How Thyroid Cancer Is Treated

Treatment for thyroid cancer depends on the specific type of thyroid cancer, how large it is, its location within the thyroid gland, overall health, and whether or not it has spread. Possible treatments include surgery, radioactive iodine therapy, radiation, chemotherapy, active surveillance, alcohol ablation, hormone therapy, and targeted drug therapy. Most cases of thyroid cancer can be cured with treatment.

This article describes the different treatments used for thyroid cancer, If you have been diagnosed with thyroid cancer, it's important to know that your treatment options will be specific to your situation.

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Surgeries

The majority of people with thyroid cancer have thyroid surgery at some point in the treatment process to remove all or part of the thyroid gland, and possibly nearby lymph nodes.

Thyroidectomy

A thyroidectomy is the surgical removal of the thyroid gland, and it's the most common surgery used for thyroid cancer.

• Total thyroidectomy: Removal of the entire thyroid gland
• Near-total thyroidectomy: Removal of almost all of the thyroid gland
• Subtotal thyroidectomy: Most of the thyroid gland is removed

This surgery is done through an incision that's a few inches long at the base of the front of the neck.

After a thyroidectomy, you may have radioactive iodine therapy and you will need to start taking levothyroxine, a thyroid hormone replacement, which goes by brand names Synthroid, Levoxyl, Levothroid, and others. This replaces thyroid hormones in the body once the thyroid gland is gone.

Thyroid Surgery During Pregnancy

If you're pregnant and you've been newly diagnosed with medullary or anaplastic thyroid cancer, the American Thyroid Association (ATA) recommends strongly considering a thyroidectomy during pregnancy, because waiting until after the baby is born can create a negative outcome.

Surgery may be necessary during the first 24 to 26 weeks of pregnancy for papillary thyroid cancer that has grown substantially (by 50 percent in volume and 20 percent in diameter in two dimensions). It also may be needed in cases where cancer has spread to the lymph nodes.

Lymph Node Removal

If your thyroid cancer spreads to nearby lymph nodes in your neck, your surgeon may remove these lymph nodes at the same time your thyroid cancer is removed.

If you have enlarged lymph nodes in the neck, they may be removed to be tested for cancer.

Lobectomy

Thyroidectomy is the most commonly used surgery for any type of thyroid cancer. A lobectomy is a surgery to remove one lobe of the thyroid instead of the entire gland. This procedure is sometimes used during diagnosis if a biopsy is unclear and, occasionally, to treat follicular thyroid cancer or papillary cancer.

In the United States, about 80 percent of all thyroid cancers are papillary cancer, which is more likely to show up on only one side (lobe) of the thyroid and usually grows very slowly.

If you have papillary thyroid cancer that fits within the following parameters, your surgeon may recommend a lobectomy:

• Your papillary thyroid cancer is stage I or II.
• The tumor is located in only one lobe of your thyroid.
• The tumor is 4 centimeters or less in size.

Because it can be performed on an outpatient basis and it's a shorter operation, a lobectomy is associated with a lower risk of complications and shorter recovery time, and patients report better quality of life afterward.

Another potential advantage is that you may not need to take thyroid hormone medication afterward, since some of your thyroid is retained, .

Specialist-Driven Procedures

There are several different procedures to treat different types and stages of thyroid cancer.

Radioactive Iodine Therapy

Radioactive iodine (RAI) therapy I-131, also known as radioiodine therapy, is a treatment that uses radioactive iodine. The material circulates throughout the body and becomes concentrated in the thyroid gland, where the iodine destroys the gland’s cells. Radioactive iodine is mainly absorbed by the thyroid cells with little effect on other cells. It's used to treat follicular and papillary thyroid cancer and hyperthyroidism (an overactive thyroid gland).

This therapy may also be used after a thyroidectomy to destroy any cancer cells that remain after surgery, treat thyroid cancer that has spread, or treat recurring thyroid cancer. 

Preparation: Before you have this treatment, you'll need to do some preparation.

