Accuracy analysis of high frequency mutation tumor identification testings for precise personalized medicine.

2022 Fiscal Year Final Research Report

• Project/Area Number: 20K16955
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 53010:Gastroenterology-related
• Research Institution: Hamamatsu University School of Medicine
• Principal Investigator: Yamanaka Katsumasa 浜松医科大学, 医学部附属病院, 臨床検査技師 (80838061)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Keywords: 大腸がん / マイクロサテライト不安定性 / 免疫染色 / 精度管理

Outline of Final Research Achievements

In gastrointestinal cancers, microsatellite instability (MSI) testing or immunohistochemistry (IHC) for DNA mismatch repair proteins (MMRP) is conducted to determine the use of immune checkpoint inhibitors. Since these tests have different techniques and principles, there is a possibility of result discrepancies. Our aim was to confirm the concordance rate between MSI testing and IHC testing and identify factors that affect the results to improve the accuracy of the tests. The concordance rate between the two results was 77.8%. Furthermore, inadequate sample fixation was the cause of result discrepancies. IHC testing may be more suitable for biopsy samples with better fixation compared to surgical specimens.

Free Research Field

消化器がん

Academic Significance and Societal Importance of the Research Achievements

消化器がんでは、免疫チェックポイント阻害剤を使用するために、マイクロサテライト不安定性（MSI）検査またはDNAミスマッチ修復タンパク（MMRP)の免疫染色（IHC）を用いて判定を実施している。我々はこれらの検査の特性を理解し、より精確な検査体制の構築を目指した。MSI検査とIHC検査における検査結果の一致率を確認して、結果に影響する因子を同定し、対応方法を明らかにしたことによって、高頻度変異がん判定検査における精度の向上に寄与したと考えられた。