Circulating tumor DNA in individuals with stomach adenocarcinoma (STAD) to detect MMR-related gene alterations.

• DOI: 10.1200/jco.2023.41.16_suppl.e16083
• Publication Date: 2023-06-04T15:38:35Z
• Authors: Shi Zhang; Guoqiang Wang; Beiping Zhong; Name Fang; Aiwei Zhou; Minchao Liang; Yingqiang Li; Zhang Jing; Shaochen Cheng
• Keywords: MSH2; MLH1; PMS2; MSH6; Microsatellite Instability; Lynch Syndrome

e16083 Background: Stomach adenocarcinoma (STAD) ranks as the second incidence rate in China. The MisMatch Repair (MMR), composed of MLH1, MSH2, MSH3, MSH6, and PMS2, is a critical mechanism for repairing DNA error. In case microsatellite instability (MSI), MMR system capable mismatches. MSI-high (MSI-H) created result deficient mismatch repair (dMMR). A numerous studies have established clinical importance both MSI diagnosis, prognosis, treatment STAD. Circulating tumor (ctDNA) provides non-invasive method diagnosis prognosis cancer. examination MMR-related gene mutations STAD can serve means evaluating utility ctDNA detecting. Methods: genes list was collected from relevant literature. genetic mutation data 441 samples were obtained cBioPortal. Kaplan-Meier survival analysis used to evaluate total (OS) published set. 680 patients with TP53 screened analyzed HapLab database. Results: An TCGA indicated that 356 had wild-type 85 mutations. MSH3 accounted 19.27% overall 42.35% mutations, 36 patients. terms OS, better compared those (log-rank test, p-value = 0.028). single-gene prognostic analysis, (p-value 0.0004), while no statistical differences found other genes. monitoring using ctDNA, 12.35% (84/680) their tissue. After treatment, proportion detected 11.91% (81/680), 3.57% (3/84). Conclusions: results showed significant association between status Monogenic highly associated survival, circulating blood highlight detecting assessment through