Childhood Cancer Survivors and Endocrine Gland Dysfunction
Lillian R. Meacham, MD
Zoltan Antal, MD
Fady Hannah-Shmouni, MD
Kanakadurga Singer, M.A., M.D.
Growth Hormone Deficiency
Children and Bone Health
ThyCa: Thyroid Cancer Survivors Association
Childhood Cancer Survivors (CCS) and Endocrine Gland Dysfunction
Often, following cancer therapy, the endocrine system becomes deranged, manifesting with signs and symptoms that may mimic the recurrence of cancer itself. These symptoms are not limited to weight loss, hair loss, decreased appetite, decreased sexual function, breast enlargement, or tremors. The care of individuals who survived cancer, including children, adolescents and young adults is complex, and many patients should be cared for by endocrinologists and other physicians are familiar with important aspects of this care. The various therapies used to treat cancer can throw off the endocrine/hormonal system. Thus, it is critical to know the early and late endocrine symptoms that may develop and possible effects following cancer treatment in cancer survivors.
One of the most frequently affected endocrine organs in cancer survivors are the hypothalamus and pituitary glands. The hypothalamus produces and releases hormones and links the nervous and endocrine systems through the pituitary gland. One of the hormones that is produced in this region is growth hormone (GH). If survivors have too little of growth hormone (GH), then this can lead to health problems, including weight gain and growth failure in young survivors. Other hormones released by the pituitary gland can be affected as well, including fertility hormones such as LH and FSH, and cortisol producing hormone, called ACTH.
The endocrine conditions facing cancer survivors are growth failure, growth hormone deficiency, delayed or precocious puberty in children, secondary amenorrhea or loss of libido in sexually mature adolescents or adults, TSH deficiency, and ACTH deficiency. ACTH is the hormone responsible for cortisol production.
The causes of endocrine effects in survivors of cancer include surgery, chemotherapy, radiation, and effects of the cancer or tumor itself. These conditions are diagnosed based on specific clinical evidence, confirmatory blood tests and radiological evaluation. Most signs or symptoms are dependent on the affected endocrine gland:
Growth hormone deficiency from the pituitary gland:
- Growth deceleration or lack of growth acceleration with puberty in growing children - a decrease in growth rate or lack of pubertal growth spurt in pre-pubertal children
- Fatigue, abnormal fat deposition, body composition of fat and lean mass, elevated cholesterol in adults.
FSH and LH deficiency from the pituitary gland:
- Delayed or absent puberty as evidenced by lack of breast development in girls or testicular enlargement or penis enlargement in boys.
- Secondary amenorrhea (no periods) or loss of libido in sexually mature adults.
- Breast development in girls before age 8 years or testicular enlargement or penis enlargement in boys before ae 9 years.
- Fatigue, constipation, slow growth in growing children
- Fatigue, abdominal pain, weight loss, low blood sugar or low blood pressure particularly in times of acute illness
Important Management and Treatment Recommendations for Cancer Survivors with suspected endocrine dysfunction:
Cancer survivors are encouraged to ask their health care providers about the early or late endocrine developments of their cancer and/or therapy used for treatment. Based on the diagnosis that is made and the psychological and physical health of the patient, treatments can include thyroid hormone replacement, cortisol replacement, growth hormone therapy, and suppression or induction of puberty.
- Highlight the likelihood of endocrine disorders in CCS and how long of a latency period there can be between completion of treatment and the diagnosis of the endocrine disorder and it is recommended that a skilled doctor is closely monitoring growth and puberty since each of those can impact final height outcomes of a child.
- Stimulation testing – medical test to determine the way a child’s endocrine system responds to different types of hormones.
- Childhood cancer survivors should make sure that their doctor has a summary of their cancer treatment history and a list of conditions they are at risk for based on their treatment history.
Questions to Ask your Doctor
- Should any endocrine testing being done should be performed in any different way than for the general non-cancer survivor?
- Is there any medicine that can impact my child’s condition post cancer?
- What are the risk and the benefits of each treatment option?