancer support groups in your area.

Can thyroid cancer be prevented?

Most thyroid cancer cannot
be prevented.

One rare type of thyroid cancer, called
medullary thyroid cancer (MTC), runs in families. A genetic test can tell you
if you have a greater chance of getting MTC. If this test shows that you have
an increased risk, you can have your thyroid gland removed to reduce your risk for thyroid
cancer later in life.

Frequently Asked Questions

Learning about thyroid cancer:

Being diagnosed:

Getting treatment:

Living with thyroid cancer:

Cause

Experts don't know what causes thyroid cancer. Like other cancers, changes in the DNA of your cells seem to play a role. These DNA changes may include changes that are inherited as well as those that happen as you get older.

Symptoms

Thyroid cancer can cause many symptoms,
including:

  • A lump or swelling in your neck. This is the
    most common symptom.
  • Pain in your neck and sometimes in your
    ears.
  • Difficulty swallowing.
  • Difficulty breathing or
    constant wheezing.
  • Hoarseness that is not related to a
    cold.
  • A cough that continues and is not related to a cold.

Some people may not have any symptoms. Their doctors may
find a lump or nodule in the neck during a routine physical exam.

What Happens

Thyroid cancer
is a disease that occurs when abnormal cells begin to grow in the
thyroid gland. You may notice a lump in your neck and
then go to your doctor. Or your doctor may notice a lump during a routine
physical exam or on an imaging test that you are having for another health
problem.

Thyroid cancer is usually found before the cancer has
spread very far. This means that most people who are treated for thyroid cancer
do very well. After it is treated, thyroid cancer may come back, sometimes many
years after treatment.

Before starting your treatment, your
doctor needs to find out which type of thyroid cancer you have. A
biopsy can identify your type of cancer. During a
biopsy, a small piece of thyroid tissue is removed, usually with a fine needle. The
thyroid tissue cells are then examined under a microscope.

It is
also important to find out the
stage of your cancer. Staging is a way for your doctor
to tell how far, if at all, the cancer has spread. It also helps your doctor
decide what kind of treatment you need. Staging generally depends on the results of your radioactive iodine scan.

If you have your thyroid
gland surgically removed, you will probably need to take thyroid hormone medicine for the rest of your life to replace the hormones that were made by your thyroid. Taking it will help regulate your
metabolism and other body functions.

What Increases Your Risk

A risk factor for thyroid cancer is something that increases your chance of getting this cancer. Having one or more of these risk factors can make it more likely that you will get thyroid cancer. But it doesn't mean that you will definitely get it. And many people who get thyroid cancer don't have any of these risk factors.

The most common risk factors for thyroid cancer include:

  • Age.
  • Being female.
  • Exposure to high levels of radiation,
    such as after a nuclear power accident.
  • A personal or family history of thyroid disease or thyroid cancer.
  • A family history of conditions such as MEN (multiple endocrine neoplasia) 2a, MEN 2b,
    or FMTC (familial medullary thyroid carcinoma).
  • Being
    Asian.
  • A history of
    radiation treatments to the head, neck, or chest
    during childhood.
  • Other inherited medical conditions,
    such as
    Gardner's syndrome and
    familial polyposis.

One rare type of thyroid cancer, which is called
medullary thyroid cancer (MTC), runs in families. You
can inherit a specific
gene that increases your risk for
MTC.

When To Call a Doctor

Call your doctor if you have any
of the following symptoms:

  • A lump or swelling in your neck. This is the
    most common symptom of thyroid cancer.
  • Pain in your neck and
    sometimes in your ears that doesn't go away and is not caused by a cold or
    allergies
  • Hoarseness that is not related to a
    cold
  • Difficulty swallowing
  • Difficulty breathing or
    constant wheezing
  • A cough that continues and is not related to a
    cold
  • Bone pain

Who to see

Health professionals who can evaluate your symptoms
and help determine your risk for thyroid cancer include:

Thyroid cancer is usually treated by endocrinologists,
nuclear medicine specialists,
surgeons,
medical oncologists, and
radiation oncologists.

