Learn the signs, risk factors, and treatment options for the most common form of thyroid cancer.
If you’ve been diagnosed with papillary thyroid cancer, or you know someone who has, you might have a lot of questions. Papillary thyroid cancer, also called papillary thyroid carcinoma, is a type of cancer that starts in the follicular cells of the thyroid gland in your neck, according to the National Library of Medicine (NLM). Follicular cells make a protein called thyroglobulin, which your thyroid uses to produce its hormones.
Papillary thyroid cancer is the most common type of thyroid cancer. Up to 85% of all thyroid cancers are this type, per the NLM.
While any cancer diagnosis can be scary, the outlook for papillary thyroid cancer is very positive, says Allen Ho, M.D., codirector of the Thyroid Cancer Program and director of the Head and Neck Cancer Program at Cedars-Sinai in Los Angeles, CA. “Most thyroid cancer is eminently curable,” he says.
Let’s take a closer look at this cancer, who it affects, and how it’s diagnosed and treated.
Papillary thyroid cancer is somewhat rare compared to other cancers. Just under 44,000 people are diagnosed with thyroid cancer each year, according to the American Cancer Society, and most have the papillary type. In comparison, 238,000 people are diagnosed annually with lung cancer and more than 300,000 with breast cancer, based on American Cancer Society statistics.
Though you can get this cancer at any age, it’s usually diagnosed in people ages 30 to 50, according to the Mayo Clinic. Women are almost three times more likely to get papillary thyroid cancer than men, per a study on gender disparities in thyroid cancer published in the journal Future Oncology. That difference might have to do with hormonal changes during a woman’s menstrual periods and during pregnancy.
In addition, “this cancer is more common in people who’ve been exposed to radiation of the neck—such as those who were treated for head and neck cancers—and in those with autoimmune thyroid disease,” says Priyanka Iyer, M.B.B.S., an assistant professor of endocrine neoplasia and hormonal disorders at MD Anderson Cancer Center in Houston, TX. (An M.B.B.S. degree is the equivalent of an M.D. in some countries in Europe and Asia, including India.)
Papillary thyroid cancer often grows very slowly, but it can escape from the thyroid into lymph nodes in the neck, says the American Cancer Society. From there, it can reach organs like the lungs and bones. When it spreads, doctors call it metastatic papillary thyroid cancer.
Staging is the process your doctor will use to determine whether the cancer has spread, and if so, how far, so they can choose the right treatment. Papillary thyroid cancer stages go from 1 to 4. The higher the stage, the more the cancer has spread, per the American Cancer Society.
Most people with this cancer don’t have any noticeable symptoms, says Dr. Ho. “I would say in 80% of patients, the cancers are found incidentally. Another way to put that is they’re found accidentally when doctors are looking for other things.” An example he gives is if you went to the emergency room after a car accident, and a CT scan of your spine revealed a growth on your thyroid gland.
If the cancer grows large enough, it can cause a lump in your neck. You might notice the lump when you touch your neck, or your doctor might find it during an exam, says Dr. Ho.
Other possible symptoms of papillary thyroid cancer, according to the Mayo Clinic, are:
Hoarseness or other changes to your voice
Pain in your neck or throat
Swollen glands in your neck
Trouble swallowing
These types of symptoms are always worth checking out with your doctor.
What causes most papillary thyroid cancers to start growing remains somewhat of a mystery. Genes are likely involved, but not the kind you inherit from your parents. These are DNA changes, or mutations, that happen randomly as cells in the thyroid divide. “The vast majority of these [DNA changes] are sporadic,” says Dr. Ho.
