Objective: To evaluate the effect of chemotherapy on growth and growth hormone (GH) secretion.
Methods: We analyzed growth and GH secretion in 60 children in complete remission after treatment by chemotherapy and surgery for malignant solid tumors. None of them received cranial radiotherapy. Growth hormone reserve was assessed by at least two stimulation tests (clonidine, L-dopa, growth hormone-releasing hormone). In 12 children the reserve of GH pretreatment was also evaluated.
Results: Growth hormone deficiency (GHD) was observed in 27 of 60 patients (45%). At diagnosis, mean standing height was +0.23 +/- 0.11 standard deviation score (SDS) in the GHD group and +0.16 +/- 0.10 SDS in the non-GHD group. After chemotherapy, mean standing height in the GHD group was -0.28 +/- 0.15 SDS and -0.14 +/- 0.11 in the non-GHD group (p < 0.05), and the growth rate was +0.13 +/- 0.07 SDS in the GHD group and +0.22 +/- 0.18 SDS in the non-GHD group. For a mean follow-up of 30 months, the mean standing height was -0.46 +/- 0.29 SDS in the GHD group and -0.24 +/- 0.16 SDS for the non-GHD group (p < 0.05), and the growth rate was -0.27 +/- 0.19 SDS in the GHD group and -0.16 +/- 0.12 SDS in the non-GHD group (p < 0.05). The GH response to clonidine was significantly less than that found with the other stimuli. There was correlation between the dose intensity of some drugs and the subsequent GH response to stimulation tests. The GHD group was found to have received significantly higher doses of actinomycin D than the non-GHD group (p < 0.05). Growth impairment and GHD were not found to be correlated with duration of treatment and follow-up, tumor type, sex, or age.
Conclusions: Chemotherapy as the sole form of treatment in children with cancer interferes with growth. The observed impairment of growth depends, at least in part, on a GHD related to chemotherapy. The growth rate in conjunction with the GH response to clonidine provides a sensitive measure of GHD associated with chemotherapy.