12 Thyroid Cancer Facts Everyone Should Know

Your thyroid, the small butterfly-shaped gland in your neck, greatly impacts your entire body. Normally measuring 1.5–2.5 inches wide, the thyroid produces thyroid hormone (TH). TH regulates your body's metabolism, heartbeat, temperature, mood, and other important processes, which impact nearly every single cell in your body.

However, the thyroid doesn't always work as it should. In fact, about 20 million people in the United States have a thyroid disorder. Moreover, the American Cancer Society (ACS) reports that more than 43,000 people received a thyroid cancer diagnosis in the United States in 2022.

You may not be too concerned with thyroid cancer if you're relatively young and otherwise healthy. However, thyroid cancer can blindside you. Some cases of thyroid cancer are only discovered during routine checkups or imaging tests for other health issues.

Here are 12 things that you should know about thyroid cancer detection, treatment, and recovery.

Most Cases Are in People Younger Than 55

Generally, cancer is rare in young people. However, nearly two-thirds of people with cancer are younger than 55. About 2% of those are younger than 20.

"It is not that thyroid cancer is 'plaguing' younger people," Melanie Goldfarb, MD, an endocrine surgeon and director of the Endocrine Tumor Program at Providence Saint John's Health Center, told Health. However, it affects young people more than certain other cancers like prostate and lung.

About 40% of people with thyroid cancer are between the ages of 35 and 54 at the time of their diagnosis.

Women Are More at Risk

Females are three times more likely to get thyroid cancer than males, but scientists don't know the exact reason why.

Still, a review published in 2021 found that healthcare providers diagnose women and men with aggressive thyroid cancer at around the same rate. However, the researchers found that compared to men, women are more frequently diagnosed with small papillary thyroid cancer, which is rarely fatal. 

The researchers hypothesized that women are more likely than men to get tests for other medical reasons that find cancer, which would have otherwise gone undiagnosed.

Symptoms Can Be Sneaky

"Most patients don't have symptoms but could have discomfort in the neck or feel a lump," Kenneth D. Burman, MD, the director of the Endocrine Section at MedStar Georgetown University Hospital, told Health. 

Other thyroid cancer symptoms include:

• Hoarseness
• Trouble swallowing
• Trouble breathing
• Persistent coughing

It's easy to mistake symptoms of thyroid cancer for other health issues—or overlook them entirely. Some people may have a lump in their neck and not even notice it until their healthcare provider finds it during a routine checkup.

There's More Than One Type of Thyroid Cancer

There are three main types of thyroid cancer: differentiated, medullary, and anaplastic. 

Differentiated thyroid cancer, which looks very similar to normal thyroid tissue, includes:

• Papillary: This subtype makes up about 80% of thyroid cancers. Papillary carcinomas grow very slowly and usually develop in only one of the two lobes that make up the gland. While papillary carcinomas often spread to the lymph nodes in the neck, they are usually treatable and rarely fatal.
• Follicular: This subtype is more common in countries where people don't consume enough iodine. 
• Hürthle cell: This subtype is rare, affecting about 3% of people with thyroid cancer. Hürthle cell cancer is more difficult to treat.

Accounting for 4% of all cases, medullary thyroid cancer grows in C cells, which normally produce calcitonin. Calcitonin is a hormone involved in calcium metabolism. If caught and treated early, medullary thyroid cancer is easy to control before it can spread to other body parts.

Anaplastic thyroid cancer, which makes up 2% of all cases, sometimes develops from an existing papillary or follicular cancer. Anaplastic thyroid cancer often spreads quickly into the neck and other body parts. This type of thyroid cancer can be very hard to treat. 

Rarely, thyroid lymphoma begins in the thyroid's immune system cells and grows very quickly. Thyroid lymphoma typically occurs in older adults.

There Are Thyroid Cancer Risk Factors

The exact cause of most thyroid cancers is unclear. However, several factors may increase your risk, including:

• Radiation to the head and neck, especially during childhood
• Overweight or obesity
• Too much or too little iodine in the diet
• Rare genetic disorders, such as familial adenomatous polyposis (FAP), Cowden syndrome, and Carney complex (type 1)
• A family history of thyroid cancer

Also, know that although radiation to the head and neck links to thyroid cancer, researchers are unsure whether X-rays or CT scans also raise the risk.

There Are Several Ways To Diagnose Thyroid Cancer

Between 1973 and 2002, the incidence of thyroid cancer doubled. However, that trend may be due to an increase in detection and diagnosis, instead of a true increase in cases. 

"Thyroid ultrasound was in its infancy about 30 years ago. Now, they are being prescribed for any swelling of the neck," David Myssiorek, MD, an otolaryngologist at BronxCare Health System, told Health. Like an ultrasound technician drops a blob of cold lubricant on a pregnant person's belly, the same is done on the neck region. 

Ultrasound can help determine the following:

• The size of a nodule
• The number of nodules
• Whether a nodule is solid or filled with fluid
• Whether the lymph nodes are swollen, indicating cancer cells have spread

Ultrasound can also guide a needle into the nodule to take a biopsy.  