Although it’s not clear exactly what causes papillary thyroid cancer to develop, there are several known risk factors. According to the American Society of Clinical Oncology, these include:
Being of Asian or white ethnicity
Being between the ages of 20 and 55
Being exposed to radiation to the head and neck as a child or being exposed to radioactive fallout
Being female
Having a family history of precancerous polyps in the colon (this can occur due to a rare inherited condition called familial adenomatous polyposis)
Having a first-degree relative (parent, sibling, or child) who had papillary thyroid cancer
If your doctor suspects you may have thyroid cancer, he or she may order tests to diagnose the cancer and find out if it has spread. Tests you may have include:
The diagnostic process usually starts with a neck ultrasound, which uses sound waves to take pictures from inside the neck. “Although it seems very low-tech, it’s actually quite good for [identifying] the nodule,” Dr. Ho says. “Some nodules look very benign, or harmless. They just look like a cyst. Other ones look very suspicious. And then there are ones in between.” The suspicious and in-between growths will need further testing.
Your doctor might order one or more of these additional imaging tests to confirm the diagnosis or determine whether the cancer has spread, according to the NLM—and if so, to where:
Computed tomography (CT). This is a series of X-rays taken from different angles that produces detailed images from inside your body. You may get a contrast dye (usually by injection into a vein in your arm) first to more clearly outline structures in your neck.
Magnetic resonance imaging (MRI). MRI uses radio waves and strong magnets, so it doesn’t expose you to any radiation. You may get a contrast material(also by injection) before the scan to make the cancer show up more clearly.
Positron emission tomography (PET)/CT. For this test, you’ll get an injection of a radioactive sugar, which highlights any areas of abnormal activity (cancer). This test can also show whether the cancer has come back after surgery.
For a suspicious or in-between lump, your doctor will likely order a needle biopsy. That’s when the doctor uses a very thin needle to remove a small piece of tissue from your thyroid gland. The sample goes to a lab, where a specialist looks at it under a microscope to see if it’s cancer, according to the Cleveland Clinic.
If the results are still unclear, your doctor might run the sample through molecular testing to see if the cells have any gene mutations. “If the molecular testing comes back with no mutations, we think the chance of it being cancer is zero,” says Dr. Ho. If a mutation is found, the risk of cancer increases.
Your biopsy results will also help your doctor decide what treatment to recommend. For example, if the cancer has certain gene mutations, targeted drugs may work against it, Dr. Ho says.
Blood tests can’t diagnose papillary thyroid cancer, but they can show whether your thyroid gland is working properly. Substances your doctor will check the level of include:
Thyroid-stimulating hormone (TSH)
Thyroid hormone (T3 and T4)
Thyroglobulin, a protein made by the thyroid. Cells from common types of thyroid cancer, including papillary thyroid cancer, also release thyroglobulin, which could make your level higher than it would normally be, according to the NLM. Doctors also use thyroglobulin levels to monitor for cancer recurrence after surgery or radioactive iodine therapy.
Thyroid tumors can sometimes affect your vocal cords, per the American Cancer Society. Even if your voice sounds normal, your vocal cords may not be working normally. Your doctor may look down your throat with a special thin tube that has a light and a lens on the end to view your larynx (voice box).
The main treatment for nearly everyone with papillary thyroid cancer is surgery, says the American Cancer Society. Radioactive iodine and targeted drugs might also be added in certain situations.
Surgery to remove part or all of the thyroid gland is the standard of care for most people with papillary thyroid cancer, says Dr. Ho. If the whole gland is removed, it’s called a thyroidectomy; if only the part (lobe) containing the cancer is removed, that’s a lobectomy.
The decision of how much of the gland to remove usually comes down to the size of the tumor, says Dr. Ho:
If the cancer is less than 1 centimeter and hasn’t spread, doctors often do a lobectomy.
If the cancer measures 1 to 4 centimeters and hasn’t spread, your doctor might offer you the choice between a lobectomy or a thyroidectomy.
If the cancer is larger than 4 centimeters, the standard procedure is to remove the whole gland.
After thyroidectomy you’ll need to take thyroid hormone medicine for the rest of your life. But if your surgeon only removes half of your thyroid, the remaining half may make enough thyroid hormone to meet your needs. If this is the case, you can skip thyroid hormone medicine or take a smaller dose, says Dr. Ho.
If the cancer has spread to lymph nodes in your neck, your surgeon will remove them at the same time as your thyroid surgery, per the American Cancer Society.
