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Differentiated Thyroid Cancer

What are differentiated thyroid cancers?

Differentiated thyroid cancers (DTCs) are a type of thyroid cancer. The thyroid gland lies just below the throat in the front of the neck. The thyroid makes hormones that control body functions.
DTCs are the most common type of thyroid cancer in children.

There are 2 types of DTCs:

  • Papillary thyroid cancer
  • Follicular thyroid cancer

About 90% of thyroid cancer cases in children are papillary thyroid cancer.
 

Graphic of an adult female body with layover of organs visible and the thyroid gland is highlighted and labeled.

The thyroid gland lies at the base of the throat in the front of the neck. It has 2 lobes, 1 on the right and the other on the left. The thyroid gland has follicular cells that make hormones. Small parathyroid glands lie behind the thyroid.

Papillary thyroid cancer often appears as nodules in the thyroid gland. The nodules may be in one or both lobes. By the time of diagnosis, this cancer has often spread outside of the thyroid to nearby lymph nodes in the neck.

Follicular thyroid cancer starts in the follicular cells of the thyroid gland. This cancer usually stays in the neck area, but it can sometimes spread to the lungs and bones.

The thyroid gland uses iodine from the diet to make hormones. DTCs take up iodine. This feature is important for screening and treatment with radioactive iodine.

Despite the tendency for DTC to spread in children, this type of cancer has an excellent outcome with a greater than 95% survival rate.

Surgery to remove the cancer is the main treatment. Patients with intermediate and high-risk DTC may receive treatment with 131I radioactive iodine (RAI).

Symptoms of differentiated thyroid cancer

Signs and symptoms of DTC include:

  • A lump (nodule) in the thyroid gland
  • Swollen lymph nodes in the neck
  • Breathing problems
  • Problems swallowing or pain when swallowing
  • Hoarseness

Thyroid cancer does not always cause symptoms. The doctor may find it during a regular physical exam.
 

Risk factors for differentiated thyroid cancer

DTC occurs most often in older children and teens. Teens are 10 times more likely to develop thyroid cancer than younger children. These cancers are more common in females than males.

Gene changes and risk for thyroid cancer

Families may have genetic disorders that increase their cancer risk. Parents may pass down these conditions to their children. Changes in the child's genes may also increase their cancer risk.

Patients with DTC often have a change (mutation) in the RET gene, so it does not work properly. A child may inherit this mutation from either parent. Or your child may be the first person in your family with this gene change.

Your child's care team may suggest genetic counseling and genetic testing if your child has one of these gene changes.

Genetic syndromes (disorders) linked to DTCs include:

  • Familial adenomatous polyposis (FAP)
  • PTEN hamartoma tumor syndrome
  • DICER1 syndrome
  • Carney complex

Ionizing radiation and risk for thyroid cancer

Exposure to high doses of radiation can increase a person's risk for cancer. There is a higher risk of cancer from ionizing radiation when:

  • Patients receive radiation as a medical therapy
  • The radiation treatment includes higher doses of radiation at a younger age
  • There is environmental exposure to large amounts of radiation

Learn more about radiation safety.
 

Diagnosis of differentiated thyroid cancer

Doctors use several types of tests to diagnose medullary thyroid cancer. Tests may include:

  • Physical exam and health history, including a family health history, to check for inherited cancer risk and other risk factors
  • Lab tests
    • Blood tests for hormones that show how well the thyroid is working, such as thyroid stimulating hormone (TSH), T3, and free T4 (thyroxine)
    • Blood tests to look for tumor markers, including proteins such as thyroglobulin (Tg). These tests can help detect if any thyroid cancer remains after surgery or if it comes back.
    • Genetic tests to find changes in genes (mutations) that may increase the risk for cancer
  • Imaging tests to find tumors, measure their size, and see if cancer has spread. Doctors use these details to plan the next steps for diagnosis and treatment.
  • Biopsy of a sample from the tumor to see if there are cancer cells. A fine needle aspiration (FNA) allows doctors to take a thyroid tissue sample using a thin needle inserted through the skin.

Stage of differentiated thyroid cancer

The cancer stage depends on the nodule's features and if cancer has spread to other parts of the body. The stages are:

  • Stage 1: There is no cancer found outside the neck.
  • Stage 2: Cancer has spread outside the neck to distant sites.

The stage helps doctors classify patients into risk groups after surgery. In general, children with DTC have a good prognosis. However, some patients are at higher risk for more disease.

Risk group Spread of disease
Low Risk Cancer is only in the thyroid gland with little or no spread to lymph nodes.
Intermediate Risk Some cancer has spread to nearby lymph nodes.
High Risk Cancer has spread to nearby lymph nodes, tissues outside the thyroid, or other parts of the body such as the lungs.

