Relationship between metabolic heterogeneity and immune marker expressions in head and neck cancers

2019 Fiscal Year Final Research Report

• Project/Area Number: 18K16870
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 56050:Otorhinolaryngology-related
• Research Institution: Kyoto University
• Principal Investigator: Kikuchi Masahiro 京都大学, 医学研究科, 助教 (90443564)
• Project Period (FY): 2018-04-01 – 2020-03-31
• Keywords: 頭頸部癌 / FDG PET / 糖代謝 / 不均一 / PD-L1 / 免疫細胞 / バイオマーカー

Outline of Final Research Achievements

The aim of this study was to evaluate pre-operative FDG PET/CT texture features and soluble PD-L1 (sPD-L1) expression in circulation as a factor predicting PD-L1 expression in tumor-microenvironments in patients with head and neck squamous cell carcinoma who underwent definitive surgery. PD-L1 expression in surgically resected specimens were evaluated using immunohistochemistry and compared with PET texture features (SUV and textural indices) and sPD-L1 concentration in preoperative serum using enzyme-linked immunosorbent assay. Patients with high SUVmax, patients with high metabolic heterogeneity, and patients with high serum level of sPD-L1 showed high PD-L1 expression in immune cells.
Preoperative FDG PET/CT texture features and serum level of sPD-L1 were predictive markers for PD-L1 expressions of immune cells.

Free Research Field

頭頸部癌免疫

Academic Significance and Societal Importance of the Research Achievements

腫瘍微小環境における免疫細胞のPD-L1発現の役割は不明であるが、腫瘍細胞のPD-L1発現と同様、腫瘍浸潤リンパ球の活性を抑制する役割があると考えられている。FDG PET検査ならびに末梢血可溶性PD-L1測定は非侵襲的な検査であり、手術前に腫瘍内の免疫細胞のPD-L1発現を評価することが可能である。これらは頭頸部癌患者の生命予後予測ならびに抗PD-1薬・抗PD-L1薬といった免疫チェックポイント阻害剤の効果予測の新たなバイオマーカーになることが期待される。