Effects of treatments on gonadal function in long-term survivors of pediatric hematologic malignancies: A cohort study

Background: Potentially gonadotoxic protocols are currently used for the treatment of childhood hematologic malignancies. This study aims to evaluate the prevalence of gonadal dysfunction and the most important associated risk factors in a cohort of hematologic malignancy survivors. Procedure: We considered all patients referred to our long-term follow-up clinic for childhood cancer survivors, between November 2001 and December 2017. Inclusion criteria were: (a) previous diagnosis of hematologic malignancy; (b) age at hematologic malignancy diagnosis < 18 years; (c) at least five years after the end of anticancer treatments; (d) at least one evaluation of gonadal function after the 18th birthday. Patients diagnosed before January 1, 1990, were excluded. Results: Three hundred twenty-seven survivors (males = 196) were included. Isolated spermatogenesis damage was found in 58/196 (29.6%) of males, whereas 18/196 (9.2%) had Leydig cell failure. In females, 35/131 (26.7%) experienced premature ovarian insufficiency. In both sexes, abdominopelvic irradiation and hematopoietic stem cell transplantation were strongly associated with the risk of gonadal dysfunction. For every 1000 mg/m2 increase in cyclophosphamide-equivalent dose exposure, the risk of spermatogenesis damage increased 1.52-fold and that of Leydig cell failure increased 1.34-fold, whereas the risk of premature ovarian insufficiency increased 1.80-fold. About 30% of those males who developed Leydig cell failure did so more than five years after the end of treatments. Conclusions: Gonadal dysfunction is still a significant late effect of therapies for pediatric hematologic malignancies. In males, the reevaluation of Leydig cell function may be useful even several years after the exposure to gonadotoxic treatments.