The thyroid gland is uniquely effective at absorbing iodine, which the cells of the gland use to make thyroid hormone. Thyroid cancer cells also absorb iodine well. For this reason, radioactive iodine is a very effective targeted treatment for papillary thyroid cancer, according to the American Cancer Society. The cancer cells absorb this special iodine, and the radioactive material in it kills them.
The catch is that you can only have this treatment after having a thyroidectomy, Dr. Ho says. That’s because the radioactive iodine would destroy healthy thyroid tissue. Instead, radioactive iodine is used after surgery to target any cancerous cells that may be left after the procedure, killing them from within.
You’ll get the radioactive iodine either by mouth (pill) or through a vein (injection). Because your body will give off radiation for a few days after this treatment, you’ll need to either stay in the hospital or take special precautions at home (which your medical team will explain to you) to protect people around you from radiation exposure, says the American Cancer Society.
Possible side effects from radioactive iodine are usually short-lived, per the American Cancer Society, and include:
Dry mouth and dry eye
Fertility problems
Nausea and vomiting
Swelling and soreness in the neck and salivary glands
Taste changes
People who’ve had this treatment may be at slightly higher risk for certain cancers in the future, including leukemia, stomach cancer, and salivary gland cancer. Your doctor might do extra screenings to monitor you more closely for cancer after treatment.
A few new medicines target proteins or gene changes that help certain papillary thyroid cancers grow, according to the American Cancer Society. These include:
Cabometyx (cabozantinib)
Lenvima (lenvatinib)
Mekinist (trametinib)
Nexavar (sorafenib)
Retevmo (selpercatinib)
Rozlytrek (entrectinib)
Tafinlar (dabrafenib)
Vitrakvi (larotrectinib)
Zelboraf (vemurafenib)
These medications might be an option if surgery and radioactive iodine haven’t stopped your cancer.
The outlook for papillary thyroid cancer is “outstanding,” says Dr. Ho. One reason is that this cancer tends to grow very slowly. People who are diagnosed with any stage of papillary thyroid cancer are more than 99% as likely to survive for five years as people who don’t have this cancer, according to the American Cancer Society.
Interestingly enough, one factor that could affect your outlook is your age. “Generally, most people under age 55 do really well,” says Dr. Iyer. “In older people, there is a higher chance of the cancer spreading to other organs or transforming into a more aggressive form of thyroid cancer. However, this number still remains fairly small, and even when the cancer has spread there are treatment options available.”
Papillary thyroid cancer is the most common type of thyroid cancer, but it is still relatively uncommon compared to other cancer types. If you are diagnosed with this cancer, know that the outlook is very positive. Therapies like surgery and radioactive iodine make papillary thyroid cancer highly treatable.
What Is Papillary Thyroid Cancer?: StatPearls. (2023.) “Papillary Thyroid Carcinoma.” https://www.ncbi.nlm.nih.gov/books/NBK536943/
At What Age Is This Cancer Diagnosed?: Mayo Clinic. (2023.) “Thyroid Cancer.” https://www.mayoclinic.org/diseases-conditions/thyroid-cancer/symptoms-causes/syc-20354161
Gender and Papillary Thyroid Cancer: Future Oncology. (2010.) “Thyroid Cancer Gender Disparity.” https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3077966/
How Common is Papillary Thyroid Cancer? (1.): American Cancer Society. (2023.) “Key Statistics for Thyroid Cancer.” https://www.cancer.org/cancer/types/thyroid-cancer/about/key-statistics.html
