Neuropsychological outcomes on Head Start III: a prospective, multi-institutional clinical trial for young children diagnosed with malignant brain tumors

Background. Current pediatric brain tumor treatment focuses on titrating toxicity based on risk factors while simultaneously improving survivorship. The Head Start (HS) protocols I to IV (1991-present) use high-dose chemotherapy (HDCTx) with an aim of reducing or eliminating cranial irradiation in very young children, the most vulnerable to its effects. Methods. We examined estimated Full Scale IQ, overall Adaptive Functioning, Working Memory, Processing Speed, and Verbal and Nonverbal Memory outcome data for 43 HS III patients diagnosed between ages 2 months and 7 years from 15 institutions in the United States and Canada. Results. At a mean of 5.12 years postdiagnosis, the HS III patients performed within the average to low-average ranges across these variables; however, individual variability was noted with scores ranging from superior to impaired, and the sample as a whole performed lower than age expectations. Performance did not significantly differ by sex or ethnicity, diagnosis, or for those treated with an intravenous methotrexate dose of 400 mg/kg vs 270 mg/kg. Additionally, performance did not significantly differ by age at diagnosis or length of follow-up. Conclusions. The results, indicating overall average to low-average neurocognitive functioning, are encouraging, though significant individual variability was noted. Those who were younger at diagnosis, received more intensive methotrexate, and were further out from treatment were not at significantly increased risk of cognitive decline within our sample, suggesting a strategy of using HDCTx and autologous hematopoietic progenitor cell rescue to reduce or eliminate irradiation may allow for continued CNS development in young children treated for a brain tumor.