Treatment of differentiated thyroid cancer

A team of specialists will evaluate, treat, and monitor your child's cancer. The team will balance the need for care and treatment with possible harm from treatment side effects. The team will monitor your child because:

  • Their cancer may return
  • They may have problems with hormone functions
  • There could be inherited risks
     

  1. Surgery to remove the thyroid

    Before surgery, the care team will do an ultrasound and a fine needle aspiration on any lymph nodes that may have cancer. This helps the doctor plan the surgery.

    Surgery to remove the thyroid gland (thyroidectomy) is the main treatment for thyroid cancer. This surgery:

    • Lowers the risk of more thyroid cancer
    • Helps with follow-up care using radioactive iodine for imaging and treatment

    If the tumor is small, the surgeon may do a partial thyroidectomy. This procedure only removes 1 lobe and the isthmus of the thyroid gland.

    Your child's doctor may also remove lymph nodes and other tissues in the center or sides of the neck. This procedure is known as a neck dissection. The surgeon may remove lymph nodes that interact with the thyroid gland and may have cancer cells. High-risk patients may need more surgery to stop cancer from returning.

    Risks of thyroid surgery

    During thyroid surgery, there is a risk of damage to neck structures and parathyroid glands.

    Hypoparathyroidism

    The parathyroid glands are 4 small glands that lie behind the thyroid. These glands release parathyroid hormone. This hormone keeps calcium levels at a normal level in the body.

    Sometimes, there is harm to the parathyroid glands during surgery. The parathyroid glands may become "stunned” even if they are not damaged. This results in hypoparathyroidism and low levels of parathyroid hormone.

    Symptoms include:

    • Low levels of calcium in the blood (hypocalcemia)
    • Numbness and tingling in the hands, feet, and face
    • Muscle cramps

    Doctors treat this condition with vitamin D (calcitriol) and calcium supplements until these problems stop. Hypothyroidism may be temporary or permanent.

    Nerve or vocal cord problems

    Another risk of thyroid surgery is nerve damage to the recurrent laryngeal nerve (RLN). This nerve helps the vocal cords move for speech. Nerve problems after thyroid removal are rare.

    A specialist will do a "scope" procedure to check the vocal cords before and after surgery. The doctor will gently place a small, flexible camera into your child's nose to see the vocal cords and check their function.

    Vocal cord injuries during surgery are often temporary. But some patients may need a longer recovery time, even a year or longer.

    Patients may need more treatment if their voice changes or they have problems breathing or swallowing. The doctor can inject temporary material into the vocal cords to help them work better. Sometimes, the patient may need surgery to improve vocal cord function.
     

  2. Postoperative staging and risk-based treatment

    After surgery, your child will have tests to plan follow-up care and monitoring. Your child may need other treatments, such as radioactive iodine (131I) therapy or more surgery.

    After surgery, the doctor monitors low-risk patients with regular screening. They may receive a medication called levothyroxine (or T4). This medicine blocks thyroid stimulating hormone (TSH), known as TSH suppression. TSH suppression keeps TSH hormone levels low, which can help stop tumor cell growth.

    Monitoring includes:

    • Blood tests for thyroglobulin (Tg) protein
    • Tests for thyroglobulin antibody levels
    • Ultrasound imaging to find any cancer

    Some intermediate-risk and all high-risk patients receive TSH-stimulated thyroglobulin and a diagnostic whole-body scan. This scan looks for the spread of thyroid cancer to other parts of the body.

    For this test:

    • The care team gives the patient a radioactive tracer, usually radioiodine (RAI) I-123. This level of radiation is quite low.
    • Thyroid cells normally use iodine to make hormones. Thyroid cancer cells do the same, so they take up the tracer.
    • The radiologist takes pictures using a special camera that can see the tracer. The pictures show the location of cancer in the body.

    Based on the results and thyroglobulin levels, the doctor may treat the patient with radioactive iodine to kill the cancer cells. The patient may have more surgery if it is possible to remove the cancer.

  3. Radioactive iodine treatment

    Patients with intermediate and high-risk DTC may receive 131I radioactive iodine (RAI) treatment.

    In this therapy, the care team stimulates thyroid cells and thyroid cancer cells so that the cells take up radioactive iodine. The radiation from the iodine goes directly to the thyroid cells and kills them. It also kills cancer cells that spread to other parts of the body.

    But unlike the low-dose 123I used for imaging tests, the higher doses of 131I RAI for treatment may cause side effects and increase the risk for late effects.

