High-grade glioma in children under 5 years of age: a chemotherapy only approach with the BBSFOP protocol. Eur J Cancer. 2006;42:2939-2945. [PMID: 16962317 DOI: 10.1016/j.ejca.2006.06.021]

Pediatric high-grade gliomas and diffuse intrinsic pontine gliomas

Pediatric high-grade gliomas represent approximately 10% of all pediatric brain tumors. Similar to adult high-grade gliomas, they behave very aggressively, and these children have a very poor prognosis despite a variety of therapies that include chemotherapy and radiotherapy. In this review, we present an overview of both pediatric high-grade gliomas and diffuse intrinsic pontine gliomas with a focus on their epidemiology, etiology, presentation, prognostic factors, biology, treatment modalities, outcomes, and future research directions.

Clinical and epidemiological characteristics of pediatric gliosarcomas

Gliosarcoma (GS) is a glioblastoma with a sarcomatous component that is presumed to be a metaplastic differentiation of glioma cells. We studied the clinical relevance of this histological glioblastoma subentity within the pediatric population. We obtained patient data from the German HIT-GBM database, which contains clinical data for more than 600 pediatric patients with centrally reviewed high-grade gliomas. By applying defined inclusion criteria (diagnosis of GS proven by central neuropathological review; patient age 0 to 21 years), four patients were identified. In addition, after a review of the English medical scientific literature, 19 additional cases were found. The relative frequency of GS in the German HIT-GBM database was only 1.9%. In the whole series of 23 pediatric GS patients, including previously reported cases, the male-to-female-ratio was 1.2:1. GS was found in all pediatric age groups with a median age of 11 years, but there was an unexpectedly high accumulation in infants (6 of 23 <3 years of age, 26%). GS showed a strong predilection of the cerebral hemispheres (22 out of 23 cases). Increased intracranial pressure was the leading symptom of a short clinical history with a median duration of 0.7 month. Interestingly, six patients (26%) were reported with a history of cranial radiotherapy prior to GS diagnosis. In 60% of the GS patients in our series, gross total resection was achieved. Median overall (OS) and event-free survivals (EFS) of the total cohort were 12.1 and 9.8 months, respectively. In conclusion, GS is a very rare tumor entity in children. Literature review suggests a relatively higher incidence in infants and in patients with a previous history of radiotherapy.

Current treatment approaches for infants with malignant central nervous system tumors

The management of brain tumors in very young children remains a challenge for neuro-oncologists in large part because of the greater vulnerability of the developing brain to treatment-related toxicity. Nearly three decades of infant brain tumor clinical trials have led to significant progress in the delineation of prognostic factors and improvements in outcome. Innovative strategies that employ high-dose chemotherapy, intrathecal chemotherapy, modified focal irradiation, or combinations of these have been used to delay or avoid the use of conventional craniospinal irradiation in order to minimize the risk for deleterious neurocognitive impairment in survivors. However, it is difficult to evaluate the impact of such approaches on intellectual and functional outcome, and results to date are limited. This review covers the most recent therapeutic advances for the most common histological subtypes of malignant infant brain tumors: medulloblastoma, supratentorial primitive neuroectodermal tumor, ependymoma, atypical teratoid rhabdoid tumor, choroid plexus carcinoma, and high-grade glioma. Survival and neurocognitive outcome are emphasized.

Feasibility of metronomic maintenance chemotherapy following high-dose chemotherapy for malignant central nervous system tumors

BACKGROUND

Children less than 5 years of age with malignant central nervous system (CNS) tumors, continue to have a high rate of morbidity and mortality following administration of conventional therapy. In an attempt to avoid the neurologic sequelae associated with craniospinal radiation, strategies such as high-dose chemotherapy (HDCT) followed by peripheral stem cell rescue have been used successfully. Metronomic chemotherapy has also been reported as a potential new treatment strategy in solid tumors, particularly in adults.

PROCEDURE

A retrospective chart analysis was performed on 10 patients less than 5 years of age with CNS tumors treated with metronomic chemotherapy shortly after HDCT as part of their clinical care.

