Pediatric Cancers and Brain Tumors in Adolescents and Young Adults.

Embryonal tumors classically occur in young children, some principally within the first year of life. Prospective national and international clinical trials during recent decades have brought about progressive improvements in survival, and associated biological studies have advanced our understanding of tumor biology, in some cases allowing biological tumor characteristics to be harnessed for therapeutic benefit. Embryonal tumors continue to occur, albeit less commonly, during childhood, adolescence and throughout adulthood. These tumors are less well understood, usually not managed according to standardized protocols and rarely included in clinical trials. Survival outcomes are generally poorer than their childhood equivalents. We present here a summary of the published literature on embryonal tumors that present ectopically during adolescence and adulthood. We show that for some tumors protocol-driven treatment, supported by accurate and complete diagnostics and staging, can result in equivalent outcomes to those seen during childhood. We make the case that clinical trial eligibility criteria should be disease-based rather than age-based, and support improvements in dialogue between children's and adults' cancer clinicians to improve outcomes for these rare tumors.