PTC-Guided Therapy for Peritoneal Mesothelioma

Official Title: A Study of Key Parameters and Mechanisms in Personalized Diagnosis and Treatment Using Tumor Models Why is this study being done? This research study is for adults with a type of cancer called Malignant Peritoneal Mesothelioma (MPM). Currently, it is hard for doctors to know which treatment will work best for each patient after surgery. This study will test a new, personalized way to choose treatments using a model grown from a patient's own tumor in the lab, called a Patient-derived tumor-like cell cluster (PTC) model. The main goal is to see if using this PTC model to guide treatment can help patients live longer without their cancer getting worse, compared to a standard chemotherapy treatment. Who can participate? Adults aged 18 and older with a specific type of MPM (epithelioid or biphasic) who are planned to have surgery and heated chemotherapy (CRS+HIPEC) and can provide a tumor sample for the PTC model may be eligible. What will happen in the study? * Participants will be randomly assigned to one of two groups by chance, like flipping a coin. * Standard Treatment Group: This group will receive the standard chemotherapy combination of Gemcitabine, Oxaliplatin, and Apatinib. Additionally, if the patient's tumor tests positive for PD-L1 (≥1%), the immunotherapy drug Sintilimab will be given together with the chemotherapy. * Personalized Treatment Group: This group will have a PTC model made from their tumor. The model will be tested with different drugs (chemotherapy, targeted therapy, and immunotherapy) in the lab. The treatment that works best on the model will be chosen for the patient. * Both groups will receive their assigned treatment for 6 cycles. * Participants will be followed for several years to see how they are doing, through clinic visits and scans. What are the possible benefits? Participants in the personalized treatment group might receive a therapy that is more effective for their specific cancer. The information from this s