Infant high grade gliomas appear clinically distinct from their counterparts in older children, indicating that histopathologic grading may not accurately reflect the biology of these tumors. We have collected 241 cases under 4 years of age, and carried out histological review, methylation profiling, custom panel and genome/exome sequencing. After excluding tumors representing other established entities or subgroups, we identified 130 cases to be part of an 'intrinsic' spectrum of disease specific to the infant population. These included those with targetable MAP-kinase alterations, and a large proportion of remaining cases harboring gene fusions targeting ALK (n=31), NTRK1/2/3 (n=21), ROS1 (n=9) and MET (n=4) as their driving alterations, with evidence of efficacy of targeted agents in the clinic. These data strongly supports the concept that infant gliomas require a change in diagnostic practice and management.

BackgroundChildhood and adult-onset craniopharyngioma is a rare embryogenic tumor of the sellar, suprasellar, and parasellar region. Survival rates are high; however, tumor location and treatment sequalae including endocrine deficits, visual impairment, metabolic complications, cognitive and psychosocial deficits can significantly impair patient’s quality of life. There is considerable controversy regarding the optimal management of craniopharyngiomas. Subtotal resection of the tumor followed by targeted irradiation to avoid further hypothalamic damage is currently indicated. Novel insights in the tumor’s molecular pathology present the possibility for targeted therapy possibly decreasing the rate and severity of treatment-associated morbidity.ConclusionsCraniopharyngioma should be seen as a chronic disease. To achieve optimal outcomes a multidisciplinary team of specialized neurosurgeons, neuro-radiologists, neuro-oncologists, pathologists and endocrinologists should be involved in the diagnosis, planning of the surgery, irradiation and long-term follow-up.

A population pharmacokinetic model developed in this study implies only a limited influence of genetic factors on the systemic disposition of MTX. Clearance is moderately reduced in patients with the MTHFR 677TT genotype. Genetic polymorphisms in the folate metabolic pathway and SLC19A1 were associated with HD-MTX toxicity.

The prediction of high-dose methotrexate (HD-MTX) toxicity is a key issue in the individualization of treatment in childhood acute lymphoblastic leukemia (ALL). Our aim was to evaluate the influence of MTX pathway polymorphisms on HD-MTX treatment outcome in children with ALL. In total, 167 children with ALL were genotyped for methylenetetrahydrofolate dehydrogenase (MTHFD1) 1958G > A, methylenetetrahydrofolate reductase (MTHFR) 677C > T and 1298A > C and thymidylate synthase (TYMS) 2R > 3R polymorphisms. The MTHFD1 1958A allele significantly reduced the odds of hepatotoxicity (adjusted p = 0.009), while the TYMS 3R allele significantly reduced the odds of leukocytopenia and thrombocytopenia (adjusted p = 0.005 and adjusted p = 0.002, respectively). MTHFR polymorphisms did not influence HD-MTX-related toxicity, but a significant effect of MTHFR 677C > T-TYMS 2R > 3R and MTHFD1 1958G > A-MTHFR 677C > T interactions on HD-MTX-related toxicity was observed. None of the investigated polymorphisms influenced survival. Our study suggests an important role of polymorphisms and gene-gene interactions within the folate pathway in HD-MTX-related toxicity in childhood ALL.