Long-term follow-up of endocrine function among young children with newly diagnosed malignant central nervous system tumors treated with irradiation-avoiding regimens.

Background: The adverse effects of irradiation on endocrine function among patients with pediatric brain tumor are well documented. Intensive induction chemotherapy followed by marrow-ablative chemotherapy with autologous hematopoietic cell rescue (AuHCR) without central nervous system (CNS) irradiation has demonstrated efficacy in a proportion of very young children with some malignant CNS tumors. This study assessed the long-term endocrine function of young children following chemotherapy-only treatment regimens.

Procedures: A retrospective chart review was performed on 99 patients under 6 years of age with malignant brain tumors newly diagnosed between May 1991 and October 2010 treated with irradiation-avoiding strategies. Thirty patients survived post-AuHCR without cranial irradiation for a mean of 8.1 years (range 3.0-22.25 years). The patient cohort included 18 males and 12 females (mean age at AuHCR of 2.5 years, range 0.8-5.1 years).

Results: All 30 surviving patients had documented normal age-related thyroid function, insulin-like growth factor binding protein 3 (IGF-BP3), prolactin, testosterone, and estradiol levels. Insulin-like growth factor 1 age-related levels were abnormal in one child with normal height. Ninety-seven percent of patients had normal cortisol levels, while follicle-stimulating hormone and LH levels among females were normal in 83% and 92%, respectively, and in 100% of males. Growth charts demonstrated age-associated growth within 2 standard deviations of the mean in 67% of patients. Of 10 patients (33%) with short stature, 6 had proportional diminutions in both height and weight.

Conclusions: These findings demonstrate that the use of relatively brief, intensive chemotherapy regimens including marrow-ablative chemotherapy with AuHCR results in fewer endocrine sequelae than treatment schemes utilizing CNS irradiation.