Anaplastic Thyroid Cancer (ATC)

Anaplastic thyroid cancer (ATC) is a rare and very aggressive form of thyroid cancer. It grows quickly and often spreads (metastasizes) to other areas of your body. While the prognosis is often poor, some people with ATC have lived for several years after treatment.


What is anaplastic thyroid cancer (ATC)?

Anaplastic thyroid cancer (ATC) is a rare and very aggressive form of thyroid cancer.

Your thyroid is a small, butterfly-shaped gland located at the front of your neck under your skin. It’s a part of your endocrine system and controls many of your body’s important functions by producing and releasing (secreting) certain hormones.

ATC is also known as undifferentiated thyroid cancer because the cells don’t look or behave like typical thyroid cells.

Due to the extremely aggressive behavior of ATC, the American Joint Committee on Cancer (AJCC) defines all of its stages as stage IV.


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Who does anaplastic thyroid cancer affect?

Most cases of anaplastic thyroid cancer (ATC) are diagnosed in people over 60 years old. People assigned female at birth are more likely to be affected by ATC than people assigned male at birth.

How common is anaplastic thyroid cancer?

Anaplastic thyroid cancer is rare. It consists of about 2% of all thyroid cancer cases. About 1 to 2 people per million are diagnosed in the United States every year.


How quickly does anaplastic thyroid cancer develop?

Anaplastic thyroid cancer is one of the most aggressive and fastest-growing types of cancer. It can grow and spread rapidly in a matter of weeks.

About 50% of people with ATC have metastasis (cancer spread) in distant areas of their body at diagnosis. The most common sites of distant metastasis in ATC are your lungs, bones and brain.

Symptoms and Causes

What are the symptoms of anaplastic thyroid cancer?

Anaplastic thyroid cancer most often presents as a lump or nodule on your thyroid in the front of your neck.

ATC tumors grow very quickly and are often visible to the person with ATC or their family and friends. The tumor is typically painful and firm.

If the tumor grows large enough, it can compress other structures in your neck and cause the following symptoms:

People with anaplastic thyroid cancer that has spread (metastasized) may also have the following symptoms:


What causes anaplastic thyroid cancer?

Scientists still don’t know the exact cause of anaplastic thyroid cancer (ATC). In some cases, however, it occurs in the setting of differentiated thyroid cancers, such as papillary or follicular thyroid cancers.

Up to 80% of ATC cases occur in the setting of a long-standing goiter (enlarged thyroid), possibly in the background of undiagnosed differentiated thyroid cancer.

Diagnosis and Tests

How is anaplastic thyroid cancer diagnosed?

Healthcare providers typically perform a fine needle aspiration (needle biopsy) to diagnose anaplastic thyroid cancer (ATC). During this procedure, your provider takes a small tissue sample, called a biopsy, from the mass on your thyroid using a very thin needle. A pathologist will look at the tissue under a microscope to see if there are cancer cells and, if so, what type of thyroid cancer it is.

In some cases, your provider may recommend a core biopsy (a biopsy obtained using a larger needle).

Once your healthcare team has confirmed the diagnosis of ATC, they’ll recommend tests to get a full assessment of your overall health to determine if and where the cancer has spread. This may include blood tests and imaging tests, such as:

All people with anaplastic thyroid cancer are diagnosed as stage IV due to the aggressive nature of this tumor. There are three sub-stages, including:

  • Stage IVA: ATC is present only in your thyroid. This is the case in about 10% of diagnoses.
  • Stage IVB: ATC is present in your thyroid and your neck (typically your lymph nodes), but not in other parts of your body. This is the case in about 40% of diagnoses.
  • Stage IVC: ATC is present in your thyroid as well as other parts of your body, such as your bones, lungs or brain. This is the case in about 50% of diagnoses.

Management and Treatment

How is anaplastic thyroid cancer treated?

Anaplastic thyroid cancer (ATC) is difficult to treat because it’s very aggressive and can spread quickly within your neck and to distant parts of your body, such as your lungs, bones and brain.

Because of this, it’s important to start treatment as soon as possible and to work with healthcare providers who are experienced in treating ATC. Treatment of ATC often involves a multidisciplinary team of specialists, including:

Treatment for ATC typically consists of a combination of the following:

Surgery for anaplastic thyroid cancer

If you have ATC, your healthcare team will likely recommend surgery to remove the tumor unless you have other medical conditions that would make surgery too risky.

Debulking surgery is the most common procedure in ATC treatment. It involves surgically removing as much of the tumor as possible, especially any part of the tumor that’s potentially threatening your airway, with the aim of preserving your larynx (voice box).

Unfortunately, in many cases, surgery isn’t possible due to the large size, location and invasiveness of the tumor.

It’s important to know that there are some cases of people with ATC who lived several years after treatment who weren’t able to have surgery but did have an aggressive combination of radiation and chemotherapy.

Radiation therapy for anaplastic thyroid cancer

Radiation therapy is a form of cancer treatment that uses radiation (strong beams of energy) to kill cancer cells or keep them from growing and dividing.

