Chemotherapy response rates in recurrent/progressive pediatric glioma; Results of a systematic review

The optimum treatment strategy for recurrent childhood glioma is unknown. This report presents a systematic analysis of the currently available clinical data on chemotherapeutic management of this disease. A study protocol was prospectively developed outlining the objectives and methods of analysis including literature search strategy, eligibility criteria for published trials to be included, key data elements to be extracted and a plan for statistical analysis. Summary statistics were analyzed for the primary outcome variables. Data on recognized prognostic factors were recorded in order to adjust the outcome measures for these factors. A total of 27 non-randomized clinical trials were included in the analysis. Studies were stratified into 6 chemotherapy classes based on the frequency of drug used across studies. Average median response (complete + partial) across all drug categories was approximately 14% (range 10.4-23.5%). Adding patients with stable disease to complete and partial responders at least doubled average median response rates. Time to tumor progression ranged from 29.4 weeks to 49.7 weeks. The most frequently used drugs were the platinum analogs which demonstrated a mean TTP of 42.0 = /-23.4 weeks. Small sample sizes and the overall poor quality of the available data precluded definitive conclusions regarding the clinical impact of the various drug classes on the natural history of this disease.