Genomic Biomarkers for Precision Oncology of Salivary Gland Cancer

2022 Fiscal Year Final Research Report

• Project/Area Number: 18K09340
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 56050:Otorhinolaryngology-related
• Research Institution: Okayama University (2020-2022); The University of Tokyo (2018-2019)
• Principal Investigator: Ando Mizuo 岡山大学, 医歯薬学域, 教授 (60511467)
• Project Period (FY): 2018-04-01 – 2023-03-31
• Keywords: Salivary gland cancer / Genomic alterations / Precision oncology

Outline of Final Research Achievements

We focused on salivary duct carcinoma (SDC) with pleomorphic adenoma as a precancerous lesion and performed genomic analysis of normal tissue, pleomorphic adenoma, and SDC components in the same case to determine at what stage of malignant transformation the driver mutations occur. The results suggest that inactivation of tumor suppressor genes occurs in the pleomorphic adenoma stage, while copy number aberrations caused by genomic instability are markedly increased, suggesting that these are the drivers of carcinogenesis. These findings contrast with the presence of active mutations in the HRAS and PIK3CA genes in SDCs that are not derived from pleomorphic adenomas, leading to the selection of therapeutic targets.

Free Research Field

Head and Neck Oncology

Academic Significance and Societal Importance of the Research Achievements

唾液腺導管癌は、浸潤性乳管癌に類似した病理組織像を呈する唾液腺悪性腫瘍である。唾液腺導管癌はその由来から、新規癌および多形腺腫由来癌の2種に大別される。唾液腺癌の中で最も悪性度の高い組織型であり、5年生存率は20-30%と報告されている。本研究により得られた知見は、とくに多形腺腫由来癌における重要分子を同定し、患者の治療選択の基準となる治療効果予測因子となることが期待される。