How Common is Papillary Thyroid Cancer? (2.): American Cancer Society. (2023.) “Cancer Facts & Figures 2023.” https://www.cancer.org/content/dam/cancer-org/research/cancer-facts-and-statistics/annual-cancer-facts-and-figures/2023/2023-cancer-facts-and-figures.pdf
Where Does Papillary Thyroid Cancer Spread?: American Cancer Society. (2019.) “Papillary Thyroid Cancer.” https://www.cancer.org/cancer/types/thyroid-cancer/if-you-have-thyroid-cancer.html
What Is a Needle Biopsy?: Cleveland Clinic. (2022.) “Papillary Thyroid Cancer (PTC).” https://my.clevelandclinic.org/health/diseases/23382-papillary-thyroid-cancer-ptc
Blood Tests for Papillary Thyroid Cancer: American Cancer Society. (2020.) “Tests for Thyroid Cancer.” https://www.cancer.org/cancer/types/thyroid-cancer/detection-diagnosis-staging/how-diagnosed.html
Treating Papillary Thyroid Cancer: American Cancer Society. (2019.) “Surgery for Thyroid Cancer.” https://www.cancer.org/cancer/types/thyroid-cancer/treating/surgery.html
Radioactive Iodine Treatment: American Cancer Society. (2023.) “Radioactive Iodine (Radioiodine) Therapy for Thyroid Cancer.” https://www.cancer.org/cancer/types/thyroid-cancer/treating/radioactive-iodine.html
Targeted Therapy: American Cancer Society. (2023.) “Targeted Drug Therapy for Thyroid Cancer.” https://www.cancer.org/cancer/types/thyroid-cancer/treating/targeted-therapy.html
Outlook for Papillary Thyroid Cancer: American Cancer Society. (2023.) “Thyroid Cancer Survival Rates, by Type and Stage.” https://www.cancer.org/cancer/types/thyroid-cancer/detection-diagnosis-staging/survival-rates.html
What Is Papillary Thyroid Cancer?: StatPearls. (2023.) “Papillary Thyroid Carcinoma.” https://www.ncbi.nlm.nih.gov/books/NBK536943/
At What Age Is This Cancer Diagnosed?: Mayo Clinic. (2023.) “Thyroid Cancer.” https://www.mayoclinic.org/diseases-conditions/thyroid-cancer/symptoms-causes/syc-20354161
Gender and Papillary Thyroid Cancer: Future Oncology. (2010.) “Thyroid Cancer Gender Disparity.” https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3077966/
How Common is Papillary Thyroid Cancer? (1.): American Cancer Society. (2023.) “Key Statistics for Thyroid Cancer.” https://www.cancer.org/cancer/types/thyroid-cancer/about/key-statistics.html
How Common is Papillary Thyroid Cancer? (2.): American Cancer Society. (2023.) “Cancer Facts & Figures 2023.” https://www.cancer.org/content/dam/cancer-org/research/cancer-facts-and-statistics/annual-cancer-facts-and-figures/2023/2023-cancer-facts-and-figures.pdf
Where Does Papillary Thyroid Cancer Spread?: American Cancer Society. (2019.) “Papillary Thyroid Cancer.” https://www.cancer.org/cancer/types/thyroid-cancer/if-you-have-thyroid-cancer.html
What Is a Needle Biopsy?: Cleveland Clinic. (2022.) “Papillary Thyroid Cancer (PTC).” https://my.clevelandclinic.org/health/diseases/23382-papillary-thyroid-cancer-ptc
Blood Tests for Papillary Thyroid Cancer: American Cancer Society. (2020.) “Tests for Thyroid Cancer.” https://www.cancer.org/cancer/types/thyroid-cancer/detection-diagnosis-staging/how-diagnosed.html
Treating Papillary Thyroid Cancer: American Cancer Society. (2019.) “Surgery for Thyroid Cancer.” https://www.cancer.org/cancer/types/thyroid-cancer/treating/surgery.html
Radioactive Iodine Treatment: American Cancer Society. (2023.) “Radioactive Iodine (Radioiodine) Therapy for Thyroid Cancer.” https://www.cancer.org/cancer/types/thyroid-cancer/treating/radioactive-iodine.html
Targeted Therapy: American Cancer Society. (2023.) “Targeted Drug Therapy for Thyroid Cancer.” https://www.cancer.org/cancer/types/thyroid-cancer/treating/targeted-therapy.html
Outlook for Papillary Thyroid Cancer: American Cancer Society. (2023.) “Thyroid Cancer Survival Rates, by Type and Stage.” https://www.cancer.org/cancer/types/thyroid-cancer/detection-diagnosis-staging/survival-rates.html
