Childhood Cancer Survivors at Risk for Hormone Deficiencies After Radiotherapy

February 19, 2015

A new study finds that childhood cancer survivors are at risk for pituitary hormone deficiencies after radiotherapy treatment to the head.

After brain radiation for treatment of childhood cancer, survivors are at risk for pituitary hormone deficiencies, a new study finds. Researchers found that anterior pituitary deficits are common years after radiotherapy to the head. These deficiencies can cause poor health in adults who had a childhood cancer. The results were published in the Journal of Clinical Oncology.

The study found that more than half (51.4%) of childhood cancer survivors had a deficiency in at least one hormone; 10.9% had more than one.

The hormones included in the analysis were all pituitary gland hormones-growth hormone, luteinizing hormone/follicle-stimulating hormone, thyroid-stimulating hormone, and adrenocorticotropic hormone.

The most common deficiencies were in the growth hormone and gonadotropin-fertility and reproduction hormones. Survivors with these deficiencies were more likely to have early death, poor fitness, muscle weakness, and heart disease risk factors.

Younger age during radiotherapy and a higher dose of radiation was associated with a greater risk for pituitary hormone deficiencies later in life.

Wassim Chemaitilly, MD, of the department of pediatric medicine and the division of endocrinology at St. Jude Children’s Research Hospital in Memphis, and colleagues analyzed retrospective data from 748 participants in the St. Jude Lifetime Cohort (SJLIFE) Study to assess the late-onset endocrine effects of radiotherapy and to provide clinical guidance for screening of hypopituitarism and other health concerns. All participants were diagnosed and treated for childhood leukemia, lymphoma, and brain and other cancers, and had brain radiotherapy. The majority (72.6%) of study participants had leukemia.

Currently, brain radiation continues to be used for pediatric brain tumors.

Three hundred and ninety-four (52.7%) participants were male. The mean age of the cohort was 34.2 years. The participants were an average of 27 years from the diagnosis of their childhood cancer.

Of the survivor participants, 46.5% had a growth hormone deficiency, 10.8% had a luteinizing hormone/follicle-stimulating hormone deficiency, 7.5% had a thyroid-stimulating hormone deficiency, and 4% had an adrenocorticotropic hormone deficiency.

An untreated luteinizing hormone/follicle-stimulating hormone deficiency was associated with abdominal obesity, hypertension, dyslipidemia, low energy expenditure, and slow walking. A deficiency in untreated growth hormone is linked to abdominal obesity, low muscle mass, low energy expenditure, muscle weakness, and poor exercise tolerance.

“This study provides much needed long-term follow-up data and shows that the risk of pituitary problems follows these survivors into adulthood,” said Chemaitilly in a statement. “The findings also underscore the need for the nation’s growing population of childhood cancer survivors to get recommended health screenings, and the challenges they face in trying to navigate the healthcare system and follow that advice.”

Currently, guidelines from the Children’s Oncology Group recommend that those who were treated with brain radiation for a childhood cancer have annual pituitary function assessments. St. Jude is working on a pilot program to facilitate a switch from pediatric to adult clinical care for childhood cancer survivors at risk for endocrine issues.