Why are hormones used to treat thyroid cancer?

Hormones are not the first-line treatment for thyroid cancer. However, they might be used as a part of postoperative treatment for certain types of thyroid cancer:

1. Thyroid Hormone Replacement Therapy:

After thyroidectomy (surgical removal of the thyroid gland), patients with thyroid cancer may require lifelong thyroid hormone replacement therapy to maintain normal thyroid function. This helps the body maintain a normal metabolic rate, prevent symptoms of hypothyroidism, and suppress the production of thyroid-stimulating hormone (TSH). TSH can stimulate the growth of any remaining thyroid cancer cells.

2. Thyroid Hormone Suppressive Therapy:

In certain cases where thyroid cancer has spread to other parts of the body (metastatic disease), thyroid hormone suppressive therapy may be used. This involves administering high doses of thyroid hormone beyond what the body needs, which aims to suppress TSH levels and inhibit the growth of thyroid cancer cells.

3. Radioactive Iodine Therapy:

Radioactive iodine (RAI), a form of radiation therapy, can also be considered a hormonal treatment in some cases. The thyroid gland, including thyroid cancer cells, has an affinity for iodine. RAI therapy involves administering radioactive iodine, which the thyroid tissue absorbs. The radiation subsequently destroys thyroid cancer cells while minimizing harm to healthy tissues.

Hormonal treatment for thyroid cancer is usually combined with other therapies, such as surgery or radioactive iodine therapy, and is closely monitored by an endocrinologist. However, hormonal therapy is not used in all cases of thyroid cancer and depends on various factors such as the type and stage of the cancer.