Thyroid cancer begins in the thyroid at the base of the neck, but it can spread (metastasize) to other parts of the body. This includes the lungs.

Thyroid cancer begins in the thyroid gland, a butterfly-shaped organ located at the base of the neck.

The National Cancer Institute estimates that in 2023, more than 43,000 people will receive a thyroid cancer diagnosis in the United States. That’s 2.2% of all new cancer cases in the country.

Thyroid cancer is around three times more common in females and mostly affects white people.

While it starts in the thyroid, as the cancer advances, it can spread, or metastasize, from the thyroid to other parts of the body, including the lungs. Even if it’s detected in the lungs, it still has thyroid cancer features, so it’s still called thyroid cancer.

Here, we explore the causes, symptoms, diagnosis, treatment, and prognosis of thyroid cancer that has spread to the lungs.

Thyroid cancer can spread to other organs if it reaches the metastatic stage. When cancer spreads into other organs, it’s called distant metastasis.

Depending on the type of thyroid cancer, lung metastases can be more or less frequent. For example, the lungs are the most frequent location of metastases of papillary and follicular thyroid cancers.

Thyroid cancer that has spread into the lungs can have the following symptoms:

These symptoms usually appear in addition to symptoms of primary (original) thyroid cancer, such as:

To diagnose thyroid cancer in the lungs, a doctor begins with a physical exam. They may ask you about a history of cancer in you and your family. They may also order tests, including:

Which treatment a doctor prescribes for thyroid cancer that has spread into the lungs depends on the following:

  • type of thyroid cancer
  • your age and overall health
  • number, location, and size of metastases

Several therapies can help treat thyroid cancer and its metastases, such as:

Thyroid gland removal followed by radioactive iodine therapy is the most common way to treat thyroid cancer that has spread into the lungs.

Although people with thyroid cancer usually have a very good prognosis (outlook), distant metastasis, such as metastasis in the lungs, may significantly affect the chances of survival.

According to a 2014 study, the average 5-year survival of people with thyroid cancer metastases in one organ was around 77%. Those with metastases in more than one organ had a 15% chance of survival in the same time frame.

However, people treated for thyroid cancer today may have a better outlook because of improvements in treatment.

It’s important to remember that your outlook depends on multiple factors, such as:

  • type of cancer
  • your age and overall health
  • stage at diagnosis
  • type of treatment

Your endocrinologist and oncologist can give you a better idea of your individual outlook.

Thyroid cancer that has spread into the lungs is different from lung cancer. It’s an advanced stage of thyroid cancer that requires prompt diagnosis and treatment.

Symptoms of this condition usually occur with other symptoms of thyroid cancer, such as a lump on the neck and trouble breathing.

The most common treatment for thyroid cancer that has spread into the lungs is thyroid removal followed by radioactive iodine treatment.

Although thyroid cancer typically has a very good outlook, metastases can significantly affect your outcome. However, treatment options have improved over the last decade. Be sure to speak with your doctor about your individual prognosis.