Peritoneal metastasis (PM) in gastric cancer is associated with a poor prognosis.~Laparoscopy with cytology is performed to evaluate for peritoneal spread when considering chemoradiation or surgery. However, the laparoscopy is invasive and the sensitivity of computed tomography (CT) scan is poor for detecting PM. Therefore, it is necessary to evaluate the feasibility of cfDNA methylation and other blood-based biomarkers for the PM diagnosis.~The study will enroll 384 participants with gastric cancer. Baseline blood and diagnosis of PM by laparoscopy with cytology will be collected. Participants with PM will be defined as the case arm and participants without PM will be defined as the control arm. A PM diagnostic model will be developed.
This study is a prospective, multi-omics, observational study aimed at detecting peritoneal metastasis of gastric cancer by combined assays for methylation of cell-free DNA (cfDNA) and other blood-based biomarkers. The study will enroll 384 participants with gastric cancer.