• Low-iodine diet: Your healthcare provider will likely have you begin a low-iodine diet for one to two weeks before RAI treatment. You will need to eliminate things like iodized salt, red dye #3, cough medicine, seafood and fish, supplements containing iodine, dairy products, eggs, and soy. When you're given radioactive iodine, the iodine-starved thyroid cells absorb the RAI, destroying the cells.
• Stop thyroid hormone medication: RAI also works best if your thyroid-stimulating hormone (TSH or thyrotropin) blood level is high because TSH promotes the absorption of the radioactive iodine into any residual cancer cells. TSH will increase if your thyroid hormones are low. If you've had a thyroidectomy, you may need to temporarily stop taking your thyroid replacement for several weeks before you have RAI. The resulting low thyroid hormone levels can cause fatigue, depression, weight gain, muscle aches, thinning hair, dry skin, mood swings, difficulty concentrating, delayed reflexes, headaches, constipation, and insomnia.
• Thyrogen: Another way to raise TSH levels without having to stop your thyroid hormone medication is to get an injection of Thyrogen (thyrotropin alfa), a synthetic hormone that allows you to maintain proper thyroid function. Thyrogen is given in a series of shots over two days prior to RAI. During this time, you can continue taking your hormone medication without interruption. There may be a few side effects associated with the injections, mainly headache and nausea. Hives, itching, and flushing have also been known to occur, although these are considered rare. Thyrogen is not for everyone. Women who are pregnant or breastfeeding should not take it, nor should anyone who is allergic to any of the product’s ingredients.

What to Expect: The RAI procedure takes place in a hospital setting. You will be isolated from other people for several days because the after-effects of the treatment will cause you to become slightly radioactive.

You will ingest the radioactive iodine in either liquid form or as a capsule. You will need to refrain from eating so that your body can absorb the iodine. You will be able to eat and drink normally afterward, and you'll need to drink plenty of liquids to flush the radioactive iodine out of your system. When your radioactive levels have fallen, you will have a scan to determine where radioactivity has been absorbed in your body.

Once your levels of radioactivity fall to a safe level, you'll be sent home with post-care instructions. You will need to avoid contact with small children and pregnant or breastfeeding women for a period of time.

Side Effects: Depending on your age, overall health, and the amount of radioactive iodine you received, you may have one or more of the following short-term side effects:

• Swelling and inflammation of the salivary glands
• Dry mouth
• Changes in taste and sense of smell
• Nausea
• Neck swelling
• Constipation or diarrhea

Possible long-term side effects may include:

• Lower sperm counts in men
• Irregular menstrual cycles in women
• Reduced level of blood cells produced
• Risk of developing leukemia in the future
• Dry eye

External Radiation Therapy

External beam radiation therapy utilizes a machine that beams high-energy rays of radiation targeted to specific points on the body, which destroys or slows the growth of cancer cells. Similar to an X-ray, radiation is completely painless. It's usually administered for several minutes at a time, five days a week, for several weeks.

Radiation may be used if you're not a good candidate for surgery and radioactive iodine therapy hasn't worked, or if you have medullary or anaplastic thyroid cancer, which doesn't respond to radioactive iodine therapy. It's also sometimes used after surgery if there's concern about cancer coming back.

Side Effects: Radiation can destroy healthy tissue along with cancerous cells, which is why your healthcare provider will do careful measurements to make sure the beams are as accurate as possible and that you are getting the correct dose.

Other potential side effects include:

• Redness to your skin, similar to sunburn that typically fades
• Difficulty swallowing
• Dry mouth
• Hoarseness
• Fatigue

Chemotherapy

Chemotherapy treatments are powerful drugs that are usually infused into a vein (intravenously), injected into the muscle, or taken by mouth. They travel throughout the entire body, destroying cancer cells.

In general, common side effects include:

• Hair loss
• Mouth sores
• Appetite loss
• Vomiting
• Nausea
• Diarrhea
• Risk of infections
• Bruising and/or bleeding easily
• Fatigue

Chemotherapy does not play any role in the treatment of non-anaplastic thyroid cancer and it plays a minimal role in the treatment of anaplastic thyroid cancer. Immunotherapy (Pembrolizumab) is used in certain cases of thyroid cancer.

Active Surveillance

For some small, low-risk, slow-growing papillary types of thyroid cancer, experts are beginning to recommend a new approach: active surveillance. Low-risk means that cancer has not spread and the tumor doesn't extend outside of the thyroid gland.

The best candidates for this approach are people who are diagnosed after age 50 because these thyroid tumors tend to grow more slowly.

Benefits: This approach is beneficial for a number of reasons. First, thanks to technological advances, papillary thyroid cancer is detected far more often than it used to be. Second, the wait-and-see approach moves away from the tendency to immediately rush to surgery once a cancer diagnosis is made. Third, many people who are diagnosed with small papillary thyroid cancer won't need surgery for years, if ever.

