Impact of Serum Insulin-Like Growth Factor 1 on Hematopoietic Stem Cell Transplantation Outcome in Pediatric Cancer Patients

Abstract

Hematopoietic stem cell transplantation (HSCT) is associated with severe medical complications and variable outcomes depending on the recipient's disease stage and health condition. Biomarkers predicting outcome may have therapeutic relevance in pediatric cancer care. Insulin-like growth factor 1 (IGF-1), a mitogenic and anabolic peptide hormone expressed in almost all tissues, is the major growth factor in childhood. Decreased IGF-1 concentration in conditions that cause catabolic metabolism may reflect a patient's degree of physical robustness and serve as a predictive biomarker for transplantation outcome. We evaluated the impact of pretransplantation serum IGF-1 level on both survival and adverse events in 587 pediatric cancer patients who underwent autologous or allogeneic HSCT between 1987 and 2014 at the University Children's Hospital Tübingen. Survival probabilities of the entire cohort and of defined subgroups according to pretransplantation serum IGF-1 level were estimated using the Kaplan-Meier method. The mean pretransplantation IGF-1 level (n = 498) was low: -1.67 SDS (SD, 1.54). Completeness of follow-up was 96% at 3 years post-HSCT and 83% at 10 years. Overall survival (OS) at 10 years was 44.8% (95% confidence interval, 40.6% to 48.9%). Decreasing IGF-1 SDS was associated with significant increases in transplantation-related mortality (P = .027), sinusoidal obstruction syndrome (quartiles 4 to 1: 3%, 1%, 12%, and 12%; P < .001), and thrombotic microangiopathy (quartiles 4 to 1: 0%, 0%, 2%, and 5%; P = .004). Compared with patients in IGF-1 deciles 2 to 10, patients in IGF-1 decile 1 had significantly poorer outcome (P = .042) with lower median survival (12 months versus 68 months) and 10-year OS (37% versus 52%). This retrospective study suggests that pretransplantation serum IGF-1 level has utility as a predictor of survival and selected vascular adverse events that may have diagnostic and therapeutic relevance in pediatric cancer care.