Growth and growth hormone secretion after treatment for childhood non-Hodgkin's lymphoma

The aim of this study was to evaluate the growth and growth hormone (GH) secretion, as assessed by the rate and pattern of secretion, in patients in remission from non-Hodgkin's lymphoma (NHL) who had been treated with corticosteroids and intense chemotherapy. None of the patients had received cranial irradiation. Twelve children were investigated yearly by taking 24-hour GH profiles starting 1 year from the time of diagnosis. The mean age at onset of the disease was 7.5 years. Another 12 young adults were studied in a cross-sectional manner 4.1-21.3 years (mean, 9.0 years) after diagnosis of NHL. The mean age at onset of the disease was 10.7 years. The median height velocity was significantly decreased during the 1st year following diagnosis (standard deviation scores [SDS] -0.15, P < .001), especially during the first 3 months (SDS -0.75, P < .001) when the most intense treatment was given. During the 2nd year height velocity was still somewhat reduced (SDS -0.13, P < .001). However, there was no reduction in final attained height. Spontaneous GH secretion, in terms of both secretory rate and pulsatile pattern, was evaluated by measuring integrated GH concentrations in 20-minute blood samples collected over a 24-hour period. The plasma GH concentrations were transformed into GH secretion rates by means of a deconvolution technique. Fourier time series analysis was applied to determine possible disturbances of rhythmicity of the GH secretion. The GH secretion rate and the pulsatile pattern of secretion in the NHL patients were similar to those of the reference population of pubertal matched healthy controls. There was no influence of the age at diagnosis or of the time from diagnosis of NHL on the GH secretion rate. Growth impairment in children with a malignant disease treated only with steroids and chemotherapy is therefore probably not caused by disturbed GH secretion, but rather by direct interference with bone growth of the cytotoxic drugs used. There was no significant influence on weight gain during the treatment period so an indirect effect of chemotherapy on bone growth through interference with adequate nutrition seems unlikely. However, GH secretion was not evaluated during the period of growth retardation, and therefore a transient deficiency was not excluded.