Atypical teratoid rhabdoid tumors: a population-based clinical outcomes study involving 174 patients from the Surveillance, Epidemiology, and End Results database (1973-2010)

Introduction: Atypical teratoid rhabdoid tumors (ATRTs) are rare, highly malignant embryonal tumors of the central nervous system (CNS) accounting for 20% of CNS tumors in children under the age of 3. This study examines a large cohort of ATRT patients to determine demographic, clinical, and pathologic factors which impact prognosis and survival. Methods: Demographic and clinical data were abstracted on 174 ATRT patients (171 pediatric patients age <20 and 3 adult patients age >= 20) from the Surveillance, Epidemiology, and End Results database (1973-2010). Standard statistical methodology was used. Results: A total of 174 ATRT cases (mean age of 2.84 years) were identified. ATRT had a higher incidence in males (56.3%), Caucasians (59.1%), and children <3 years of age (80.5%), P< 0.001. The most common primary sites were the cerebellum (17.8%), ventricles (16.1%), and frontal lobe (12.6%). Mean overall survival was 3.2 +/- 0.4 years, while overall and - cancer-specific mortality were 63.2% and 56.3%, respectively, P= 0.005. Most ATRT cases were treated with surgery alone (58.0%), followed by a combination of surgery and radiation (34.3%), no treatment (6.5%), and radiation alone (1.2%). The use of combination therapy has increased significantly (16.1%) since 2005 (P< 0.001), while primary surgical resection and radiation therapy rates remain relatively unchanged. The longest survival was observed among ATRT patients receiving combination therapy (5.9 +/- 0.7 years), followed by radiation alone (2.8 +/- 1.2 years), and surgery alone (1.9 +/- 0.4 years), P< 0.001. Multivariable analysis identified only distant metastases (OR = 4.6) as independently associated with increased mortality, whereas combination therapy (OR = 0.4) was associated with reduced mortality, P< 0.005. Conclusion: ATRT is a rare and highly aggressive embryonal malignancy of the CNS that presents more often as locoregional tumors >4 cm in male Caucasian children of age <3 years, involving the cerebellum, ventricles, or frontal lobe. Combination therapy significantly improves survival, and its use has been increasing since 2005.