KEY POINTS
- Thyroid gland
- Thyroid late effects are more likely to occur after treatment for certain childhood cancers.
- Radiation therapy to the head and neck increases the risk of thyroid late effects.
- Late effects that affect the thyroid may cause certain health problems.
- Signs and symptoms of thyroid late effects depend on whether there is too little or too much thyroid hormone in the body.
- Certain tests and procedures are used to diagnose health problems in the thyroid.
- Hypothalamus and pituitary gland
- Neuroendocrine late effects may be caused after treatment for certain childhood cancers.
- Treatment that affects the hypothalamus or pituitary gland increases the risk of neuroendocrine system late effects.
- Late effects that affect the hypothalamus may cause certain health problems.
- Certain tests and procedures are used to diagnose health problems in the neuroendocrine system.
- Testicles and ovaries
- Metabolic syndrome
- Metabolic syndrome is more likely to occur after treatment for certain childhood cancers.
- Radiation therapy increases the risk of metabolic syndrome.
- Certain tests and procedures are used to diagnose metabolic syndrome.
- Metabolic syndrome may cause heart and blood vessel disease and diabetes.
- Weight
- Being underweight, being overweight, or having obesity is a late effect that is more likely to occur after treatment for certain childhood cancers.
- Radiation therapy increases the risk of being underweight, being overweight, or having obesity.
- Certain tests and procedures are used to diagnose a change in weight.
Thyroid gland
Thyroid late effects are more likely to occur after treatment for certain childhood cancers.
Treatment for these and other childhood cancers may cause thyroid late effects:
- Acute lymphoblastic leukemia (ALL).
- Brain tumors.
- Head and neck cancers.
- Hodgkin lymphoma.
- Neuroblastoma.
- Cancers treated with a stem cell transplant.
Radiation therapy to the head and neck increases the risk of thyroid late effects.
The risk of thyroid late effects may be increased in childhood cancer survivors after treatment with any of the following:
- Radiation therapy to the thyroid as part of radiation therapy to the head and neck or to the pituitary gland in the brain.
- Total-body irradiation as part of a stem cell transplant.
- MIBG (radioactive iodine) therapy for neuroblastoma.
- Chemotherapy such as alkylating agents, anthracyclines, or bleomycin.
The risk also is increased in females, in survivors who were a young age at the time of treatment, in survivors who had a higher radiation dose, and as the time since diagnosis and treatment gets longer.
Late effects that affect the thyroid may cause certain health problems.
Thyroid late effects and related health problems include the following:
- Hypothyroidism (not enough thyroid hormone): There is a higher risk of hypothyroidism in survivors treated with head and neck radiation involving the thyroid gland, especially survivors of Hodgkin lymphoma. This is the most common thyroid late effect. It usually occurs 2 to 5 years after treatment ends but may occur longer than 25 years after radiation therapy. It is more common in girls than boys.
- Hyperthyroidism (too much thyroid hormone): The risk of hyperthyroidism increases with higher doses of radiation therapy to the thyroid gland. Hyperthyroidism is less common than hypothyroidism. It usually occurs 5 years after treatment ends, but may occur longer than 25 years after radiation therapy.
- Goiter (an enlarged thyroid).
- Lumps in the thyroid: Higher radiation dose and longer time since diagnosis are linked to an increased risk of developing thyroid lumps. These growths may be benign (not cancerous) or malignant (cancer). It is more common in girls than boys.
Signs and symptoms of thyroid late effects depend on whether there is too little or too much thyroid hormone in the body.
These and other signs and symptoms may be caused by thyroid late effects or by other conditions:
Hypothyroidism (too little thyroid hormone)
- Feeling tired or weak.
- Being more sensitive to cold.
- Pale, dry skin.
- Coarse and thinning hair.
- Brittle fingernails.
- Hoarse voice.
- Puffy face.
- Muscle and joint aches and stiffness.
- Constipation.
- Menstrual periods that are irregular or heavier than normal.
- Weight gain for no known reason.
