Thyroid Issues After Childhood Cancer Treatment
What’s the risk?
The thyroid gland is located in the neck. Radiation fields that include the thyroid gland or reach close to the thyroid gland can result in a variety of thyroid problems, including hypothyroidism, hyperthyroidism, and thyroid nodules/tumors. Although risk continues for the life of a survivor, peak incidence of hypo and hyperthyroidism has most often been seen at 2-5 years after treatment, while thyroid nodules are typically seen 10 years or more after treatment. Risk increases with the amount of radiation received to the area.
Symptoms/When to Call
Symptoms of hypothyroidism (the most common complication) include fatigue, weight gain, constipation, dry skin, brittle hair or cold intolerance. Thyroid nodules present as a painless bump or lump in your neck.
Prevention and Treatment
Survivors who have had radiation and/or symptoms of hypothyroidism can have thyroid function tests (blood tests, such as a TSH) checked with routine labs. If someone is found to be hypothyroid, they are started on thyroid hormone replacement and blood tests are monitored to ensure the correct level of medication over time.
In addition, anyone who received radiation to the neck area should have their thyroid gland examined for any nodules. Your primary care provider would do this by feeling the thyroid gland during your annual physical exam. Any concerns on physical exam would prompt further evaluation with imaging (a thyroid ultrasound), which can help understand if the nodules are benign (not cancerous) or concerning (possibly cancerous). If the nodules look concerning, a biopsy (FNA or fine needle aspiration) is performed. The good news is thyroid cancer is curable. Cancers found early can be treated, often with removal of the thyroid gland.