Pregnancy: Active surveillance is recommended by the ATA for pregnant women who have been diagnosed with papillary thyroid cancer early in their pregnancy.

The cancer should be routinely monitored with ultrasound. If it starts to grow 50 percent in volume and 20 percent in diameter in two dimensions by 24 to 26 weeks' gestation, or if it has spread to lymph nodes, a thyroidectomy should be done in the second trimester—a time that has the least risks for both mother and baby. However, if the cancer remains stable or it's diagnosed in the second half of pregnancy, surgery can be put off until after the baby is born.

Research: One study monitored a group of patients who had very small—less than 1.5 millimeters in size—papillary thyroid tumors to see how they grew. Their tumor sizes were measured using three-dimensional ultrasound every six months to every year. After five years, only 12 percent of the tumors grew to 3 millimeters or more in size and cancer didn't spread at all in the patients studied during active surveillance.

The three-dimensional ultrasound was noted as being key in making active surveillance a viable option. Having a tumor measured with the 3D ultrasound every six months for the first two years of active surveillance establishes a growth rate. If the tumor starts growing fast, surgery can be initiated.

Active surveillance requires a specialized medical team that has experience with this method. You will need to have regular three-dimensional ultrasound scans, as well as regular checkups to keep an eye on your tumor.

Alcohol Ablation

Also known as ethanol ablation and percutaneous ethanol injection (PEI), alcohol ablation is a newer, cost-effective technique that's sometimes used for small papillary thyroid cancer.

With ultrasound guidance, the cancerous nodule is injected with alcohol, destroying the cancer cells. Alcohol ablation may be performed when cancer is located in areas that are hard to access through surgery or if you have recurrent thyroid cancer in small areas of your neck.

This procedure is not routinely used and studies are still being conducted on its overall effectiveness.

Prescriptions

There are two types of prescription drugs used to treat thyroid cancer: thyroid hormone therapy, which is very common, and targeted drug therapy, used much less often.

Thyroid Hormone Therapy

After a thyroidectomy, and often after a lobectomy, daily thyroid hormone medication is needed. You would have to take it for the rest of your life.

Synthroid (levothyroxine) replaces the thyroid hormone your body no longer makes since you've had your thyroid removed. It also works to keep TSH levels down, which reduces the chances of the cancer coming back since high TSH levels can trigger growth in any cancer cells that may be left.

Side effects: Levothyroxine has many potential side effects, some or all of which may go away in time, including:

• Weight loss
• Shakiness or tremor
• Headache
• Nausea
• Vomiting
• Diarrhea
• Abdominal cramps
• Feeling nervous
• Feeling irritable
• Difficulty sleeping
• Sweating more than normal
• Increased appetite
• Fever
• Menstrual changes
• Feeling sensitive to heat
• Temporary hair loss when you first start levothyroxine (more common in children)

Targeted Drug Therapy

There are newer drugs being developed that work by attacking certain targets in your cancer cells that cause them to change, grow, and divide. This type of treatment is more specific than chemotherapy, which destroys all fast-growing cells, including healthy ones, and it's typically used for people with advanced thyroid cancer.

For papillary and follicular thyroid cancer: Most people with papillary or follicular thyroid cancer respond well to surgery and radioiodine therapy, but for those who don't, the targeted drugs Nexavar (sorafenib) or Lenvima (lenvatinib) may help stop the cancer from progressing.

Known as tyrosine kinase inhibitors, these drugs keep tumors from growing by blocking certain growth-enhancing proteins they make and also sometimes cutting off the ability of tumors to develop new blood vessels.

Common side effects may include fatigue; rash; appetite loss; nausea; diarrhea; high blood pressure; and redness, swelling, pain, or blisters on the palms of your hands or the soles of your feet.

For medullary thyroid cancer: Since typical treatments for thyroid cancer like radioactive iodine therapy don't work well for medullary thyroid cancer, targeted drug therapy may be particularly helpful.

The drugs that treat this type of cancer are Caprelsa (vandetanib) and Cometriq (cabozantinib), both of which have been shown to help stop tumors from growing for a period of time. They are both pills taken by mouth once a day.

Because of the potential for rare but serious side effects, healthcare providers have to be specially trained in order to prescribe the medication.