If you have ATC, your healthcare team will likely recommend a certain type of radiation therapy called external beam radiation therapy (EBRT). This therapy directs precisely focused X-rays to areas that need to be treated — often the tumor itself or cancer that has spread to bones or other organs.

Chemotherapy for anaplastic thyroid cancer

Chemotherapy is a type of cancer treatment that works by destroying cancer cells and preventing them from multiplying.

If you have ATC, your healthcare team may recommend chemotherapy as adjuvant therapy. This means that chemotherapy destroys cancer cells after surgery or radiation therapy. More specifically, chemotherapy for ATC enhances the radiation therapy to make the cancer more susceptible to the radiation or make the radiation more effective.

New chemotherapy drugs that have shown promise in treating other advanced cancers are becoming more widely available for advanced thyroid cancer treatment. These drugs rarely cure advanced cancers that have spread widely throughout your body, but they can slow down or partially reverse the growth of cancer.

Chemotherapy drugs used for thyroid cancer include:

Palliative care for anaplastic thyroid cancer

Palliative care is medical care that relieves pain, symptoms and stress caused by serious illnesses.

If you have ATC, your healthcare team may recommend palliative care to manage symptoms of ATC and the side effects of the treatment.

Palliative care for ATC may include:

  • Placing a tube in your throat to help with breathing (tracheostomy).
  • Placing a feeding tube in your stomach (gastrostomy tube or G-tube).
  • Providing pain medication.

Providers offer palliative care in addition to treating cancer. Palliative care doesn’t necessarily mean the cancer treatment won’t be effective.

Can anaplastic thyroid cancer be cured?

Anaplastic thyroid cancer can’t be cured by surgery, unlike some cases in other types of thyroid cancer. Complete removal of the thyroid gland (thyroidectomy) doesn’t prolong the lives of people who have ATC.


Can anaplastic thyroid cancer be prevented?

Unfortunately, in most cases, anaplastic thyroid cancer (ATC) can’t be prevented.

If you’ve been diagnosed with goiter or a benign (noncancerous) thyroid nodule, it’s important to see your healthcare provider regularly to monitor the health of your thyroid. ATC can sometimes develop from other types of thyroid cancer and/or goiter.

Outlook / Prognosis

What can I expect if I have anaplastic thyroid cancer?

Just as each person is unique, each case of anaplastic thyroid cancer (ATC) presents differently and responds to treatment differently. ATC is characteristically difficult to predict.

Scientists are making advancements every day in the treatment of advanced thyroid cancers, including ATC. The treatment is challenging, but it’s important to not give up hope when you’re first diagnosed.

It’s important to work with a team of healthcare providers who have experience with anaplastic thyroid cancer. If you’re unable to travel to a major medical facility that has experience with ATC, don’t be afraid to ask your local providers to collaborate with experts at more experienced centers on your treatment plan.

Understanding the risks and benefits involved with various treatment options is essential. You must advocate for yourself and lean on family and friends for support.

What is the survival rate for anaplastic thyroid cancer?

The average survival rate of anaplastic thyroid cancer (ATC) is five to six months after diagnosis. Less than 20% of people with ATC are alive one year after diagnosis.

While these overall survival statistics are discouraging, it’s important to note that some people have lived for several years after anaplastic thyroid cancer treatment.

What is the prognosis (outlook) of anaplastic thyroid cancer?

Due to the aggressive nature of anaplastic thyroid cancer and the lack of effective treatment options, the prognosis is often poor.

Most people who have ATC die from airway obstruction from the tumor or complications of pulmonary metastases (cancer spread in your lungs) within one year.

People with ATC who have the following factors generally have a better prognosis:

  • Being younger than 60 years old.
  • Having a unilateral tumor.
  • Having a tumor size of less than 5 centimeters (cm).
  • Having no lymph node involvement or distant metastases.

Living With

How do I take care of myself if I have anaplastic thyroid cancer?

If you have anaplastic thyroid cancer, having a clear view of your prognosis may be the best way to take care of yourself. Ask your healthcare provider what you can expect, given your specific situation.

These aren’t easy conversations for you or your provider, but they’re important. Your provider can help you understand what’s happening to your body and what might happen. They can help you to think about your options and suggest helpful resources.

Should I consider hospice care if I have anaplastic thyroid cancer?

Hospice care helps people who have advanced, life-limiting illnesses to spend their final days comfortably, with dignity, control and quality of life.

When people are fighting a serious illness, their time and energy are often focused on their medical treatment. Thinking about hospice shifts the focus from illness to how they want to spend the time they have. Most people decide to enter hospice care after discussing the idea with their healthcare provider, family and other loved ones. If you’re considering hospice care, ask your provider for help finding information and resources.

A note from Cleveland Clinic

Receiving a cancer diagnosis is unsettling, regardless of the type. Given the poor prognosis of anaplastic thyroid cancer, it can be especially daunting. While treatment for ATC is challenging, it’s important to not give up hope when you’re first diagnosed. If you’re struggling with the idea of a possibly terminal illness, talk to your healthcare team. They’ll find resources to help you find your way.

Medically Reviewed

Last reviewed by a Cleveland Clinic medical professional on 07/25/2022.

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