No abstract

Background Childhood cancer survivors treated with cranial or total body irradiation (TBI) are at risk for growth hormone deficiency (GHD). Recombinant growth hormone (rhGH) therapy is associated with slipped capital femoral epiphysis (SCFE). We compared the incidence of SCFE after TBI versus cranial irradiation (CI) in childhood cancer survivors treated with rhGH. Procedure Retrospective cohort study (1980–2010) of 119 survivors treated with rhGH for irradiation-induced GHD (56 TBI; 63 CI). SCFE incidence rates were compared in CI and TBI recipients, and compared with national registry SCFE rates in children treated with rhGH for idiopathic GHD. Results Median survivor follow-up since rhGH initiation was 4.8 (range 0.2–18.3) years. SCFE was diagnosed in 10 subjects post-TBI and none after CI (P < 0.001). All 10 subjects had atypical valgus SCFE, and 7 were bilateral at presentation. Within TBI recipients, age at cancer diagnosis, sex, race, underlying malignancy, age at radiation, and age at initiation of rhGH did not differ significantly between those with versus without SCFE. The mean (SD) age at SCFE diagnosis was 12.3 (2.7) years and median duration of rhGH therapy to SCFE was 1.8 years. The SCFE incidence rate after TBI exposure was 35.9 per 1,000 person years, representing a 211-fold greater rate than reported in children treated with rhGH for idiopathic GH deficiency. Conclusions The markedly greater SCFE incidence rate in childhood cancer survivors with TBI-associated GHD, compared with rates in children with idiopathic GHD, suggests that cancer treatment effects to the proximal femoral physis may contribute to SCFE.

In the last decade, 13-cis-retinoic acid (13-cis-RA) has been added to the treatment of patients with high-risk neuroblastoma. In survivors of neuroblastoma, short stature is consistently observed. Causes include growth hormone deficiency and poor growth of irradiated long bones. Within the survivorship program at CHOP, we have observed that a number of these patients also have advanced bone ages. Children treated with 13-cis-RA are at risk for advanced bone age that may dramatically impact their linear growth. Ongoing evaluation is necessary to examine the effect of 13-cis-RA on final adult height and to inform clinical practice in this cohort.

No abstract