To prepare for your appointment, see the topic Making the Most of Your Appointment.

Exams and Tests

In order to diagnose
thyroid cancer, your doctor will ask about your
medical history and do a
physical exam.

Your doctor may check your vocal cords using a thin tube-like instrument that has a light (laryngoscope).

Your doctor may order a
CT scan or an
ultrasound to get a better look at your thyroid. If
your doctor thinks that the lump or nodule could be cancerous, he or she may
do a
fine needle biopsy of the thyroid gland.

You may also
have blood tests to check the levels of your thyroid-stimulating hormone (TSH), serum calcitonin, or carcinoembryonic antigen (CEA).

Other tests may be done before, during, or after your
treatment for thyroid cancer.

In some cases, an MRI, a chest X-ray, a CT scan, or a
PET scan may be done.

If you have
medullary thyroid cancer (MTC), a
CT scan of the chest and belly and a
bone scan may also be needed.

Early detection

At this time there are not any screening tests for thyroid cancer that work well for people at average risk. Talk to your doctor about whether you need
to be screened for thyroid cancer.

People who have a family
history of medullary thyroid cancer (MTC) may want to have a
genetic test to look for a gene change called an RET
mutation. Before you have the test, it is a good idea to talk with a
genetic counselor. He or she can help you understand
what your test results may mean.

Treatment Overview

The goal of treatment
for thyroid cancer is to get rid of the cancer cells in your body. How this is
done depends on your age, the
type of thyroid cancer you have, the
stage of your cancer, and your general health.

Most people have surgery to remove part or all of the thyroid gland.
Sometimes a suspicious lump or
nodule has to be surgically removed before you will
know if you have cancer or not.

After surgery, you may need
treatment with radioactive iodine to destroy any remaining thyroid tissue. When
you no longer have all or part of your thyroid gland, you will probably need to
take thyroid hormone medicines for the rest of your life. These medicines
replace necessary hormones that are normally made by the thyroid gland and
prevent you from having
hypothyroidism—too little thyroid hormone.

For more
information on hypothyroidism, see the topic
Hypothyroidism.

Initial treatment

Your treatment for
thyroid cancer may include:

  • Surgery to remove the part of the
    thyroid gland that contains cancer. Removing one part (lobe) is called a
    lobectomy. Removing both lobes is called a total thyroidectomy.
    Removing all but a very small part of the thyroid is called a near-total thyroidectomy. Lymph nodes may also be removed during
    surgery.
  • Radioactive iodine, which is used after surgery to
    destroy any remaining thyroid tissue. After you have your thyroid surgically
    removed, you may have to wait several weeks before having radioactive iodine
    treatment to destroy any remaining thyroid tissue. During the waiting period,
    you may have symptoms of hypothyroidism such as fatigue, weakness, weight gain,
    depression, memory problems, or constipation.
  • Thyroid-stimulating hormone (TSH) suppression therapy.
    TSH suppression therapy reduces the TSH in your body, which may help prevent
    the growth of any remaining cancer cells.

If thyroid cancer is
advanced when it is diagnosed, initial treatment may also include
chemotherapy or
radiation therapy.

Additional information about thyroid cancer is provided by the National Cancer Institute at www.cancer.gov/cancertopics/types/thyroid.

Ongoing treatment

After treatment for
thyroid cancer, you may need to take
thyroid hormone medicine for the rest of your life to
replace the hormones that your body no longer makes. You will also need
follow-up visits with your doctor every 6 to 12 months. In addition to
scheduling regular visits, be sure to call your doctor if you notice another
lump in your neck or if you have trouble breathing or swallowing.

