GE-35 THE THERAPEUTIC CHANGES OF ATYPICAL TERATOID/RHABDOID TUMOR IN MOLECULAR CHARACTERS

BACKGROUND: Atypical teratoid/rhabdoid tumor (AT/RT) is a highly malignant tumor in early childhood. Though it is widely known that over 90% of tumors show loss of INI1 nuclear staining histologically, at this point comprehended molecular analysis of this tumor has not been done. In this report, we investigate the differences between primary tumor, recurrent tumor post induction chemotherapy, and the tumor post radiation therapy in the profiling of expression genes. MATERIALS AND METHODS: We had 3 cases of AT/RT patients who had several surgical interventions. Using these tumor tissues, we investigated the changes between primary and recurrent tumors, histological and molecular biologically with a commercially utilized SNP array system. (OncoScan, FFPE Assay Kit, Affymetrix) The data were analyzed with a commercially utilized software (Nexus Express Software). RESULTS: We have made copy number analysis and mutation study in cancer specific genes. Several common changes in molecular sense can be seen after interventions, such as specific drug treatments and radiation therapy. CONCLUSION: Our study may show how this tumor acquires the resistance to conventional therapies. Further study is needed to identify the malignant characters of this tumor.