    Some studies suggested that 131I RAI therapy may slightly increase the risk of second cancers. But researchers have not studied this therapy enough yet in children and teens. The medical team and family must consider the thyroid cancer risks, the benefits of treatment, and the child's needs.

    Low iodine diet

    Your child must stay on a low-iodine diet for 7 days before receiving 123I or 131I. Below are resources for the low-iodine diet:

     

  4. Targeted therapies

    Doctors are studying targeted therapies to treat thyroid cancers. These medicines work on certain features of cancer cells.

    Patients with advanced disease or disease that comes back may consider enrolling in a clinical trial.

Prognosis for differentiated thyroid cancer

DTC has a greater than 95% survival rate in pediatric patients.

Recurrence is more likely in children under 10 years of age and patients whose cancer has spread to the lymph nodes before diagnosis. Even with the risk of recurrence, their chance of survival is good.

Factors that influence prognosis include:

  • How much initial surgery the patient needed
  • Whether cancer has spread to other places, such as the lungs or bones
  • Gene mutations or genetic syndromes that increase the risk of other cancers

Your child's doctor is the best source of information about your child's case.

Support for patients with differentiated thyroid cancer

After treatment, your child will need lifelong monitoring and follow-up care from a team of specialists. This care is important because:

  • There is a risk that cancer could come back (recurrence)
  • Hormone function is affected
  • Gene changes may increase the risk for other health problems or cancers

Monitoring for recurrence and follow-up care

The care team will recommend the frequency and type of tests for monitoring, which depends on individual patient needs.

Follow-up care may include:

  • Regular physical exams to check thyroid and lymph nodes
  • Ultrasound imaging of the neck and thyroid
  • TSH suppression and hormone replacement therapy (levothyroxine) after surgery
  • Monitoring blood thyroglobulin (Tg) and Tg antibodies

Recurrence of thyroid cancer can happen many years after treatment. Regular monitoring provides early detection of thyroid cancer that develops later.

Psychosocial care after thyroid and neck surgery

Care team members with Psychology, Child Life, Social Work, and other areas can help your child cope and improve their quality of life. They can assist with concerns, including:

  • Problems taking medicines daily
  • Body image concerns due to surgical scars
  • Physical therapy after surgery to assist with neck mobility and range of motion.
  • Worry about genetic conditions and future risks for cancer
  • How their diagnosis might affect future children

Adjusting to a thyroid cancer diagnosis can be challenging for families. Although the prognosis is generally good, the disease requires lifelong management with medication and monitoring. Your child may need more support as they go from adolescence to young adulthood and gain independence. Adjustment challenges may also be greater for patients who have thyroid cancer as second cancer.

Late effects of therapy

Doctors recommend that patients receiving radioactive iodine therapy be followed for possible long-term and late effects of treatment. These can include:

  • Follow-up care for problems with salivary glands and greater risk of tooth decay with dry mouth
  • Monitoring for effects on reproductive organs and fertility
  • Monitoring lung function in patients where the disease affected the lungs
  • Monitoring for more cancer that happens later (second primary cancer)

Health after cancer

All cancer survivors should live a healthy lifestyle and get regular physical checkups and screenings by a health care provider familiar with cancer survivorship issues to stay well.

Your care team may prepare a survivorship care plan. This plan is a complete record of your child's treatment, medical concerns, and health screenings they need.

Questions to ask your care team

  • What is the type and stage of cancer?
  • Is this cancer related to any genetic condition?
  • Does my child or family need genetic tests and genetic counseling?
  • What are my child's treatment options?
  • What are the possible side effects of these treatments?
  • If my child needs surgery, does the surgeon perform these surgeries often for pediatric patients with this cancer?
  • Will my child need to stay in the hospital for treatment?
  • What tests does my child need for long-term monitoring and follow-up?
  • What late effects could happen after treatment?

Key points about differentiated thyroid cancer

  • Differentiated thyroid cancers (DTCs) are the most common type of thyroid cancer in children.
  • The two kinds of DTCs are papillary thyroid cancer and follicular thyroid cancer.
  • Doctors may order lab testing, imaging studies, and a tumor biopsy to diagnose this cancer.
  • Treatments may include removal of the thyroid gland (thyroidectomy), radioactive iodine treatment, or targeted therapies.
  • For most children with DTC, the prognosis is good even if the disease has spread or come back after treatment.
  • After treatment, patients need lifelong monitoring and follow-up care.
Emma and her friend Margaret in hospital room

Finding Support Through Friendship

Friendship helped patient Emma Gilpen navigate thyroid cancer treatment.

Learn more.

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Together does not endorse any organization mentioned in this article. 

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Reviewed: December 2022

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Medullary Thyroid Cancer

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