- Depression or trouble with memory or being able to concentrate.
Rarely, hypothyroidism does not cause any symptoms.
Hyperthyroidism (too much thyroid hormone)
- Feeling nervous, anxious, or moody.
- Trouble sleeping.
- Feeling tired or weak.
- Having shaky hands.
- Having a fast heartbeat.
- Having red, warm skin that may be itchy.
- Having fine, soft hair that is falling out.
- Having frequent or loose bowel movements.
- Weight loss for no known reason.
- Being more sensitive to heat.
Talk to your child's doctor if your child has any of these problems.
Certain tests and procedures are used to diagnose health problems in the thyroid.
In addition to asking about your child’s personal and family health history and doing a physical exam, your child’s doctor may perform the following tests and procedures.
- Blood hormone studies: A procedure in which a blood sample is checked to measure the amounts of certain hormones released into the blood by organs and tissues in the body. An unusual (higher or lower than normal) amount of a substance can be a sign of disease in the organ or tissue that makes it. The blood may be checked for abnormal levels of thyroid-stimulating hormone (TSH) or free thyroxine (T4).
- Ultrasound exam: A procedure in which high-energy sound waves (ultrasound) are bounced off internal tissues or organs and make echoes. The echoes form a picture of body tissues called a sonogram. The picture can be printed to be looked at later. This procedure can show the size of the thyroid and whether there are nodules (lumps) on the thyroid.
Talk to your child's doctor about whether your child needs to have tests and procedures to check for signs of thyroid late effects. If tests are needed, find out how often they should be done.
Hypothalamus and pituitary gland
Neuroendocrine late effects may be caused after treatment for certain childhood cancers.
The neuroendocrine system is the nervous system and the endocrine system working together.
Treatment for these and other childhood cancers may cause neuroendocrine late effects:
- Acute lymphoblastic leukemia (ALL).
- Brain and spinal cord tumors.
- Cancers treated with total-body irradiation (TBI) before a stem cell transplant.
Treatment that affects the hypothalamus or pituitary gland increases the risk of neuroendocrine system late effects.
Childhood cancer survivors have an increased risk for neuroendocrine late effects. These effects are caused by radiation therapy to the brain in the area of the hypothalamus. The hypothalamus controls the way hormones are made and released into the bloodstream by the pituitary gland. Radiation therapy may be given to treat cancer near the hypothalamus or as total-body irradiation before a stem cell transplant. These effects are also caused by surgery in the area of the hypothalamus, pituitary gland, or optic pathways.
Childhood cancer survivors who have neuroendocrine late effects may have low levels of any of the following hormones made in the pituitary gland and released into the blood:
- Growth hormone (helps promote growth and control metabolism).
- Adrenocorticotropic hormone (ACTH; controls the making of glucocorticoids).
- Prolactin (controls the making of breast milk).
- Thyroid-stimulating hormone (TSH; controls the making of thyroid hormones).
- Luteinizing hormone (LH; controls reproduction).
- Follicle-stimulating hormone (FSH; controls reproduction).
Late effects that affect the hypothalamus may cause certain health problems.
Neuroendocrine late effects and related health problems include the following:
- Growth hormone deficiency: A low level of growth hormone is a common late effect of radiation to the brain in childhood cancer survivors. The higher the radiation dose and the longer the time since treatment, the greater the risk of this late effect. A low level of growth hormone may also occur in childhood ALL and stem cell transplant survivors who received radiation therapy to the brain and spinal cord and/or chemotherapy.
A low level of growth hormone in childhood results in adult height that is shorter than normal. If the child's bones have not fully developed, low growth hormone levels may be treated with growth hormone replacement therapy beginning one year after the end of treatment.
- Adrenocorticotropin deficiency: A low level of adrenocorticotropic hormone is an uncommon late effect. It may occur in childhood brain tumor survivors, survivors with low growth hormone levels or central hypothyroidism, or after radiation therapy to the brain.