A positron emission tomography (PET) scan can also determine whether cancer cells have spread. With a PET scan, a healthcare provider injects a radioactive substance into the blood. Cancer cells absorb more of the substance than normal cells, making them appear on the scan. 

Other imaging tools, such as a chest X-ray and a CT or MRI scan, can also define the size of thyroid cancer and whether it has spread to other body parts.

Surgery Is the Main Treatment

Surgery is the main treatment in nearly every case of thyroid cancer, except for some anaplastic thyroid cancers. For example, thyroidectomy, one of the most common surgeries, involves removing the thyroid.

Also, a lobectomy removes the cancerous lobe. Usually, a healthcare provider performs a lobectomy if the person has small differentiated thyroid cancers that haven't spread. In contrast, if cancer cells have spread to the lymph nodes, the healthcare provider may also remove your lymph nodes.

Risks involved with thyroid surgery include accidental damage to the nerves connected to your vocal cords—which can cause vocal cord paralysis—hoarseness, soft voice, or difficulty breathing.

Getting Your Thyroid Removed Leads to Lifetime of Meds

After a complete thyroidectomy, you must take medication to replace TH and maintain your normal metabolism. Hormone therapy also stops any remaining cancer cells from growing by lowering thyroid-stimulating hormone (TSH) levels.

A healthcare provider tests those hormones with a blood test every few months until they determine the proper medication dose.

Radioactive Iodine Treatment Is Common

Often, a healthcare provider uses radioactive iodine treatment (RAI) after removing the thyroid to destroy any remaining thyroid tissue. They also use RAI to get rid of any microscopic areas of cancer cells left behind during surgery. 

You take RAI in either a pill or liquid form. Then, you must isolate yourself from others for at least three to five days.

Before undergoing RAI, healthcare providers advise a low-iodine diet to ultimately starve the body of the element, which helps produce TH. When RAI reintroduces iodine, the element will kill any remaining thyroid tissue and cancer cells.

"Think of thyroid tissue like a sponge," Steven I. Sherman, MD, a professor in the department of endocrine neoplasia and hormonal disorders at the University of Texas MD Anderson Medical Center, told Health. "For a sponge to soak up a maximum amount of water, first it must be wrung out of all the water it already contained."

Chemo Isn't Common

The role of chemotherapy, administered as an infusion through a vein to kill cancer cells, is minimal for the treatment of thyroid cancer.

Instead, if cancer cells grow after RAI, or if cancer spreads, oral drugs called tyrosine kinase inhibitors might be an option. This is especially true for anaplastic thyroid cancer, which has a poor prognosis but has targetable genetic alterations in about 40% of cases. Tyrosine kinase inhibitors also play an important role in the treatment of medullary cancer of the thyroid.

There are also local treatments like external beam radiation therapy, which uses high-energy rays to destroy or slow the growth of cancer cells, and alcohol ablation, which uses guided ultrasound imaging to inject small thyroid cancers with alcohol. However, these treatments are rarely used.

Alcohol ablation "is helpful for treating cancer that occurs in areas that aren't easily accessible during surgery and is not widely used to treat thyroid cancer," Khoi Dao, MD, a medical oncologist based in Nevada, told Health.

Sometimes Thyroid Cancer Is Called a "Good" Cancer

The five-year survival rate for most thyroid cancers is nearly 100% if caught and treated early before spreading beyond the neck.

In fact, in 2022, there were fewer than 2,500 deaths in the United States due to thyroid cancer. That's encouraging news for thyroid cancer survivors and newly diagnosed patients.

However, "I have yet to discover a 'good' cancer. Admittedly [thyroid cancers] are less aggressive, but anyone who says they are good doesn't have one," pointed out Dr. Myssiorek.

Self-Examining Your Neck Is Advisable and Easy

It's beneficial to perform self-exams on your throat to help detect any unwanted issues with your thyroid.

The first step is to find the thyroid gland. Don't confuse it with the Adam's apple, which is a bulky cartilage that moves up and down when you swallow. Some people have an Adam's apple, and others do not. If you do have an Adam's apple, then your thyroid gland is the next prominent cartilage below it, said Dr. Myssiorek. 

Place your fingers on either side of that prominence, just above the notch at the base of the neck, and swallow. If you feel lumps, contact a healthcare provider as soon as you can.

You can also perform the self-exam visually. Swallow some water while looking at the lower front area of your neck in the mirror. Contact your healthcare provider if you notice any areas of the thyroid gland that are more prominent when you swallow. Again, be sure not to confuse the thyroid gland with the Adam's apple, if you have one.

You may want to do this test multiple times.

A Quick Review

Thyroid cancer can appear in otherwise healthy young adults with no apparent symptoms. Therefore, being aware of the subtle signs, like trouble swallowing or persistent coughing, can help diagnose and treat thyroid cancer early. If caught early, most cases of thyroid cancer are treatable and typically don't involve chemotherapy.