Thyroid Cancer

1 What is Thyroid Cancer?

Thyroid cancer is a type of cancer that begins in the cells of the thyroid, the biggest gland in the neck, located just below your Adam's apple.

Thyroid hormones regulate your heart rate, blood pressure, body temperature and weight.

In most cases, thyroid cancer is curable with currently available treatments.

2 Symptoms

In its early stage, no signs or symptoms of thyroid cancer may be noticed. The symptoms start appearing as the disease advances, which include:

Visit your doctor if any signs or symptoms bother you. You may be recommended tests to confirm the diagnosis or determine the exact cause behind your symptoms.

3 Causes

The exact cause of thyroid cancer has not been identified yet. Like other cancers, thyroid cancer occurs due to changes in the DNA of the cells in the thyroid (genetic mutations).

Unlike normal cells, the mutated cells multiply and grow rapidly. This out-of-control growth of cells results in a formation of a tumor.

The cancer cells attack the surrounding tissues and may even travel to distant body organs (metastasis).

Knowing which type of thyroid cancer you have helps to choose appropriate treatment options and also determines the prognosis.

The types of thyroid cancer are: 

Papillary thyroid cancer: This is the most common type of thyroid cancer that is usually seen in people of ages 30-35.

Cancer begins in the cells that manufacture and store thyroid hormones, follicular cells.

Follicular thyroid cancer: Like papillary thyroid cancer, follicular cancer also begins in the follicular cells of the thyroid. It is usually seen in people above 50.

There is a more aggressive and rare type of follicular thyroid cancer, which is called Hurthle cell cancer.

Medullary thyroid cancer: Medullary thyroid cancer develops from the calcitonin-producing cells of the thyroid, called C cells.

As it involves the overgrowth of calcitonin-producing cells, elevated blood levels of calcitonin is obvious, which is also an early marker of this type of cancer.

Anaplastic thyroid cancer: It is a rare and rapidly advancing type of thyroid cancer that affects people above 60. The treatment is often less rewarding.

Thyroid lymphoma: Like anaplastic thyroid cancer, this type is also rare, advances rapidly and affects older adults. It occurs when the immune cells in the thyroid overgrow.

4 Making a Diagnosis

Making a diagnosis of thyroid cancer is done by performing several tests and procedures.

Visit your doctor if you experience any signs and symptoms that worry you. If suspected of having thyroid cancer, you may be referred to an endocrinologist (a specialist in endocrine disorders).

Getting prepared for the visit can optimize the therapy and help make the visit more fruitful.

List out all the symptoms. Write down your key medical information. Write down the names of all your medications, vitamins or supplements.
Ask a friend or family member to accompany you during the visit. Make a list of the questions to ask your doctor.

Some typical questions can be:

  • Do I have thyroid cancer? If so, which type?
  • What are my treatment options and side effects of each option?
  • Can I continue my daily life during the treatment?
  • Do I need to visit a specialist in thyroid diseases?
  • May I have some thoughts before going for a specific treatment option?

A clear talk with your doctor can optimize the therapy and improve the outcomes. Prepare yourself to answer some essential questions from your doctor.

Your doctor might ask you typical questions like:

  • When did your symptoms begin and how severe are they?
  • Are your symptoms occasional or continuous?
  • Does any factor improve or aggravate your symptoms?
  • Have you ever been exposed to radiation, may be during radiation therapy or a nuclear accident?
  • Do you have a family history of thyroid problems like goiter or other endocrine cancers?

Your doctor may recommend following tests and procedures for diagnosis:

  • Physical exam: Your doctor examines your thyroid to see if any physical change like a lump is present.
  • S/he can also talk to you to determine your risk of cancer such as exposure to radiation and a family history of thyroid tumors.
  • Blood tests: Blood tests check how well your thyroid is working.
  • Biopsy: Your doctor may remove a sample of cells from your thyroid and send it to the lab for analysis.
  • Under the guidance of ultrasound imaging, a long, thin needle is inserted into the lump in the thyroid.
  • Imaging tests: Imaging tests such as computerized tomography (CT) scans, positron emission tomography (PET) or ultrasound are used to determine if cancer has spread to other parts.
  • Genetic testing: Medullary thyroid cancer may have some genetic link that may be revealed during a genetic testing.

5 Treatment

The choice of treatment for thyroid cancer is determined by:

  • the type and stage of your cancer,
  • your general health status,
  • your preferences.

In most cases, treatment provides cure.

Some treatment options are:

  • Surgery: Surgery can be performed to remove entire or a portion of the thyroid. Operations have different approaches which can be:
    • Removing all or most of the thyroid (thyroidectomy or near-total thyroidectomy): Majority of the cases of thyroid cancer are treated by removing the entire thyroid. The surgery accesses your thyroid through an incision at the base of your neck.
    • Removing lymph nodes in the neck: During thyroidectomy, your surgeon can also remove lymph nodes from your neck and check if they contain cancer cells.
    • Removing a portion of the thyroid (thyroid lobectomy): In cases of small or early thyroid cancer, only one lobe of the thyroid may be removed.

Thyroid surgery may increase a risk of bleeding and infection. A thyroid surgery may cause damages to parathyroid glands which can result in low calcium levels in your body. During the surgery, if surrounding nerves are damaged, it may lead to vocal cord paralysis, hoarseness, soft voice or difficulty breathing.

