Thyroid Cancer: Everything You Need to Know About the Disease

Learn the signs and symptoms to look out for.

By Michael Crupain, MD, MPH
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Insight Into Your Thyroid (3:00)

Thyroid cancer isn’t the most common cancer, but it’s vitally important you’re aware of the signs and symptoms.

According to the American Cancer Society, an estimated 52,070 new cases of thyroid cancer will be diagnosed in 2019. For comparison, over 250,000 individuals will be diagnosed with breast cancer in 2019. Thyroid cancer disproportionately impacts women. They’re nearly three times more likely to develop the disease than men. Here’s what you – and your doctor – should look for. 

What is a thyroid nodule?

A thyroid nodule is a growth in the thyroid gland. About half of adults actually have a thyroid nodule by age 60. Only five percent of them can be felt and the rest are so small they can only be detected by ultrasound. The good news is that over 90 percent of them are benign.

How often do benign thyroid nodules turn into cancer?

We don’t know the exact number, but based on the data we do have it appears to be very low. In a large study looking at changes in benign nodules over five years, only 0.3 percent became cancer.

How common is thyroid cancer?

Thyroid cancer cases have slowly been increasing over the past decade, but compared to other cancers it is relatively uncommon. Thyroid cancer represents only about three percent of all new cancer cases. Women are three times more likely to develop thyroid cancer than men.

What are the symptoms of thyroid cancer?

  • A lump in the neck, sometimes growing quickly
  • Swelling in the neck
  • Pain in the front of the neck, sometimes going up to the ears
  • Hoarseness or other voice changes that do not go away
  • Trouble swallowing
  • Trouble breathing
  • A constant cough that is not due to a cold

What is the prognosis for thyroid cancer?

Most thyroid cancers have a very good prognosis. In fact, the five-year survival for thyroid cancer is over 98 percent. That’s because most thyroid cancers are what we call “well differentiated,” which means they haven’t changed much from the thyroid cells they started out as, so they do not tend to spread. The most common type of thyroid cancer is called papillary cancer and it grows very, very slowly. When papillary thyroid cancer is found and it hasn’t spread at all, five-year survival is basically 100 percent.

How is thyroid cancer treated?

Thyroid cancer that hasn’t spread beyond the thyroid is usually treated with surgery to remove the cancer cells. A surgeon will typically remove either half, or all, of the thyroid gland. Surgery alone is often enough, but in some cases, radioactive iodine can be given after surgery to further eliminate cancer cells. Since the thyroid is usually removed, many people will need to take thyroid hormone after surgery.

Do you need a thyroid guard while getting a mammogram?

If you’ve ever worn a lead apron while getting an X-ray, you may have noticed that some are equipped with a flap that can cover the neck. This protects the thyroid gland from any potential radiation that may come from the X-ray machine. Many studies have looked into whether or not this thyroid guard is even necessary. The general consensus is that the amount of radiation your thyroid is exposed to during a mammogram is very low and likely does not increase your risk of thyroid cancer, even over the course of several mammograms throughout a lifetime. In fact, a 2012 study published by The National Center for Biotechnology Information found that using a thyroid guard may actually increase the chance of needing to redo your mammogram, which would end up exposing you to even more radiation. If you'd still prefer a thyroid guard during your next X-ray, check ahead of time to see if the technician has them available. 

Related:

What to Know About Thyroid Cancer

Thyroid Cancer Neck-Check

5 Surprising Foods That Can Help Your Thyroid

Article written by Michael Crupain, MD, MPH
Michael Crupain, MD, MPH is the Chief of Staff of the Medical Unit at The Dr. Oz Show.