Growth hormone function and treatment following bone marrow transplant for neuroblastoma

Previously, we reported that 26 children with stage III or IV neuroblastoma (NBL) treated with BMT grew poorly post-BMT and significantly worse than a comparison group of hematologic BMT patients. Furthermore, unlike the hematologic patients, there was no apparent catch-up growth. Six of these previously reported long-term (> 2 years) NBL patients surviving BMT were evaluated with growth hormone (GH) provocative testing, frequent (every 20 min) overnight GH sampling and IGF-1 determinations. Three of 6 patients were GH deficient based on subnormal responses to provocative stimuli and subnormal pooled 12 h GH values. Only one child had completely normal GH testing and his growth was normal. Four patients were tested with recombinant GH for a period of 12-21 months. Three patients demonstrated an improvement in their growth velocity on therapy. However, the overall response to GH treatment was significantly less than the growth response in children who are GH-deficient due to causes other than BMT. In summary, GH deficiency may be a frequent complication of BMT treatment of NBL. It also appears that the BMT treatment protocol employing total body irradiation and high-dose melphalan may induce GH resistance.