Symptoms of deficiency may not be severe and may not be noticed. Signs and symptoms of adrenocorticotropin deficiency include the following:
- Weight loss for no known reason.
- Not feeling hungry.
- Nausea.
- Vomiting.
- Abdominal pain.
- Low blood pressure.
- Feeling tired.
- Dizziness.
Low levels of adrenocorticotropin may be treated with hydrocortisone therapy.
- Hyperprolactinemia: A high level of the hormone prolactin may occur after a high dose of radiation to the brain or surgery that affects part of the pituitary gland. A high level of prolactin may cause the following:
- Puberty at a later age than normal.
- Flow of breast milk in a woman who is not pregnant or breast-feeding.
- Less frequent or no menstrual periods or menstrual periods with a very light flow.
- Hot flashes.
- Inability to become pregnant.
- Inability to have an erection needed for sexual intercourse.
- Lower sex drive (in men and women).
- Osteopenia (low bone mineral density).
Sometimes there are no signs and symptoms. Treatment is rarely needed.
- Thyroid-stimulating hormone deficiency (central hypothyroidism): A low level of thyroid hormone may occur very slowly over time after radiation therapy to the brain.
Sometimes the symptoms of thyroid-stimulating hormone deficiency are not noticed. Low thyroid hormone levels may cause slow growth and delayed puberty, as well as other symptoms. A low level of thyroid hormone may be treated with thyroid hormone replacement therapy.
- Luteinizing hormone or follicle-stimulating hormone deficiency: Low levels of these hormones can cause different health problems. The type of problem depends on the radiation dose.
Childhood cancer survivors who were treated with lower doses of radiation to the brain may develop central precocious puberty (a condition that causes puberty to start before age 8 in girls and 9 in boys). This condition may be treated with gonadotropin-releasing hormone (GnRH) agonist therapy to delay puberty and help the child's growth. Hydrocephalus may also increase the risk of this late effect.
Childhood cancer survivors who were treated with higher doses of radiation to the brain may have low levels of luteinizing hormone or follicle-stimulating hormone. This condition may be treated with sex hormone replacement therapy. The dose will depend on the child's age and whether the child has reached puberty.
- Central diabetes insipidus: Central diabetes insipidus may be caused by the absence of or low amounts of all of the hormones made in the front part of the pituitary gland and released into the blood. It may occur in childhood cancer survivors treated with surgery in the area of the hypothalamus or pituitary gland. Signs and symptoms of central diabetes insipidus may include the following:
- Producing large amounts of urine.
- Feeling very thirsty.
- Fatigue.
- Slowed growth and development.
- Weight loss for no known reason.
Certain tests and procedures are used to diagnose health problems in the neuroendocrine system.
In addition to asking about your child’s personal and family health history and doing a physical exam, your child’s doctor may perform the following tests and procedures.
- Blood chemistry study: A procedure in which a blood sample is checked to measure the amounts of certain substances, such as glucose, released into the blood by organs and tissues in the body. An unusual (higher or lower than normal) amount of a substance can be a sign of disease.
- Blood hormone studies: A procedure in which a blood sample is checked to measure the amounts of certain hormones released into the blood by organs and tissues in the body. An unusual (higher or lower than normal) amount of a substance can be a sign of disease in the organ or tissue that makes it. The blood may be checked for abnormal levels of follicle-stimulating hormone, luteinizing hormone, estradiol, testosterone, cortisol, or free thyroxine (T4).
- Lipid profile studies: A procedure in which a blood sample is checked to measure the amounts of triglycerides, cholesterol, and low- and high-density lipoprotein cholesterol in the blood.
Talk to your child's doctor about whether your child needs to have tests and procedures to check for signs of neuroendocrine late effects. If tests are needed, find out how often they should be done.
Testicles and ovaries
For information about late effects in the testicles and ovaries, see the Reproductive System section.
Metabolic syndrome
Metabolic syndrome is more likely to occur after treatment for certain childhood cancers.
Metabolic syndrome is a group of medical conditions that includes having too much fat around the abdomen and at least two of the following:
- High blood pressure.
