Survivorship: Health Concerns After Thyroidectomy

Hypothyroidism

Hypothyroidism is a low level of thyroid hormone production. You can have hypothyroidism after having some or all of your thyroid removed. The medication levothyroxine is taken to replace thyroid hormones. Surgery for thyroid cancer may remove part or all of the thyroid, nearby lymph nodes, and the parathyroid glands. You may need to take medicine (thyroid hormone) and vitamin and mineral supplements (vitamin D and calcium) for the rest of your life, to replace what is lost without these organs. You may benefit from referral to an endocrinologist to manage thyroid levels, replacement treatment, and ongoing care.

Taking Levothyroxine (Synthroid)

The goal of this medicine is to stop thyroid-stimulating hormone (TSH) from being made by your body. By keeping TSH suppressed, the growth of any remaining thyroid cancer cells slows down, which lowers the chance of cancer coming back (called recurrence). It is important to have your blood levels checked to be sure you are taking the correct dose.

Notes about levothyroxine:

• Take this medication in the morning, 30-60 minutes before eating, and with a full glass of water.
• Can interact with other medications or vitamins/supplements. You should talk to a pharmacist about any medications you are taking or starting.
• Try to avoid a high-fiber diet, soy-containing supplements, and walnuts. They can interfere with how levothyroxine works.
• You may get a rash or lose some hair during the first months of treatment.
• Too much thyroid hormone (hyperthyroidism) may cause you to lose weight, become irritable, have sleep disturbances, changes in appetite, have more frequent than normal bowel movements, decreased menstrual flow, tremors, muscle weakness, and feel hot and sweaty. It may also cause chest pain, cramps, and diarrhea.
• If the thyroid hormone level is too low (hypothyroidism), you may gain weight, feel tired, fatigued, depressed, have trouble concentrating, have hoarseness, joint pains, muscle cramps, constipation, changes in the menstrual cycle, feel cold, have dry skin, or brittle hair.
• Call your provider with any changes in how you are feeling.

Levothyroxine can cause problems for people with heart disease, clotting disorders, diabetes, and disorders of the adrenal or pituitary glands. Please be sure to tell your provider if you have or develop one of these health conditions. Levothyroxine is safe to take while pregnant and breastfeeding, but you may need to have blood work checked more often during this time.

Long-Term Health Concerns When Taking Levothyroxine

There are some long-term risks of continued TSH suppression. These include:

• Heart problems: atrial fibrillation (an irregular heartbeat) and an exacerbation of angina (chest pain)
• Women may be at higher risk for osteoporosis, especially those who are postmenopausal.

Hypoparathyroidism

If your entire thyroid was removed (thyroidectomy) or you received radiation and/or I-131 therapy, hypoparathyroidism can also occur. Hypoparathyroidism is a result of damage to or removal of the parathyroid glands, which are located behind the thyroid gland. Loss of these glands results in a lack of parathyroid hormone. Parathyroid hormone regulates calcium and phosphorus in the blood.

Symptoms of hypoparathyroidism include numbness and tingling around the lips, fingers, and toes, muscle cramps, or spasms. Management of hypoparathyroidism includes:

• Taking vitamin D and calcium supplements.
• Frequent blood tests to check your levels of calcium, phosphorus, and magnesium.
• An electrocardiogram (ECG or EKG) may be done to check for arrhythmia (irregular heartbeat), which can be caused by low calcium levels and hypoparathyroidism.
• You may have a bone density test before starting treatment, which looks at your bone health (checking for osteoporosis and osteopenia).

Other Long-Term Effects of Surgery

In some cases, certain nerves or muscles may be damaged or removed during thyroid surgery. If this happens, you may have voice changes, such as hoarseness or loss of voice, or one shoulder may hang lower than the other. Talk to your provider or work with a rehabilitation physician (called a physiatrist) if you develop any of these issues.

Considerations for Survivors of Medullary Thyroid Cancer

If you have been treated for medullary thyroid cancer (MTC) you should meet with a genetic counselor and have genetic testing. Some cases of MTC result from a genetic abnormality that can run in families. Genetic testing can look for a mutation (abnormality) in the RET gene, which occurs in both MTC and MEN-2 (multiple endocrine neoplasia type 2) syndromes.

People with MEN-2 syndromes are at increased risk for two specific tumors, pheochromocytoma and parathyroid adenoma. If you have one of these mutations, it is very important that your family is also tested, including children and pre-teens. Almost all children and adults with these genetic mutations will develop MTC. For this reason, it is recommended that people with these mutations undergo a total thyroidectomy to prevent MTC from developing.

Survivors of MTC should also have additional blood work checked. Along with thyroid function tests and thyroglobulin levels, calcitonin, and carcinoembryonic antigen (CEA) should be checked. If these levels begin to rise, a CT scan or MRI may be done to see if there is cancer recurrence.