Biomarker Analysis of HIPEC Combined With PD1/PDL1 Inhibitor for Gastric Cancer With Peritoneal Metastasis

A single-center, observational study, integrated biomarker analysis of HIPEC combined Programmed cell death 1 /Programmed cell death 1 ligand 1(PD1/PDL1)inhibitor in previously treated patients of advanced gastric cancer with peritoneal metastasis. Tests will be performed on tumor tissue and blood samples, and imaging assessments will be reviewed in order to monitor how well each patient responds to treatment. This is an observational study, so participants will not receive cancer treatment, other than the treatment received as standard of care.

Inclusion Criteria:Advanced gastric (gastroesophageal junction) adenocarcinoma confirmed by histology;Age 18-75 years, Male or Non-pregnant femaleEastern Cooperative Oncology Group(ECOG): 0~1；Negative for human epidermal growth factor receptor 2(HER-2) by immunocytochemistry or fluorescence in situ hybridization；The presence of gastric cancer peritoneal metastasis is confirmed by laparoscopic exploration, and the PCI≤20；Patients had received HIPEC combined with PD1/PDL1 inhibitor conversion therapy.Signed the Informed Consent Form, and blood and tissue samples can be obtained;Exclusion Criteria:Other distal metastases besides peritoneal metastases (e.g., liver, lung, pleural, brain, bone metastases, etc.);Other patients who were considered unsuitable for inclusion by the researchers;