At your follow-up visits, your doctor may order a blood test to measure your
thyroid-stimulating hormone (TSH) level. This test
helps your doctor know if you are taking the right amount of thyroid hormone
medicine. Your doctor may order other tests, such as a
radioiodine scan, X-rays,
or a CT scan.

Side effects of treatment

The side effects of surgery for thyroid cancer are usually mild and last a couple of days. Your doctor will talk to you about medicine you can take if you are having pain. You will likely need to take
thyroid hormone medicine for the rest of your life to
replace the hormones that your body no longer makes.

The most important side effect of radioactive iodine therapy (RAI) is that you will become radioactive for a period of time. Your doctor will give you written instructions to follow to prevent exposing others to radiation. For more information, see Radioactive Iodine.

Thyroid hormone therapy rarely causes side effects when you have the right dose. Too much or too little thyroid hormone can cause side effects.

Taking high doses of thyroid hormone may cause a rapid or irregular heartbeat. High doses taken over time may also cause weakness in your bones (osteoporosis).

Home treatment may help you manage your side effects.

Treatment if the condition gets worse

Thyroid cancer may come back (recur). If thyroid
cancer does recur, it may be found during a physical exam, on an ultrasound, or
as a result of increasing
thyroglobulin levels. Unlike other types of recurrent
cancer, recurrent thyroid cancer is often cured, especially if it has spread
only to the
lymph nodes in the neck.

Recurrent thyroid cancer or
thyroid cancer that has spread (metastasized) to other parts of the body may be treated with surgery, radioactive iodine, radiation, or chemotherapy.

Clinical trials

Your doctor may talk to you about being in a clinical trial. For some people with thyroid cancer, taking part in a clinical trial may be the best treatment choice. Clinical trials for thyroid cancer are looking at targeted therapy with tyrosine kinase inhibitors.

Palliative care

Palliative care is a kind of care for people who have a serious illness. It's different from care to cure your illness. Its goal is to improve your quality of life—not just in your body but also in your mind and spirit.

You can have palliative care along with treatment to cure your illness. You can also have it if treatment to cure your illness no longer seems like a good choice.

Palliative care providers will work to help control pain or side effects. They may help you decide what treatment you want or don't want. And they can help your loved ones understand how to support you.

If you're interested in palliative care, talk to your doctor.

For more information, see
the topic
Palliative Care.

Prevention

Most cases of thyroid cancer cannot be prevented.

You may be much more likely to get medullary thyroid cancer (MTC) if you have a gene carried by some families. A
genetic test can show if you carry this gene. If your test is positive for the gene, you may want to talk with your doctor about having your thyroid removed to prevent getting thyroid cancer later in life.

Home Treatment

There are certain things you can do to
feel better or to reduce the side effects of your treatment for
thyroid cancer. Healthy habits such as eating a balanced diet and getting enough sleep and exercise may help control your symptoms. If you have chemotherapy, your doctor may also give you medicines to control and prevent nausea and vomiting.

You can try home treatments:

  • For nausea or vomiting, such as ginger or peppermint tea, gum, or candy.
  • For feeling very tired. If you lack energy or become weak easily, try to manage your energy and get extra rest. You may feel most tired
    at the end of treatment or just after treatment is completed.
  • For a dry mouth. Take frequent sips of water throughout the day. Sugar-free gum or sugar-free hard candy will help keep your mouth moist without promoting tooth decay. Tart liquids and foods, such as lemonade or dill pickles, may help stimulate the flow of saliva. There are also saliva substitutes that you can buy at a drug store.
  • For hair loss. If you need high doses of
    radioactive iodine treatment, you may have some hair loss, but it is usually
    very mild. And you may be the only one who notices it.

Handling the stress of having cancer

Having cancer can be very stressful, and it may feel overwhelming to face the challenges in front of you. Finding new ways of coping with the symptoms of stress may improve your overall quality of life. These ideas may help:

  • Get the support you need. Spend time with people who care about you, and let them help you.
  • Take good care of yourself. Get plenty of rest, and eat nourishing foods.
  • Talk about your feelings. Find a support group where you can share your experience.
  • Stay positive. Do things each day that will help you stay calm and relaxed.

