A gene signature for a long-term survivor of an atypical teratoid/rhabdoid tumor.

Atypical teratoid/rhabdoid tumors (AT/RTs) are aggressive brain tumors that are commonly associated with a dismal prognosis. However, there have been isolated reports of long-term survival that was not necessarily correlated with other prognostic factors such as age, clinical stage, or extent of surgical resection. Here, we report the case of a 6-year-old boy with AT/RT who remained disease-free for 8 years after undergoing subtotal surgical resection followed only by radiation therapy. On recurrence, the tumor rapidly progressed, leading to the patient's death a short time later. To further characterize this case and learn more about the tumor biology of long-term survivors, we compared the gene expression (GE) profiles from representative samples obtained from primary, recurrent, and progressive disease tumors of the above-mentioned patient along with a cohort of primary untreated AT/RT samples using cDNA microarrays. Global GE analysis and unsupervised hierarchical clustering showed the three events clustered together and distinctly apart from the rest of the samples. This indicates a GE background that is maintained throughout the course of the disease. This unique case suggests that there may be specific clinical characteristics associated with distinctive molecular subtypes of AT/RT. The identification and characterization of AT/RT subtypes could lead to advances in both prognosis and treatment of these tumors.