A challenge to improve preoperative diagnosis of lymph node metastasis in early gastric cancers using the liquid biopsy.

2022 Fiscal Year Final Research Report

• Project/Area Number: 21K15510
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 50010:Tumor biology-related
• Research Institution: Kagoshima University
• Principal Investigator: Daisuke Matsushita 鹿児島大学, 医歯学域鹿児島大学病院, 助教 (10724205)
• Project Period (FY): 2021-04-01 – 2023-03-31
• Keywords: Liquid biopsy / gastric cancer / less invasive surgery / lymph node metastasis

Outline of Final Research Achievements

Improving preoperative diagnosis of lymph node metastasis in early gastric cancers is an important issue to develop less invasive tailor-made surgery. We tried to obtain new biomarkers to predict pre-operative lymph node metastasis using liquid biopsy. At the preparatory experiments, we used sentinel lymph nodes of gastric cancer which reserved in our institute. Sentinel lymph node is the lymph node which received lymphatic flow directory from cancer site, and we hypothesized that predictive candidates of lymph node metastasis will be extracted from PCR-array comparing between SN and non-SN. The PCR-array, unfortunately, didn’t work to evaluate candidate because of the degradation over time of samples. Therefore, we introduced “CTC-chip”which be able to capture cancer cells from peripheral blood, directory. Now, we have started the calibration of this device and already obtain cancer cell lines spiking into normal peripheral blood as a circulating cancer cell.

Free Research Field

Digestive cancer

Academic Significance and Societal Importance of the Research Achievements

早期胃癌の治療は予防的リンパ節郭清を伴う定型的胃切除が推奨されるが、内視鏡治療の適応を外れた早期胃癌であれば実際のリンパ節転移頻度は1割もなく、9割の症例に過度の手術侵襲を加えている結果と言える。しかし、画像検査による術前リンパ節転移診断は非常に難しく、そのためにリンパ節転移を予測しうるバイオマーカーの開発が必要であり、検査自体も低侵襲な採血から行えるリキッドバイオプシーによる評価が可能となれば、多くの症例にリンパ節郭清を個別化できる低侵襲手術が行えるようになる。さらに手術の低侵襲化は術後合併症の軽減にも寄与する可能性があり、手術における入院期間の短縮による医療経済への貢献も期待される。