PATH-49. INTRA-OPERATIVE GENETIC ANALYSES FOR DECISION-MAKING DURING TUMOR REMOVAL OF ADULT-TYPE DIFFUSE GLIOMA USING RAPID QUANTITATIVE PCR DEVICE

Abstract

Abstract BACKGROUND Recent comprehensive molecular analyses of central nervous system (CNS) tumors identified several diagnostic or prognostic markers. Especially, for adult-type diffuse glioma, IDH mutation, TERT promoter (pTERT) mutation and CDKN2A homozygous deletion are quite important markers for diagnosis and prognosis of this type of glioma. Intra-operative identification of these molecular alterations could be effective for decision-making of tumor removal strategy. METHODS In this study, we established intra-operative gene analysis method using rapid quantitative PCR device, GeneSoC, by which we could obtain genotype of these important genes for 20 minutes in an operating room. Using GeneSoC, we could perform 50 cycles of quantitative PCR for approximately 12 minutes. Results; We established rapid gene analyses of mutations of IDH1 R132H, pTERT C225T, pTERT C250T and homozygous deletion of CDKN2A for adult-type diffuse gliomas. For elution of DNA, we incubated at least 1mg of tumor tissue at 95°for 5 minutes. Combined this boiling method with GeneSoC, we could obtain those genetic alterations for 20 minutes after collection of tumor tissue. In analyses of 111 adult-type diffuse glioma cases, sensitivity and specificity for detection of IDH1 p.R132H are 98% and 98%, respectively, and those of pTERT (C225T or C250T) are 100% and 100%, respectively. In analyses of 50 cases, sensitivity and specificity for detection of CDKN2A homozygous deletion are 100% and 83%, respectively. Conclusion; In this study, we could obtain the genotype of important molecular markers intra-operatively, not only during tumor removal but even during tumor biopsy, using GeneSoC device. This rapid genetic analysis might be effective not only for intra-operative diagnosis but also for detection of boundary between tumor and normal tissue.