The treatment of high grade gliomas and diffuse intrinsic pontine tumors of childhood and adolescence: a historical - and futuristic - perspective.

Pediatric high grade gliomas represent a heterogeneous group of tumors with poor prognoses despite the use of multimodal treatment. Very little progress has been made over the past decades in identifying efficacious therapeutic modalities against both high grade gliomas and diffuse brainstem gliomas in children. The degree of surgical resection is the most important clinical prognostic factor for children with high grade gliomas, and a complete resection should be attempted whenever feasible. The role of radiation therapy in the treatment of older children with high grade gliomas and diffuse brain stem gliomas is undisputed; however the benefit of using radiation for patients less than 6 years of age (with high grade gliomas) might be questionable. Despite the absence of solid evidence to support its use, chemotherapy is routinely used against these tumors. Currently temozolomide is being investigated due to its activity in adult trials and based on preliminary data regarding recurrent disease. A small subgroup of patients can be successfully treated with high dose chemotherapy followed by autologous stem cell rescue. Early trials using this modality in the past had been associated with high morbidity and mortality. High dose chemotherapy with autologous stem cell rescue in selected patients with minimal residual disease, angiogenesis inhibitors, radiosensitizers and other biological modifiers are being currently investigated in phase I/II trials.