Having cancer can change your life in many ways. For support in managing these changes, see the topic

Getting Support When You Have Cancer.

Medications

Although
thyroid cancer is generally treated with surgery,
medicines may also be needed to treat the cancer and to replace thyroid
hormones.

Medicine choices

Medicines to treat thyroid cancer include:

  • Radioactive iodine, which is used after
    surgery to destroy any remaining thyroid tissue.
  • TSH suppression therapy to reduce the TSH in your body. This slows the growth of any
    remaining cancer cells.
  • Thyroid hormone medicine to replace necessary thyroid
    hormones that are made by your thyroid gland. If your thyroid gland is
    surgically removed, you will likely need to take thyroid replacement pills for the rest of your life.
  • Chemotherapy, which sometimes is used to treat
    thyroid cancer that has come back after surgery and to treat
    anaplastic thyroid cancer that does not respond to
    radioactive iodine.
  • Targeted therapy with tyrosine kinase inhibitors (TKIs), such as sorafenib and sunitinib. Targeted therapy with TKIs is being studied in clinical trials.

After you have your thyroid
surgically removed, you may have to wait several weeks before you have
radioactive iodine treatment to destroy any remaining thyroid tissue. During
the waiting period, you may have symptoms of hypothyroidism such as fatigue,
weakness, weight gain, depression, memory problems, or constipation.

Your
doctor may also put you on a low-iodine diet before treating you with radioactive iodine. If you are
on a low-iodine diet, you cannot eat foods that contain a lot of iodine, such
as iodized salt, seafood, and baked goods. Depleting your body of iodine may make radioactive
iodine treatment more effective, because your cells become "hungry" for
iodine.

After surgery, you may need to take thyroid hormone replacement pills for the rest of your life. Taking these pills rarely causes side effects if you are taking the right amount. But too much thyroid hormone can cause you to feel hot and sweaty. It can also cause weight loss, a fast heart rate, chest pain, cramps, or diarrhea. And too little thyroid hormone can cause you to feel cold and tired. It can also cause weight gain, dry skin, or dry hair.footnote 1

Surgery

Most people with thyroid cancer have surgery to remove the cancer. You may have part or all of your thyroid removed.

The kind of surgery you have may depend on your age, the type of cancer you have, how much the cancer has spread, and your general health.

Surgery choices

  • Thyroid lobectomy removes only one part (lobe) of the thyroid
    gland. This surgery is an option if your cancer is small and is only in one
    lobe of your thyroid gland.
  • Near-total thyroidectomy removes all but a very small part of the thyroid gland. This is done in special cases with smaller tumors or if an experienced surgeon is not available.
  • Total thyroidectomy removes
    the entire thyroid gland. This is the most common type of surgery. It provides the highest rates of cure and also makes radioactive iodine
    treatment and thyroid hormone therapy work better.

During surgery, lymph nodes in the neck may also be
removed and tested for cancer cells (lymphadenectomy). If thyroid cancer has spread to the lymph
nodes,
radioactive iodine will be used to destroy the
remaining cancer cells.

Most thyroid cancers grow and
spread so slowly that you can delay surgery for a short time if you need to. If
you choose to postpone surgery, your thyroid cancer should be watched closely
by an
endocrinologist.

Surgery to remove only
the part of the thyroid gland that contains cancer (lobectomy) is less
complicated than total thyroidectomy and less likely to lead to hypothyroidism.
But thyroid cancer comes back (recurs) after lobectomy more often than it does
after total thyroidectomy.

If you and your doctor decide that you need surgery, it is important to have the procedure done by a highly skilled surgeon at a hospital that has a good success rate. There are fewer problems from surgery when a person has a skilled and experienced surgeon.footnote 2

Other Treatment

Radiation treatment

Radiation treatment uses high-energy X-rays to kill cancer cells and shrink tumors. It is rarely used for thyroid cancer.

