title: Atypical teratoid rhabdoid tumors: a population-based clinical outcomes study involving 174 patients from the Surveillance, Epidemiology, and End Results database (1973-2010).
abstract: BACKGROUND
  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.
  
  
  CONCLUSIONS
  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.
authors.affiliation: Department of Surgery, Saint Barnabas Medical Center, Livingston, NJ, USA ; Saint George's University School of Medicine, Grenada, West Indies.
authors.forename: Christine Sm
authors.initials: CS
authors.lastname: Lau
authors.affiliation: Department of Surgery, Saint Barnabas Medical Center, Livingston, NJ, USA.
authors.forename: Krishnaraj
authors.initials: K
authors.lastname: Mahendraraj
authors.affiliation: Department of Surgery, Saint Barnabas Medical Center, Livingston, NJ, USA ; Saint George's University School of Medicine, Grenada, West Indies ; Department of Surgery, New Jersey Medical School, Rutgers University, Newark, NJ, USA.
authors.forename: Ronald S
authors.initials: RS
authors.lastname: Chamberlain
keywords: SEER database; central nervous system; childhood brain cancer; pediatric cancer; rare tumors