Some people who were treated for cancer during childhood develop endocrine (hormone) problems as a result of changes to the endocrine system.
The endocrine system is a group of glands that regulate many body functions including growth, puberty, energy level, urine production, and stress response. Glands of the endocrine system include the pituitary, hypothalamus, thyroid, adrenals, pancreas, ovaries (in females) and testes (in males). The hypothalamus and pituitary are sometimes called the “master glands” because they control many of the other glands in the endocrine system. Unfortunately, some treatments given for children’s cancer can damage the endocrine system, resulting in a variety of problems.
Hormones
Hormones are chemical messengers that carry information from the endocrine glands through the bloodstream to the body’s cells. The endocrine system makes many hormones (such as growth hormone, sex hormones, adrenal and thyroid hormones) that work together to maintain specific bodily functions.
Central Adrenal Insufficiency
Central adrenal insufficiency is caused by a deficiency of the pituitary hormone known as Adrenocorticotropic Hormone (ACTH). The adrenal glands (located on top of the kidneys) are stimulated by ACTH to produce a hormone known as cortisol. If the pituitary gland doesn’t make enough ACTH, then cortisol will not be made by the adrenal gland. Cortisol is important for health because it helps to keep the blood sugar at a normal level and helps the body deal with physical stress, such as fevers or injuries.
Risk Factors for Central Adrenal Insufficiency
Radiation to the brain, especially in doses of 30 Gy (3000 cGy/rads) or higher, including the following fields:
- Cranial (whole brain)
- Craniospinal
- Nasopharyngeal (nose and throat)
- Oropharyngeal (mouth and throat)
- Orbital
- Eye
- Ear
- Infratemporal (midfacial area behind the cheekbones)
- Total body irradiation (TBI)
Surgical removal of the pituitary gland also leads to central adrenal insufficiency.
Symptoms of Central Adrenal Insufficiency
Under normal circumstances, there may be no symptoms at all, or there may be mild symptoms, such as fatigue, weakness, poor appetite, or dizziness. However, under stressful circumstances, such as fever, infection, surgery, or injury, symptoms may become severe and may include vomiting, diarrhea, low blood sugar, and dehydration.
Recommended Screening
People who had radiation in a dose of 30 Gy or higher to the central area of the brain (hypothalamic-pituitary axis), or people who are having symptoms suggestive of central adrenal insufficiency, should have a blood test done to check their cortisol level. This test should be done at least once following the completion of cancer treatment (and is often done at least 2 years following completion of therapy). This test is usually done first thing in the morning because cortisol levels vary throughout the day and is usually highest early in the morning.
If your morning cortisol level is abnormal, your healthcare provider will likely refer you to an endocrinologist (doctor who specializes in hormone problems). The endocrinologist will do more specific tests to evaluate the problem.
Treating Central Adrenal Insufficiency
Central adrenal insufficiency is treated with hydrocortisone, a medication that is taken by mouth every day on a regular schedule. In times of increased stress, such as illness or surgery, the dose of hydrocortisone is increased and can be administered by injection if necessary. People with central adrenal insufficiency should wear a medical alert bracelet so that in case of accident or sudden illness, emergency medical professionals are aware of special health needs.