Comprehensive analysis for the association between microbiome in the gastric mucosa and malignant potential of gastric cancer

2018 Fiscal Year Final Research Report

• Project/Area Number: 16K10504
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Digestive surgery
• Research Institution: Kumamoto University
• Principal Investigator: YOSHIDA Naoya 熊本大学, 医学部附属病院, 特任准教授 (60467983)
• Co-Investigator(Kenkyū-buntansha): 今村 裕 公益財団法人がん研究会, 有明病院 消化器外科, 副医長 (70583045) ; 井田 智 公益財団法人がん研究会, 有明病院 消化器外科, 副医長 (80583038)
• Project Period (FY): 2016-04-01 – 2019-03-31
• Keywords: Fusobacterium / F. nucleatum / microbiome / 胃癌 / 食道胃接合部癌 / 予後因子

Outline of Final Research Achievements

In this study, we developed a detecting method of F. nucleatum, targeting nusG, using real-time PCR. We examined the clinicopathological, molecular characteristics, and prognostic effect of the tumor with F. nucleatum (+) tumors, compared to those without. In a total of 115 cases with gastroesophageal adenocarcinoma, F. nucleatum was detected in 40 cases (34.8%). We analyzed factors like gender, age, tumor location, H pylori infection status by gastroscopy, disease stage, PD-L1 expression on tumor cells, intra-/peri-tumoral CD8(+) lymphocyte infiltration, intra-/peri-tumoral FOP3(+) lymphocyte infiltration, EBV infection, MSI status, Ki-67 intensity, TP53 mutation, HER2 status, LINE-1 methylation level, and CpG methylator phenotype (by using MGMT, CHFR, and CDKN2A). However, there was no significant differences. We could not find any prognostic difference between the two, in disease-specific survival, time to recurrence, relapse-free survival, or overall-survival.

Free Research Field

消化器外科学、食道癌・食道胃接合部癌・胃癌、microbiome

Academic Significance and Societal Importance of the Research Achievements

microbiome は癌、肥満、炎症性腸疾患、非アルコール性脂肪性肝疾患との関連が明らかにされ、注目を集めている研究の一つである。これまで我々は大腸癌患者では腸内細菌叢の中でFusobacterium が健常人よりも多く生息し、Fusobacterium が多い症例では予後が不良であることを解明した。今回、胃腺癌や食道胃接合部腺癌におけるFusobacteriumの有無が、臨床病理的・分子生物学的に、あるいは予後・再発に影響を与えるかについて検討したが、有意な差が得られなかった。上部消化管癌においてFusobacteriumは腫瘍の悪性化に関与していない可能性が高いと考えられた。