10098-MPC-10 HOW SHOULD WE RESPOND TO REPEATED WHO REVISIONS? IN-HOUSE MOLECULAR DIAGNOSIS SYSTEM BY ADVANCED MEDICAL SYSTEM

Abstract

Abstract BACKGROUND Since the WHO2016 revision, required molecular markers has been increasing, placing a burden on clinical practice of diffuse gliomas. We established an in-house molecular diagnostic platform by Senshin-Iryo (meaning advanced medical care system) and have since been partially modifying the analysis method in accordance with the WHO2021 revision. We review our achievements in total 5 years. METHODS Analyses of IDH, BRAF, and H3 point mutations, loss of heterozygosity on 1p19q and chromosomes 10 and 17, and MGMT methylation were combined into a set and submitted as a Senshin-Iryo "Drug resistance gene testing for anticancer chemotherapy" and approved in August 2018. Subsequently, in October 2021, Sanger sequencing for TERT promotor mutation was added to the set and the LOH analysis was replaced to MLPA, in order to analyze 1p19q codeletion and newly required genetic markers; EGFR, PTEN, CDKN2A, etc. in WHO2021. RESULTS The cumulative number of cases has reached over 200. Among them, 54 cases were analyzed after WHO2021 revision. The laboratory has maintained the diagnostic platform in which molecular diagnoses are steadily confirmed generally within two weeks. The initial expenditure was exceeded the income obtained from the patient co-payment, however, it has gradually been reduced to running costs alone, then is approaching profitability. After WHO2021 revision, diagnoses could be confirmed by molecular markers obtained from Senshin-Iryo in 38 of 54 cases (70.1%). Among the remaining 16, only 4 (7.4%) cases remained diagnosed as diffuse glioma, NEC, exclusionary after 12 cases in which glioblastoma was confirmed by histopathological diagnosis. CONCLUSIONS Our Senshin-Iryo trial has functioned as a salvage system to overcome the current transition period in which the continuing revision of WHO classification causing a clinical dilemma of healthcare system.