- High levels of triglycerides and low levels of high-density lipoprotein (HDL) cholesterol in the blood.
- High levels of glucose (sugar) in the blood.
Treatment for these and other childhood cancers may cause metabolic syndrome to occur later in life:
- Acute lymphoblastic leukemia (ALL).
- Cancers treated with a stem cell transplant.
- Cancers treated with radiation to the abdomen, such as Wilms tumor or neuroblastoma.
Radiation therapy increases the risk of metabolic syndrome.
The risk of metabolic syndrome may be increased in childhood cancer survivors after treatment with any of the following:
- Radiation therapy to the brain, abdomen, or pelvis.
- Total-body irradiation (TBI) as part of a stem cell transplant.
- Chemotherapy, such as alkylating agents.
- Older age.
Certain tests and procedures are used to diagnose metabolic syndrome.
In addition to asking about your child’s personal and family health history and doing a physical exam, your child’s doctor may perform the following tests and procedures.
- Blood chemistry studies: A procedure in which a blood sample is checked to measure the amounts of certain substances, such as glucose, released into the blood by organs and tissues in the body. An unusual (higher or lower than normal) amount of a substance can be a sign of disease.
- Lipid profile studies: A procedure in which a blood sample is checked to measure the amounts of triglycerides, cholesterol, and low- and high-density lipoprotein cholesterol in the blood.
Talk to your child's doctor about whether your child needs to have tests and procedures to check for signs of metabolic syndrome. If tests are needed, find out how often they should be done.
Metabolic syndrome may cause heart and blood vessel disease and diabetes.
Metabolic syndrome is linked to an increased risk of heart and blood vessel disease and diabetes. Health habits that decrease these risks include:
- Having a healthy weight.
- Eating a heart-healthy diet.
- Having regular exercise.
- Not smoking.
Weight
Being underweight, being overweight, or having obesity is a late effect that is more likely to occur after treatment for certain childhood cancers.
Treatment for these and other childhood cancers may cause a change in weight:
- Acute lymphoblastic leukemia (ALL).
- Brain tumors, especially craniopharyngiomas.
- Cancers treated with radiation to the brain, including TBI as part of a stem cell transplant.
Graft-versus-host disease may also cause a change in weight for patients treated with a stem cell transplant.
Radiation therapy increases the risk of being underweight, being overweight, or having obesity.
The risk of being underweight increases after treatment with the following:
- TBI for females.
- Radiation therapy to the abdomen for males.
- Certain types of chemotherapy (alkylating agents and anthracyclines).
The risk of being overweight or having obesity increases after treatment with the following:
- Radiation therapy to the brain.
- Surgery that damages the hypothalamus or pituitary gland, such as surgery to remove a craniopharyngioma brain tumor.
The following may also increase the risk of obesity:
- Being diagnosed with cancer between the ages of 5 and 9.
- Being female.
- Having growth hormone deficiency or low levels of the hormone leptin.
- Not doing enough physical activity to stay at a healthy body weight.
- Taking an antidepressant called paroxetine.
Childhood cancer survivors who get enough exercise and have a normal amount of anxiety have a lower risk of obesity.
Certain tests and procedures are used to diagnose a change in weight.
In addition to asking about your child’s personal and family health history and doing a physical exam, your child’s doctor may perform the following tests and procedures.
- Blood chemistry studies: A procedure in which a blood sample is checked to measure the amounts of certain substances, such as glucose, released into the blood by organs and tissues in the body. An unusual (higher or lower than normal) amount of a substance can be a sign of disease.
- Lipid profile studies: A procedure in which a blood sample is checked to measure the amounts of triglycerides, cholesterol, and low- and high-density lipoprotein cholesterol in the blood.
Being underweight, being overweight, or having obesity may be measured by weight, body mass index, percent of body fat, or size of the abdomen (belly fat).
Talk to your child's doctor about whether your child needs to have tests and procedures to check for signs of a change in weight. If tests are needed, find out how often they should be done.