Hypothalamic-pituitary function following childhood brain tumors: Analysis of prospective annual endocrine screening

Background Outcomes for childhood brain tumors are now associated with a five-year survival rate of 75%. Endocrine effects of brain tumors are common, occurring in 43% of patients by 10 years from tumor diagnosis. Optimal timing of screening for endocrinopathies remains undefined. We aim to identify incidence and timing of endocrinopathies following brain tumor diagnosis, to better refine screening guidelines. Methods Retrospective chart review of patients referred to our hospital's neuro-oncology clinic for evaluation and treatment of brain tumors. Inclusion criteria were a positive history for brain tumor diagnosis and evaluation at our center. Data collection included demographics, tumor diagnosis, tumor therapy, and endocrinopathy diagnosis and timing. Laboratory data and clinical documentation were reviewed. Results Four hundred nineteen subjects were included for analysis. Tumor locations included supratentorial 158 (38%), posterior fossa 145 (35%), suprasellar 96 (23%), and upper spinal cord 20 (5%). Only 61% had undergone endocrine screening. Forty-five percent of screened patients had endocrinopathies. Endocrinopathy diagnosis typically occurred within six years after tumor diagnosis. Tumor recurrence and repeated therapies increased the risk for endocrinopathies within the subsequent six years after tumor therapy. Higher rates of endocrinopathies were identified in patients who had received cranial irradiation for posterior fossa, supratentorial, or suprasellar tumors. Conclusion Endocrine screening should occur in childhood brain tumor survivors, particularly those who have received irradiation. Our study suggests that in children with brain tumors, the highest yield for finding a pituitary deficiency is within the first six years after tumor diagnosis and treatment. Screening should continue annually beyond six years, but with special attention in the subsequent six years after therapy for tumor recurrence. Prospective screening and endocrinology referral should be implemented in childhood brain tumor survivors.