Clinical utility of liquid biopsy using peritoneal lavage for peritoneal dissemination of pancreatic cancer

2022 Fiscal Year Final Research Report

• Project/Area Number: 21K20823
• Research Category: Grant-in-Aid for Research Activity Start-up
• Allocation Type: Multi-year Fund
• Review Section: 0901:Oncology and related fields
• Research Institution: Tohoku University
• Principal Investigator: Chiba Kazuharu 東北大学, 医学系研究科, 大学院非常勤講師 (50769627)
• Project Period (FY): 2021-08-30 – 2023-03-31
• Keywords: 膵癌 / リキッドバイオプシー / 腹腔洗浄液 / 腫瘍由来DNA / 腹膜転移 / 腹腔内微小転移 / 個別化医療

Outline of Final Research Achievements

In this study, we aimed to diagnose and predict intra-abdominal metastasis in pancreatic cancer using analysis of peritoneal lavage. Since 2018, we have conducted a biomarker search using peritoneal lavage collected when pancreatic cancer was diagnosed and surgery was planned and searched in the abdominal cavity at Tohoku University Department of Gastroenterology.
Tumor markers in the peritoneal lavage were analyzed from a total of 149 samples, and the presence or absence of cancer-derived DNA and allele frequency were analyzed using real-time PCR and droplet-digital PCR, using KRAS gene mutation as a benchmark which is found in more than 90% of pancreatic cancer cases and the corresponding blood By comparing with corresponding blood samples, it was found that intra-abdominal metastases have significantly more tumor-derived DNA in the peritoneal lavage fluid.

Free Research Field

消化器外科学

Academic Significance and Societal Importance of the Research Achievements

膵癌の本邦における5年生存率は10％未満と予後不良な難治性癌であり、原因として診断時の転移頻度の高さや治癒切除後の高い再発率が挙げられる。切除後再発の形式として腹膜播種再発は肝転移再発の次に多く、再発後の予後は極めて不良である。腹膜播種再発は、臓器再発と比べその機序が異なり、その転移形式はまだ明らかではない。腹腔洗浄液は腹膜に直接生理食塩水を振り掛け、腹腔内から回収した液性検体であり、腹腔洗浄液中の癌由来のcfDNAの存在は腹膜播種の潜在性や危険性を示唆するバイオマーカーとして極めて有用である。それら遺伝子の網羅的解析により、腹膜播種の機序及び薬物標的遺伝子の同定に至る可能性がある。