Low-iodine diet

  • Foods to avoid for a low-iodine diet
    include milk and other dairy products, commercial baked products (including
    most breads), seafood, and red food dye #3. A low-iodine diet is not the same
    as a low-salt diet. Most salt in the United States and Canada has iodine added,
    so low-iodine diets avoid iodized salt, but non-iodized salt is okay to eat.
  • For more information, talk to your doctor or a registered
    dietitian, or visit the Thyroid Cancer Survivor's Association website at
    www.thyca.org/rai.htm.

Complementary therapy

People sometimes use complementary therapies
along with medical treatment to help relieve symptoms and side effects of
cancer treatments. Some of the complementary therapies that may be helpful
include:

These mind-body treatments may help you feel better. They can make it easier to cope with treatment. They also may reduce chronic low back pain, joint pain, headaches, and pain from treatments.

Before you try a complementary therapy, talk to your doctor about the possible value and potential side effects. Let your doctor know if you are already using any such therapies. They are not meant to take the place of standard medical treatment.

Other Places To Get Help

Organizations

American Cancer Society (ACS)
250 Williams Street NWAtlanta, GA 30303
www.cancer.org

National Cancer Institute (U.S.)
www.cancer.gov (or https://livehelp.cancer.gov/app/chat/chat_launch for live help online)

References

Citations

  1. National Cancer Institute (2012). What You Need to Know About Thyroid Cancer. Available online: http://www.cancer.gov/cancertopics/wyntk/thyroid.
  2. National Comprehensive Cancer Network (2013). Thyroid carcinoma. NCCN Clinical Practice Guidelines in Oncology, version 1.2013. Available online: http://www.nccn.org/professionals/physician_gls/pdf/thyroid.pdf.

Other Works Consulted

  • American Cancer Society (2013). Cancer Facts and Figures 2013. Atlanta: American Cancer Society. Available online: http://www.cancer.org/Research/CancerFactsFigures/CancerFactsFigures/cancer-facts-figures-2013.
  • American Thyroid Association Guidelines Taskforce (2009). Revised American Thyroid Association management guidelines for patients with thyroid nodules and differentiated thyroid cancer. Thyroid, 19(11): 1167–1214. Also available online: http://thyroidguidelines.net/revised/taskforce.
  • Cooper DS, et al. (2007). The thyroid gland. In DG Gardner, D Shoback, eds., Greenspan's Basic and Clinical Endocrinology, 8th ed., pp. 209–280. New York: McGraw-Hill.
  • Davidge-Pitts CJ, Thompson GB (2015). Thyroid tumors. In VT DeVita Jr et al., eds., DeVita, Hellman, and Rosenberg's Cancer Principles and Practices of Oncology, 10th ed., pp. 1175–1188. Philadelphia: Walters Kluwer.
  • National Cancer Institute (2013). Thyroid Cancer Treatment (PDQ)—Health Professional Version. Available online: http://www.cancer.gov/cancertopics/pdq/treatment/thyroid/HealthProfessional.
  • National Cancer Institute (2013). Thyroid Cancer Treatment (PDQ)—Patient Version. Available online: http://www.cancer.gov/cancertopics/pdq/treatment/thyroid/Patient.
  • U.S. Preventive Services Task Force (2017). Screening for thyroid cancer: U.S. Preventive Services Task Force recommendation statement. JAMA, 317(18): 1882–1887. DOI:10.1001/jama.2017.4011. Accessed May 10, 2017.

Credits

ByHealthwise StaffPrimary Medical Reviewer E. Gregory Thompson, MD - Internal Medicine Kathleen Romito, MD - Family Medicine Adam Husney, MD - Family Medicine Specialist Medical Reviewer Matthew I. Kim, MD - Endocrinology

Current as ofDecember 1, 2017

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