Primary radiotherapy for childhood ependymoma?

摘要

The article by Grundy and colleagues in a recent issue of The Lancet Oncology tested the hypothesis that chemotherapy would delay or eliminate the need for radiotherapy in children with CNS tumours and, therefore, decrease late toxic effects associated with radiotherapy without compromising treatment efficacy. The authors are to be commended on undertaking one of the largest phase II trials for this vexing disease. Given this hypothesis, however, one must ask whether the results support the authors' conclusions, and some of their conclusions seem to need tempering, especially with regard to the role of primary radiotherapy in the treatment of childhood ependymoma. First, the authors compare their results to the phase II trial of conformal radiotherapy done at St Jude Children's Research Hospital (Memphis, TN, USA), which involved 88 children with ependymoma (48 [55%] of whom were <3 years of age). Grundy and colleagues state that the 3-year overall survival of 79.3% in their study was higher than the 3-year progression-free survival of 69.5% in the St Jude study. Although the overall survival was not reported in the St Jude study, equating overall survival with event-free survival (EFS) seems unreasonable. The appropriate comparison would be 3-year EFS in the study by Grundy and colleagues of 47.6% (95%CI 36.2-58.1) compared with the predicted 3-year EFS in the St Jude study of 74.7+-5.7%. In the UK study, even when confined to the favourable subgroup of patients without metastases at diagnosis, only 35% (28 of 80) of patients were progression free without radiotherapy.