Effects of brain tumours and treatment on growth in childhood

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Find out how a brain tumour diagnosis and/or its treatment can impact your child’s growth and how the effects can be managed.

Key points

Children treated for brain tumours may experience impairment of growth.
Growth problems may be caused by the tumour itself, surgery, radiation or side effects of chemotherapy. They may also reflect other factors including timing of puberty and nutrition.
In some circumstances, growth hormone may be given to help maintain growth.
Research shows that growth hormone does not cause tumour cells to recur.

Introduction

Growth problems may occur among children with tumours located in or close to the pituitary gland (craniopharyngiomas, hypothalamic gliomas, germ cell tumours) and/or those who receive radiation therapy. As a result, for some children, growth and final height can be impacted.

Location of hypothalamus and pituitary gland — The hypothalamus and pituitary gland control the production of growth hormone. This hormone impacts how our bodies grow.

Causes, risk factors and prevalence

What causes growth problems?

There are several potential causes for growth problems.

The tumour itself, surgery, or radiation to the central part of the brain may damage the pituitary gland. This gland produces growth hormone, among other hormones. As a result of the tumour or treatment, the pituitary gland may not produce enough growth hormone, a condition called "growth hormone deficiency" (GHD). This is the most common hormonal side effect of brain tumour therapy.
Radiation therapy to the brain and spine can also impair the growth of bones in the skull and spine. This can result in a shorter spine and smaller skull or facial bones.
The effects of radiation are often more pronounced when given to younger children and when the dose to the spine is higher. In some cases, radiation causes early puberty. This may reduce final adult height because growth spurts of puberty may happen earlier, and growth ends sooner than is typical.
A poor appetite as a result of chemotherapy or other factors can result in inadequate nutrition and not enough calories. This is less common, but it can affect height.

Diagnosis

How will growth problems be assessed?

At each hospital visit, height and weight are recorded on a growth chart and are reviewed by the health-care team.

Being small does not by itself mean that a child has growth hormone deficiency (GHD). There are many factors to be considered. A review of the growth velocity (speed of growth), stage in puberty and occasionally, an X-ray of the wrist (called a "bone age"), will be compared to expected ranges for children of the same sex and age. Heights of both parents also help identify a child’s genetic potential.

Occasionally, a half-day visit to the hospital may be arranged to evaluate growth hormone levels in the blood. It is important to follow growth over the long-term because growth problems may not occur for several years after treatment.

Treatment

How can growth problems be managed?

For children who don’t produce adequate amounts of growth hormone (those with GHD), synthetic growth hormone may be prescribed. It is given by injection 6 days a week. It is effective in maintaining normal growth and growth spurts. It is most effective if it is started before puberty. The decision to use growth hormone should be made with the neuro-oncology treatment team and the endocrinologist, a doctor who specializes in treating hormone problems.
There is no treatment to increase height when the spine is affected by radiation. The spine is shortened by the effect of radiation and growth hormone will not help the spine grow.
For children who enter puberty earlier than is typical, early puberty can be treated with medications that pause puberty, and as a result may increase final adult height.
It is important to make sure that during treatment, as much as possible, children are well-nourished to help them grow.

Follow-up care

Can growth hormone cause the tumour to grow back?

In the past, there had been fears that growth hormone might cause tumour cells to grow back, because it stimulates cell growth. Many studies, including the U.S. Childhood Cancer Survivor Study have reassured us that growth hormone does not cause tumour cells to recur. There was no greater chance of a tumour growing back among people who received growth hormone treatment when compared with those who had no growth hormone treatment.

How will this affect your child’s future?

Children with brain tumours may experience impaired growth as a result of the tumour or radiation treatment. If a child is diagnosed with growth hormone deficiency, it can be treated. In addition to impacting growth, growth hormone deficiency may also be associated with decreased muscle strength, lower bone density and risk for heart disease. These often respond to growth hormone replacement. It remains unclear if individuals with GHD benefit from treatment with growth hormone after they have finished growing and into adulthood.

Resources

Children's Oncology Group Survivorship Follow-Up Guidelines: Growth Hormone Deficiency after Cancer Treatment

Last updated: January 10th 2022