Atypical Teratoid Rhabdoid Tumor

Atypical teratoid rhabdoid tumor (AT/RT) is a rare tumor usually diagnosed in childhood. Although usually a brain tumor, AT/RT can occur anywhere in the central nervous system (CNS) including the spinal cord. About 60% will be in the posterior cranial fossa (particularly the cerebellum). One review estimated 52% posterior fossa, 39% sPNET (supratentorial primitive neuroectodermal tumors), 5% pineal, 2% spinal, and 2% multi-focal.

In the United States, three children per 1,000,000 or around 30 new AT/RT cases are diagnosed each year. AT/RT represents around 3% of pediatric cancers of the CNS. Around 17% of all pediatric cancers involve the CNS; it is the most common childhood solid tumor. The survival rate for CNS tumors is around 60%; with AT/RT it is around 10%. Pediatric brain cancer is the second leading cause of childhood death, just after leukemia. Recent trends suggest that the rate of overall CNS tumor diagnosis is increasing by about 2.7% per year. As diagnostic techniques using genetic markers improve and are used more often, the proportion of AT/RT diagnoses is expected to increase.

Because it is highly malignant, AT/RT has a high mortality rate. A survey of 36 AT/RT patients at St. Jude Children's Research Hospital from 1984 to 2003 showed that the two-year event-free survival for children under three was 11%, the overall survival rate was 17%. For children aged 3 years or older the event-free survival was 78% and the overall survival 89%. Because most patients with AT/RT are less than three years old (71% in St Jude Study), the overall prognosis for AT/RT is very poor.

Current research is focusing on using chemotherapy protocols that are effective against rhabdomyosarcoma in combination with surgery and radiation therapy.