Scirrhous gastric cancer is a malignant tumor in which cancer cells infiltrate widely under the mucosa and often cause peritoneal dissemination or ascites at the time of diagnosis.It is considered to be the cancer type with the worst prognosis along with pancreatic cancer.Genome analysis of whole gastric cancer or diffuse gastric cancer has been reported so far, but scirrhous gastric cancer is not often operated on, and even if a sample is available, fibrosis is strong and the content of cancer cells is low. The genomic abnormality and carcinogenic mechanism of gastric cancer were unknown.

　Therefore, the research group conducted whole-genome analysis of ascites cells by peritoneal dissemination, which are often known to exist from the early stage of the disease, for scirrhous gastric cancer, and attempted to elucidate the pathophysiology and identify therapeutic targets.

　As a result, we identified a number of genetic abnormalities characteristic of scirrhous gastric cancer, and found that about a quarter of the total could be expected to be effective with existing molecular-targeted drugs.Furthermore, when a peritoneal dissemination model mouse was prepared using a cell line established from cancer cells in ascites and each inhibitor was administered, suppression of cancer cell growth or disappearance of peritoneal dissemination was confirmed.

　Since early detection of scirrhous gastric cancer is difficult and treatment is difficult due to peritoneal dissemination in which cancer cells are scattered in the stomach, treatment for suppressing carcinogenesis and peritoneal dissemination is required.In the future, the company plans to continue studying clinical development for cancer patients, aiming to implement it in oncogene panel tests (simultaneous tests of many genes) and to develop molecular-targeted therapeutic agents.

Paper information:[Nature Cancer] Multi-omic profiling of peritoneal metastases in gastric cancer identifies molecular subtypes and therapeutic vulnerabilities