C. S. Lau1,3, K. Mahendraraj1, R. S. Chamberlain1,2,3 1Saint Barnabas Medical Center,Department Of Surgery,Livingston, NJ, USA 2New Jersey Medical School,Department Of Surgery,Newark, NJ, USA 3Saint George’s University,Grenada, Grenada, Grenada
Introduction: Atypical teratoid rhabdoid tumors (ATRT) are rare, highly malignant embryonal malignancies of the central nervous system (CNS) accounting for ~3% of pediatric brain tumors, but ~20% of CNS tumors in children under the age of 3. To date few cases of ATRT have been reported, and no large patient series exist. This study examined a large cohort of ATRT patients to determine demographic, clinical, and pathologic factors which determine prognosis and survival.
Methods: Demographic and clinical data were abstracted on 174 patients from the SEER database from 1973–2010 and statistical analysis was performed using Chi-square test, paired t-test, multivariate analysis, and Kaplan-Meier functions.
Results: 174 cases of ATRT, with a mean age of 2.84 years were identified. 140 (80.5%) patients were <3 years old, 31 were 4-19 (17.8%) and 3 were ≥ 20 (1.7%), p<0.001. ATRT had a higher incidence in males (56.3% vs. 43.7%, p<0.001) and Caucasians (59.1%, p<0.001). The most common primary tumor sites were the cerebellum (17.8%), ventricles (16.1%), and frontal lobe (12.6%). Mean overall survival for ATRT was 3.2 ± 0.4 years, while overall and cancer specific mortality were 63.2% and 60.5% respectively (p=0.005). The majority of ATRT cases were treated with surgery alone (58.0%), followed by combination surgery and radiation (34.3%), no treatment (6.5%), and radiation alone (1.2%). The percentage of ATRT cases managed by combination surgery and radiation was significantly higher in the 2005-present study period compared to the 1973-2004 period (38.4% vs. 22.3%, p<0.001), while primary surgical resection and radiotherapy rates remained approximately the same. Longest survival was amongst ATRT patients receiving surgery and radiation (5.9 ± 0.7 years), followed by radiation alone (2.8 ± 1.2 years), surgery alone (1.9 ± 0.4 years) and no treatment (0.3 ± 0.2 years), p<0.001. Multivariate analysis identified distant metastases (OR 4.6, CI=2.7-6.9) as independently associated with increased mortality, p<0.005. Conversely, combination surgery and radiation treatment (OR 0.4, CI=0.1-2.0) was independently associated with reduced mortality, p<0.005.
Conclusions: ATRT is a rare, highly aggressive embryonal malignancy of the CNS that presents more often in male Caucasian children under the age of three, in the cerebellum, ventricles and frontal lobe with locoregional distribution and tumor sizes over 4cm. Combination surgery and radiotherapy significantly improves survival, and its use has been increasing since 2005. All ATRT patients should be enrolled into clinical trials or registries to allow for more defined multimodality management to achieve the best prognosis.
