Key Points for This Section

Childhood cancer survivors may have late effects that affect the thyroid. Certain factors increase the risk that thyroid problems will occur. Thyroid late effects may be caused by treatment for certain childhood cancers.

Childhood cancer survivors may have late effects that affect the thyroid.

Thyroid late effects may include the following:

• Hypothyroidism (not enough thyroid hormone).
• Hyperthyroidism (too much thyroid hormone).
• Goiter.
• Lumps in the thyroid.

Certain factors increase the risk that thyroid problems will occur.

The risk of thyroid late effects may be increased in childhood cancer survivors who received either of the following:

• Radiation therapy to the head and neck.
• Total-body irradiation (TBI) as part of a stem cell transplant.

The risk may also be greater in females and may increase as the amount of time since diagnosis gets longer.

Thyroid late effects may be caused by treatment for certain childhood cancers.

Treatment for these and other childhood cancers may cause thyroid late effects:

• Acute lymphoblastic leukemia (ALL).
• Brain tumors.
• Hodgkin lymphoma.
• Head and neck cancers.

Glossary Terms

An aggressive (fast-growing) type of leukemia (blood cancer) in which too many lymphoblasts (immature white blood cells) are found in the blood and bone marrow. Also called ALL and acute lymphocytic leukemia.

The growth of abnormal cells in the tissues of the brain. Brain tumors can be benign (non-cancerous) or malignant (cancerous).

A term for diseases in which abnormal cells divide without control. Cancer cells can invade nearby tissues and can spread to other parts of the body through the blood and lymph systems. There are several main types of cancer. Carcinoma is cancer that begins in the skin or in tissues that line or cover internal organs. Sarcoma is cancer that begins in bone, cartilage, fat, muscle, blood vessels, or other connective or supportive tissue. Leukemia is cancer that starts in blood-forming tissue such as the bone marrow, and causes large numbers of abnormal blood cells to be produced and enter the blood. Lymphoma and multiple myeloma are cancers that begin in the cells of the immune system. Central nervous system cancers are cancers that begin in the tissues of the brain and spinal cord.

The process of identifying a disease, such as cancer, from its signs and symptoms.

An enlarged thyroid. It may be caused by too little iodine in the diet or by other conditions. Most goiters are not cancer.

A cancer of the immune system that is marked by the presence of a type of cell called the Reed-Sternberg cell. The two major types of Hodgkin lymphoma are classical Hodgkin lymphoma and nodular lymphocyte-predominant Hodgkin lymphoma. Symptoms include the painless enlargement of lymph nodes, spleen, or other immune tissue. Other symptoms include fever, weight loss, fatigue, or night sweats. Also called Hodgkin disease.

Too much thyroid hormone. Symptoms include weight loss, chest pain, cramps, diarrhea, and nervousness. Also called overactive thyroid.

Too little thyroid hormone. Symptoms include weight gain, constipation, dry skin, and sensitivity to the cold. Also called underactive thyroid.

Side effects of cancer treatment that appear months or years after treatment has ended. Late effects include physical and mental problems and second cancers.

The use of high-energy radiation from x-rays, gamma rays, neutrons, protons, and other sources to kill cancer cells and shrink tumors. Radiation may come from a machine outside the body (external-beam radiation therapy), or it may come from radioactive material placed in the body near cancer cells (internal radiation therapy). Systemic radiation therapy uses a radioactive substance, such as a radiolabeled monoclonal antibody, that travels in the blood to tissues throughout the body. Also called radiotherapy and irradiation.

A method of replacing immature blood-forming cells that were destroyed by cancer treatment. The stem cells are given to the person after treatment to help the bone marrow recover and continue producing healthy blood cells.

A gland located beneath the voice box (larynx) that makes thyroid hormone and calcitonin. The thyroid helps regulate growth and metabolism.

A hormone that affects heart rate, blood pressure, body temperature, and weight. Thyroid hormone is made by the thyroid gland and can also be made in the laboratory.

Radiation therapy to the entire body. It is usually followed by bone marrow or peripheral stem cell transplantation.