CMET-15. META-ANALYSIS OF TREATMENT MODALITIES IN METASTATIC ATYPICAL TERATOID/RHABDOID TUMORS IN CHILDREN

Abstract

The aim of this study is to investigate the efficacy of different treatment modalities associated with best outcomes in the management of metastatic central nervous system (CNS) atypical teratoid/rhabdoid tumors (AT/RT) in children, which represent around 20% of newly-diagnosed AT/RT cases and are associated with dismal prognosis. A review of 1,433 peer-reviewed manuscripts from 1993 through June 2017 revealed 27 studies with a total of 80 metastatic AT/RT patients. The 3-year overall survival (OS) was 30% (95% confidence interval: 21–40%). Though treatment protocols varied widely by institution, the most-effective at improving the OS were the Medical University of Vienna AT/RT protocol, which incorporates radiation therapy (RT), intrathecal chemotherapy (IT), marrow-ablative chemotherapy and autologous hematopoietic progenitor cell rescue (AuHPCR) (3-year OS = 100%), and the Dana Farber protocol, which incorporates RT and IT (3-year OS = 57%). Gross total resection of the primary tumor was not associated with a significant improvement in the OS (p = 0.938). These results are further supported by a multivariable analysis, in which RT (p = 0.0139), IT (p = 0.0322), and AuHPCR (p <0.0001) were all independently associated with a reduced risk of death, with AuHPCR having the greatest impact on OS (Hazard Ratio = 0.21). Multimodal treatment approach should be incorporated in the management of metastatic CNS AT/RT in children and may include AuHPCR, with adjuvant RT and IT. Given the rarity of published research focused on metastatic AT/RT, these conclusions may be an important step towards the creation of standard treatment guidelines for metastatic AT/RT patients.