Children treated for brain tumours are more likely to reach full adult height if they are given growth hormone replacement at an early stage, research has found.
Radiotherapy can stunt growth
Brain tumours can be treated with radiation - but this can stunt growth by reducing the growth hormone in a child.
Specialists at the Christie Hospital in Manchester conducted a 25-year study into how best to treat these children.
They found that the younger a child was when they were treated for a brain tumour, the worse their chances of reaching full adult height.
They also found that older children were more likely to receive growth hormone treatment rapidly following cancer treatment - presumably because they had less time left to grow.
Lead researcher Professor Steve Shalet said: "The study looked at whether the final height of these children is improved if growth hormone is given when they are very young, in addition to giving it when they are teenagers.
Professor Shalet led the research
"We found that earlier growth hormone replacement, plus improved schedules of administering the growth hormone, does improve final height among childhood brain tumour survivors."
The study also found that children who received radiation treatment later over the 25-year period of the study were started on growth hormone therapy earlier.
This change may explain the improvement in final height in more recent years.
Dr Lesley Walker, director of cancer information at Cancer Research UK, said brain tumours accounted for approximately a quarter of childhood cancers, with nearly 300 children affected each year in the UK.
"Treating childhood brain tumours is difficult as some of the side-effects of treatment can last well into adult life. One such side-effect is lack of growth which can occur as a result of radiotherapy.
"Normally, growth hormone is secreted by the pituitary gland at the base of the brain, but if radiotherapy is directed towards this area then growth hormone levels can be reduced.
"The research reflects important progress in treatment for childhood brain tumours and will contribute to a better quality of life for patients long after treatment has ended."
The research is published in the Journal of Clinical Endocrinology & Metabolism.