Genetic alterations and expressions of immune check point molecules in salivary gland cancer

2019 Fiscal Year Final Research Report

• Project/Area Number: 17K11384
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Otorhinolaryngology
• Research Institution: Kobe University
• Principal Investigator: Kiyota Naomi 神戸大学, 医学部附属病院, 特命准教授 (40515037)
• Project Period (FY): 2017-04-01 – 2020-03-31
• Keywords: 唾液腺癌 / 遺伝子変化 / 免疫チェックポイント

Outline of Final Research Achievements

Total of 35 cases with salivary gland cancer were analyzed. The pathological types of these cases are mucoepidermoid carcinoma(MEC) low-grade, high-grade, salivary duct carcinoma(SDC), adenocarcinoma (ANOS) and adenoid cystic carcinoma (ACC) and 7 cases in each.
Genetic analyses were performed with Oncomine Tumor Mutation Load Assay and multiplex immunohistochemistry was performed with CD3/CD4/CD8/CD204/FOXP3/PD-L1/PD-L2. Tumor mutational load appeared to be higher in MEC-high, SDC and ANOS. From the multiplex immunohistochemistry analysis, intra-tumor Treg and PD-L1 positive cell were suggested to be poor prognostic factors for disease-free survival irrespective of pathological subtypes.

Free Research Field

臨床腫瘍学

Academic Significance and Societal Importance of the Research Achievements

唾液腺癌は希少がんであり手術以外に標準的治療はなく、治療選択肢が乏しい状況である。特に再発及び転移を生じた場合に確立した薬物療法もない。しかし、今回の遺伝子変異量解析と免疫チェックポイント分子発現を主たる組織型で解析した結果からは、粘表皮癌（High grade)、唾液腺導管癌、腺癌においては免疫チェックポイント阻害薬による治療介入が有効な可能性が示唆され、治療開発が進まない唾液腺癌に対して免疫チェックポイント阻害薬を用いた臨床研究を推進する根拠となる点で有意義である。