10019- MPC-4 IN-HOUSE MOLECULAR DIAGNOSIS FOR THE ERA OF MOLECULAR STRATIFIED THERAPY OF GLIOMAS

Abstract OBJECTIVE Molecular diagnostics has become increasingly diverse since its formal adoption at WHO 2016 and then WHO 2021. In addition, with the forthcoming approval of molecular targeted therapies for IDH and BRAF, there is a need to explore molecular diagnostic systems that are compatible with clinical practice. While it is desirable to establish molecular diagnostic systems that can be completed within an institution for rapid post-diagnosis treatment, optimization of analytical methods with consideration of cost and simplicity is an important issue. We investigated the optimization of such molecular diagnostics at our institution. METHODS The author established an institutional molecular diagnostic system by combining MGMT methylation analysis by MS-PCR in addition to HRM analysis for point mutations of IDH1/2, BRAF, and H3, TERT promoter mutation analysis by Sanger sequencing, and MLPA using two different probe sets at a previous institution. After transferring to the current facility, we attempt to optimize molecular diagnostics within the facility with limited research funding. RESULTS The HRM system is low-cost, technically simple, and can detect stable results for IDH1/2, BRAF, and H3 mutations in a short time, and was easy to implement at the new facility. In addition, the newly developed MLPA probe set enabled single-step combined analysis of IDH, TERT, and MLPA methylation without bisulfite treatment. Given the usefulness of TERT as a molecular marker for glioblastoma and a surrogate marker for 1p19q, these two assays alone are now generally sufficient for the in-house molecular diagnosis of diffuse glioma in adults. CONCLUSION HRM and MLPA were suitable for the establishment of a sustainable molecular diagnostic system. Since the establishment of treatment strategies based on molecular diagnosis has become essential in recent years, and the optimization of an in-house molecular diagnosis system is desirable, so we will continue to study this issue.