Thyroid Cancer: Anaplastic Cancer

This page includes more advanced information on a specific type of thyroid cancer—anaplastic thyroid cancer. Please read our Introduction to Thyroid Cancer article first, which gives a general overview of all types of thyroid cancer. Doing so will make this page easier to understand.

Anaplastic tumors are the least common (about 0.5% to 1.5% of people with thyroid cancer have this type) and most deadly of all thyroid cancers. This cancer has a very low cure rate with the very best treatments. Only 10% of patients are alive 3 years after it is diagnosed. Most patients with anaplastic thyroid cancer do not live one year from the day they are diagnosed.

Anaplastic thyroid cancer often arises within a more differentiated thyroid cancer or even within a goiter. Like papillary cancer, anaplastic thyroid cancer may arise many years (>20) following radiation exposure. Cervical metastasis (the spread of the cancer to lymph nodes in the neck) are present in the vast majority (over 90%) of cases at the time of diagnosis. The presence of lymph node metastasis in these cervical areas causes a higher recurrence rate and is predictive of a high mortality rate.

The most common way this cancer becomes evident is by the patient or his or her family member noticing a growing neck mass. When the doctor feels the neck mass, it is usually large and very hard. These tumors grow very rapidly, and the patient will likely state that he or she never noticed it until a few days or weeks ago, and now it seems to get bigger every few days.

Anaplastic cancers invade adjacent structures and metastasize extensively to cervical lymph nodes and distant organs, such as the lungs and bones. Tracheal invasion is present in 25% at the time of presentation (said differently, in about 25% of cases, the anaplastic cancer has grown out of the thyroid and into the trachea). This is why many patients with anaplastic thyroid cancer will need a tracheostomy, while almost nobody with the other types of thyroid cancer will need one.

Spread to the lungs is present in 50% of patients at the time of diagnosis. Most of these cancers are so aggressively attached to vital neck structures that they are inoperable at the time of diagnosis (the surgeon can't remove it because it's growing into other neck structures). Even with aggressive therapy protocols, such as hyperfractionated radiation therapy, chemotherapy, and surgery, survival at 3 years is less than 10%.

Characteristics of Anaplastic Thyroid Cancer

• Peak onset age is 65 and older.
• It's very rare in young patients.
• It's more common in males than females by 2 to 1 ratio.
• It typically presents as rapidly growing neck mass.
• It can occur many years after radiation exposure.
• The spread to lymph nodes of the neck is present in more than 90% of cases.
• The distant spread (to lungs or bones) is very common even when it's first diagnosed.
• The overall cure rate is very low.
• It typically requires a very aggressive treatment plan with surgery, radiation, and sometimes even chemotherapy.
• It often requires a tracheostomy to maintain the patient's airway.

Management of Anaplastic Thyroid Cancer

The major problem with anaplastic thyroid cancer is that it is usually too aggressive and invasive when it is diagnosed. Therefore, only a small portion of patients can undergo surgical re-section of the cancer in hopes of curing it. For those patients who are diagnosed at an earlier stage, a total thyroidectomy is necessary. Many patients, especially those who have advanced cancer and cannot undergo surgical resection, will benefit from external-beam radiation (this is different from radioactive iodine). Some chemotherapy treatments may also be beneficial to patients with anaplastic thyroid cancer.

CASE STUDY: October 2004 through September 3, 2005

In October 2004, 3 weeks after his 80th birthday, Chief Justice William Rehnquist was diagnosed with anaplastic thyroid cancer. It was not announced for a number of weeks what type of thyroid cancer he had—only that he had thyroid cancer. 

But if we look at our list above, we can see that his case is classic for anaplastic thyroid cancer. He received some of the best medical care in the world, including annual physical exams. The mass in his neck was rapidly growing and obviously was not present a year earlier—this is very typical of anaplastic thyroid cancer. He was in the correct age group for anaplastic cancer.

The very day of his diagnosis, he underwent a tracheostomy, a procedure that is typical of patients with anaplastic thyroid cancer and extremely rare for the other types of thyroid cancer. He immediately began external-beam radiation therapy (again, classic for anaplastic thyroid cancer and almost never used for the typical papillary or follicular thyroid cancers). He also began chemotherapy treatments, which are essentially never used for papillary, follicular, and hurthle cell thyroid cancers.

On Thursday, January 20, 2005, Chief Justice Rehnquist swore in George W. Bush as President of the United States for his second term. The Chief Justice appeared to be doing very well, but he had a tough road in front of him.

On Saturday, September 3, 2005, Chief Justice Rehnquist died in his home at the age of 80. Sadly, his case is typical of anaplastic thyroid cancer. He died of a disease that was diagnosed less than 11 months earlier. Not all people with anaplastic cancer die, but it is extremely important that this disease is caught early and treated aggressively.