  • Thyroid hormone therapy: After your thyroid is removed by surgery, you will need to take levothyroxine for life to replace the hormone that would be normally produced by your thyroid and to cut down the release of thyroid-stimulating hormone (TSH). TSH is a hormone produced by your pituitary gland, which causes the thyroid to release thyroid hormones. The dose of levothyroxine that you need is determined by regular blood tests.You may need the blood tests done every year. 
  • Radioactive Iodine: After your thyroid is removed by surgery, you will need to swallow capsule or liquid that contains radioactive iodine, to kill any thyroid cells that have survived the surgery. Sometimes, it can be used to treat a thyroid cancer that “returns” or “spreads”. Radioactive iodine, though safe, may cause side effects like: 
    • Nausea
    • Dryness in mouth and eyes
    • Altered sense of taste or smell
    • Pain in the regions where thyroid cancer has spread, such as the neck or chest

Most of the radioactive iodine is eliminated from your body via urine in the first few days after treatment. You have to exercise some precautions while taking this drug in order to limit the effects of radiation on people close to you. One simple measure could be to stay away from children and pregnant women.

  • External radiation therapy: In a procedure called external beam radiation therapy, you lie still on a table and a radiation-producing machine that moves around you hits your target organs with beams of radiation. Generally, the treatment lasts for a few minutes at a time, five days a week, for about five weeks. This therapy is an option if surgery is not an option for you and the cancer is unresponsive to radioactive iodine treatment. Sometimes, radiations may be used to retard the growth of cancer that has extended to the bones.
  • Chemotherapy: Chemotherapy drugs are given through your vein, from where they travel along with blood to reach distant body parts and kill cancer cells. Chemotherapy is not a regular treatment option for thyroid cancer, but may be recommended for people unresponsive to other therapies.
  • Alcohol ablation: Guided by ultrasound, your doctor injects alcohol directly into small thyroid cancers that aren't easily accessible during surgery. It may also be used for treating small recurrent thyroid cancer.
  • Targeted drug therapy: Targeted drugs like cabozantinib, sorafenib, vandetanib are used to attack specific abnormalities in your cancer cells. This approach is useful to treat advanced thyroid cancer.

6 Prevention

As the cause of thyroid cancer is not clear, doctors cannot do much to suggest your measures of prevention in the average-risk population.

However, you may follow these suggestions if you are at high risk:

  • Prophylactic thyroidectomy is recommended for adults and children with genetic predisposition to medullary thyroid cancer.
  • Talk to a genetic counselor to learn more about your risk of thyroid cancer and what treatment options you have.
  • People who live near a nuclear power plant are at increased risk of radiation and a nuclear fallout could cause thyroid and other cancer in them. If you live within 10 miles of a nuclear power plant in the United States, you may be given potassium iodide tablet, a medication may protect your thyroid from radiation.
  • In a case of emergency, you and your family could take the potassium iodide tablets to protect yourselves from radiation.
  • Contact your state or local emergency management department for more information.

7 Lifestyle and Coping

Lifestyle modifications are necessary in order to cope with thyroid cancer.

A diagnosis of cancer is a devastating experience and thyroid cancer is no different. You may feel as if your world has stopped and you are helpless.

As the time passes by, everyone finds his or her own way to handle the situation.

Until you find one, consider the following:

  • Learn more about your condition: You may refer to reliable sources like National Cancer Institute, the American Cancer Society, and the American Thyroid Association.
  • Gather as much information as possible through various reliable information sources.
  • Having an insight of what you are going through could lead to better outcomes in terms of treatments and lifestyle management.
  • Connect with other thyroid cancer survivors: Sharing your pain with people similar to you is a great idea to minimize your emotional baggage. Talk to your doctor about support groups in your area.
  • You may also find online support groups such as the American Cancer Society Cancer Survivors Network or the Thyroid Cancer Survivors' Association. 
  • Keep yourself as healthy as you can: Cancer is often out of your control but your health is definitely in your hands.
  • Eat a healthy diet full of a variety of fruits and vegetables. Sleep well. Get enough rest and include some sort of physical activity into your daily routine.

8 Risks and Complications

There are several risks and complications associated with thyroid cancer. Risks include:

  • Sex: Thyroid cancer is more common in women.
  • Exposure to high levels of radiation: People who are exposed to high levels of radiation during radiation therapy or from nuclear fallout after a nuclear accident have a higher risk of developing thyroid cancer.
  • Certain inherited genetic syndromes: Genetic syndromes that increase the risk of thyroid cancer are familial medullary thyroid cancer, multiple endocrine neoplasia, and familial adenomatous polyposis.

Thyroid cancer is often resistant and may come back even after treatments including the one that removes your thyroid.

It might be due to microscopic cancer cells that have spread beyond the thyroid.

Recurrence is most common during the first five years after surgery, but cases of recurrence decades after initial thyroid cancer treatment have been reported.

Recurrence is common in:

  • Lymph nodes in the neck
  • Small pieces of thyroid tissue left behind during surgery
  • Other areas of the body

Recurrent thyroid cancer is a treatable condition and you may need periodic blood tests or thyroid scans to detect signs of recurrence.

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