Efficacy of growth hormone replacement therapy in children with organic growth hormone deficiency after cranial irradiation.

We evaluated the growth response of 20 childhood cancer survivors who received growth hormone (GH) replacement therapy (0.3 mg/kg/week) for at least 12 months. In all subjects, GH deficiency was associated with cranial irradiation and was documented with growth charts, bone age, and somatomedin C levels; at least one GH stimulation test was available for 14 children. Pretreatment overall growth velocity was 3.3 +/- 0.5 cm/year (mean +/- SE) over a 3-year period. After GH replacement, growth velocity was 8.6 +/- 0.6 cm/year during the first year (n = 20), 7.2 +/- 0.5 cm/year during the second year (n = 17), 5.9 +/- 0.6 cm/year during the third year (n = 11), and (6.1 +/- 0.6 cm/year during the fourth year (n = 7). Growth response, tabulated by age at onset of GH replacement, was compared with the response in GH-naive children with idiopathic GH deficiency (data obtained through the Genentech Inc. National Cooperative Growth Study Summary, September 1991); the growth velocity fell within the range described for idiopathic GH deficiency adjusted for either chronological or bone age. We conclude that children with GH deficiency after cranial irradiation for neoplastic diseases respond to GH replacement therapy as well as children with idiopathic GH deficiency.