Survival outcomes in atypical teratoid rhabdoid tumor for patients undergoing radiotherapy in a Surveillance, Epidemiology, and End Results analysis

BACKGROUND: Atypical teratoid rhabdoid tumor (ATRT) is a rare central nervous system malignancy with a poor prognosis that affects mostly young children. Although radiotherapy (RT) historically has been delayed in patients aged <3 years, emerging evidence suggests a role for RT to achieve long-term survivorship. Clinical features and age-dependent trends of RT use were evaluated for patients with ATRT. METHODS: The National Cancer Institute's Surveillance, Epidemiology, and End Results database was used to identify 144 patients with ATRT from 1973 to 2008. The primary endpoint was median overall survival (OS). Clinical and treatment variables were assessed for an association with OS using Cox proportional hazards models. Landmark analysis was used to correct for immortal time bias of adjuvant RT. RESULTS: The median age at diagnosis was 1 year (range, 0-67 years). Gross total resection of the primary tumor was achieved in 39% of patients, and 33% of patients received RT. From 1992 to 2008, RT use increased 2.4-fold in patients aged ≤3 years. The median OS for was 10 months. In multivariate analyses, metastatic disease (hazard ratio, 2.83; 95% confidence interval, 1.53-5.23; P = .001) and RT (hazard ratio, 0.10; 95% confidence interval, 0.01-0.73; P = .02) were identified as independent predictors of survival. Landmark analysis confirmed a robust association between RT use and survival, which was attenuated in patients ages 4 to 17 years compared with younger patients. CONCLUSIONS: The current results indicated that RT may offer a significant survival benefit for patients with ATRT and that patients aged ≤3 years may derive more benefit from initial RT compared with older children. The authors concluded that prospective clinical trials are needed to examine the role of RT in the initial management of ATRT in patients aged <3 years.