Hormones
Head radiation, total body irradiation, high-dose chemotherapy and transplant can affect the glands that make hormones. This topic explains which hormones can change, the signs and the treatment.
01Short answer
02Simple explanation
Hormones are messenger substances.
The “conductor” is the pituitary gland.
Risks: head radiation, total body irradiation, alkylating medicines.
In children, growth and puberty are monitored.
Deficiency is corrected with replacement therapy.
03Scientific explanation
Pituitary: under the Endocrine Society 2018 guideline, head radiation of 18 Gy or more raises the risk of growth hormone deficiency; risk rises with dose and time since radiation.
Sex glands: high-dose cyclophosphamide, busulfan and total body irradiation can affect ovarian and testicular function; women have a higher risk of early menopause (MedlinePlus).
Children: the COG recommends checking height, weight and sexual development every year and referring to an endocrinologist when needed.
Steroids: long-term corticosteroids can temporarily suppress the adrenal glands’ own hormone production; the medicine must not be stopped suddenly.
04What happens in the body?
What are hormones?
Substances made by glands and carried by the blood around the whole body. They control growth, energy, sexual function, mood and bones.
The pituitary — the conductor
A small gland at the base of the brain “instructs” other glands. If head radiation has affected it, growth hormone or other hormones may fall.
What to watch for in children
Slow growth, and puberty starting very late or very early. Regular height measurements and doctor checks show this in time.
What to watch for in adults
In women, periods stopping or becoming irregular, and hot flushes; in men, lower sex drive, tiredness and loss of muscle strength. These may be low testosterone or oestrogen.
Treatment
If a deficiency is found, an endocrinologist prescribes hormone replacement: growth hormone, oestrogen/progesterone, testosterone and others. This protects bones, heart and quality of life.
When to call your doctor
Worrying signs — fever, bleeding, new pain, breathlessness — should be reported to your doctor between visits too. Getting in touch early is always better than waiting.
05Hormonal balance
Steps of hormone follow-up.
06Hormone risks (simplified)
| Treatment | Possible effect | Check |
|---|---|---|
| Head radiation | Growth hormone deficiency, early puberty | Height, IGF-1, endocrinologist |
| Total body irradiation | Sex gland and thyroid failure | Hormone tests |
| Alkylating medicines | Early menopause, low testosterone | FSH, LH, oestradiol, testosterone |
| Long-term steroids | Adrenal suppression | Doctor’s assessment |
| Transplant | Several hormones | Regular follow-up |
* The testing plan is individual.
07Key terms
- Hormone
- A messenger substance released by a gland into the blood.
- Pituitary
- The brain gland that controls hormones.
- Endocrinologist
- A doctor for hormone disorders.
- Early menopause
- Ovarian function stopping before age 40.
- Hypogonadism
- Low sex hormones.
- Replacement therapy
- Giving a missing hormone as medicine.
08Key points
- Hormones control many functions.
- Head and total body radiation raise risk.
- Growth is monitored in children.
- Adults should watch for signs.
- Replacement therapy is effective.
- Never take hormones on your own.
09Frequently asked questions
My periods have not come back. Is that normal?
They can be delayed for months after treatment; if it lasts, hormone tests and medical advice are needed.
Is growth hormone safe?
Under an endocrinologist’s supervision; the decision is made individually together with your haematologist.
Do hormone problems affect fertility?
They can; see the fertility topics.
When should I see an endocrinologist?
If you are at risk — as planned; if you have signs — promptly.
Does this information replace medical advice?
No. This is general education; only your treating doctor can assess your situation.
10Questions for your doctor
Take these questions to your appointment. The ones you save are collected on the “My questions” page and stay on this device only.
My periods have not come back. Is that normal?
Is growth hormone safe?
Do hormone problems affect fertility?
When should I see an endocrinologist?
Does this information replace medical advice?
12Sources
- Journal of Clinical Endocrinology & Metabolism, 2018. Sklar CA et al. Hypothalamic–Pituitary and Growth Disorders in Survivors of Childhood Cancer: An Endocrine Society Clinical Practice Guideline
- Children's Oncology Group. Long-Term Follow-Up Guidelines for Survivors of Childhood, Adolescent and Young Adult Cancers
- National Cancer Institute (NCI). Late Effects of Treatment for Childhood Cancer (PDQ®)–Patient Version
- MedlinePlus (U.S. National Library of Medicine). Growth Hormone Deficiency
- MedlinePlus (U.S. National Library of Medicine). Hypopituitarism
- MedlinePlus (U.S. National Library of Medicine). Premature ovarian failure
- MedlinePlus (U.S. National Library of Medicine). Hypogonadism
- National Cancer Institute (NCI). Follow-Up Medical Care
- National Cancer Institute (NCI). Cancer Survivorship
- Cancer.Net (ASCO). Follow-Up Care After Cancer Treatment
- Leukemia & Lymphoma Society (LLS). Long-Term and Late Effects of Treatment