RESULTS

Metronomic chemotherapy was associated with minimal toxicity and all patients maintained a good quality of life. At the time of this report, all 10 patients are alive. Two patients have relapsed, and the remaining eight, including six patients with metastatic disease, continue to have stable clinical and radiographic disease at a mean of 20 months from the time of diagnosis.

CONCLUSIONS

Metronomic chemotherapy in this patient population is feasible and shows encouraging preliminary results, especially in patients with metastatic disease who have not received craniospinal radiation. Further investigation of this strategy in newly diagnosed patients with CNS tumors is warranted.

Recent development in chemotherapy of paediatric brain tumours

PURPOSE OF REVIEW

Chemotherapy has gained a larger importance in the management of brain tumours, especially in children.

RECENT FINDINGS

Converging results were presented in 2005 by the German, French and North-American cooperative groups indicating that a subgroup of young children with medulloblastoma (i.e. those with desmoplastic histology) could be cured with chemotherapy only strategies. The usefulness of high-dose chemotherapy followed by stem-cell transplant was shown not only as salvage strategy but also upfront in high-risk patients with medulloblastoma. Diffuse pontine glioma remains a devastating disease despite numerous attempts to improve on the standard radiotherapy. Targeted therapies have entered the paediatric neuro-oncology field as well.

SUMMARY

In the most frequent paediatric brain tumors (medulloblastoma and low grade gliomas), the improvements have been impressive in recent years. These patients still await new targeted therapies to lower the burden of treatments and their related side-effects. Most of the brain tumours, however, are rare and the development of specific protocols too slow. Likely, they may have very specific biologic abnormalities that could be efficiently targeted in the near future.

High-grade astrocytoma in very young children

BACKGROUND

High-grade astrocytomas are rare in young children, but have been reported to have a better prognosis than similar tumors in older patients.

PROCEDURE

We retrospectively reviewed the clinical characteristics, survival, and long-term sequelae for patients younger than 3 years old with high-grade astrocytoma, treated at a single institution between 1984 and 2005.

RESULTS

Sixteen patients were included. Histology included anaplastic astrocytoma (n = 9), glioblastoma multiforme (n = 5), and malignant glioma (n = 2). All patients underwent biopsy or resection, followed by chemotherapy. Six patients received scheduled irradiation and six were irradiated at the time of disease progression. Ten patients are alive at a median follow-up of 11.6 years (range, 1.7-21.6 years). 5-year overall survival (OS) was 66.3% (SE 12.2%), and 5-year event-free survival (EFS) was 28.6% (SE 12.1%). Age at diagnosis was a significant predictor of the hazard of death in a Cox model (HR 2.871, 95%CI 1.015-8.123). Gender and histology did not predict OS or EFS. Trends toward improved OS were detected for patients with hemispheric tumors and those undergoing complete resection. All evaluable survivors (n = 9) had some neurocognitive impairment, with estimated overall cognitive ability ranging from significantly delayed to average; all survivors attending school (n = 5) performed below grade level on achievement testing. Seven of nine evaluable survivors had endocrine dysfunction.

CONCLUSIONS

Young children with high-grade astrocytoma have better long-term overall survival than older patients, but recurrence is common, and most children require irradiation. Long-term complications are frequent and often severe.

Pediatric CNS tumors: current treatment and future directions

Pediatric CNS tumors are the most common solid tumor of childhood and are the leading cause of cancer-related death in this age group. Improving prognosis is not the only challenge facing physicians managing these young patients as it is vital to consider the quality of survival. Current management strategies rely on surgery, radiotherapy and conventional cytotoxic chemotherapy, and although ongoing clinical trials continue to refine these treatments, newer approaches are required. This article will discuss current treatment standards for the most common pediatric CNS tumors: astrocytomas (low- and high-grade glioma), ependymoma and primitive neuroectodermal tumors (medulloblastoma), as well as future biological-based novel therapies.