Growth hormone function and treatment following bone marrow transplant for neuroblastoma

Abstract

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.