Hormonal Late Effects
Depending on where a child’s brain tumor was located and what kind of treatment they received, they may experience late effects that impact their hormones.
Hormones are chemicals that are made in a gland in one part of the body and travel to other parts of the body as a signal to cells and organs to start or stop their work. The brain contains two glands that help control hormones, the pituitary gland and hypothalamus.
Pediatric brain tumor patients and survivors often experience hormone problems (also called endocrine problems) because of how their tumor and the treatments they received affect these glands.
About the pituitary gland and hypothalamus
The pituitary gland is located at the base of the skull. It is sometimes called the “master gland” because it releases hormones into the bloodstream to control glands in other parts of the body that make hormones.
The hypothalamus is at the base of the brain above the pituitary gland. Nerve cells in the hypothalamus make several different hormones that control specific pituitary hormones.
The hormones the hypothalamus and pituitary gland control affect most body functions, including energy levels, metabolism, and body temperate, how we sleep and grow, and thyroid and kidney functions. The pituitary gland also makes important hormones that affect puberty and reproduction.
Why brain tumor survivors can have hormone problems
When a brain tumor grows close to the pituitary gland or hypothalamus, it can cause problems with how these glands work. Children and teens with a tumor in this location may start having hormone problems even before their brain tumor is diagnosed.
Treatments like radiation, chemotherapy, and surgery can also damage the pituitary gland and hypothalamus and cause hormone problems in brain tumor survivors.
Brain tumor survivors who have hormone problems can see a doctor who is an expert in hormone treatment called an endocrinologist. Endocrinologists will order blood tests or stimulation tests to find out whether a hormone level is low or high. Patients with low hormone levels can often replace the missing hormones with a pill, patch, or injection. When hormone problems are treated properly, brain tumor survivors can often have a normal quality of life.
Types of Hormonal Late Effects and What to Do
Growth Hormone Problems
The pituitary gland and hypothalamus produce the growth hormone that which tells bones to grow longer. Radiation may damage the way these glands work. Children treated at a younger age or with higher doses of radiation to the area where these glands are located have a larger chance of not having enough growth hormone.
What You Can Do About Growth Hormone Problems
If your child got radiation before going through puberty, their growth must be watched closely. The endocrinologist should be part of their healthcare team and will watch their growth. If your child doesn’t have enough growth hormone, one option is to get growth hormone shots.
Thyroid Gland Problems
The thyroid is a gland in the base of the neck. Radiation to the thyroid can cause it to become underactive, or in some people, overactive. Radiation to the thyroid gland can also cause the development of lumps in the thyroid called nodules that sometimes become cancerous.
What You Can Do About Thryoid Gland Problems
Survivors should have a blood test every year to see if thyroid hormones are at the right level. The thyroid gland should be looked at by a doctor or nurse at least once per year to make sure it is a normal size and that there are no nodules that need to be checked out.
Problems with Fertility or Sexual Function
Some types of chemotherapy and radiation can affect survivors’ fertility and sexual function, including starting puberty or menopause early and a loss of sexual desire later in life. Starting early puberty can also stop a child from growing taller
What You Can Do About Problems with Fertility or Sexual Function
Sex hormone levels are often checked in girls at age 13 and in boys at age 14. It is important for your child to see an endocrinologist at the first signs of puberty, especially if they are younger than 10 years old.
Talk with your child’s healthcare team about what their risks are for infertility and sexual problems. Talking to an endocrinologist or fertility specialist as early as possible gives survivors the best understanding of their options in having a family.
As girls get older, they should share their complete history with their gynecologist.