Postneoadjuvant Therapy Stage IV Gastric Cancer AJCC v8

This study will investigate the tumor-associated vasculature of patients with solid tumors. The investigators will use a technology known as intravital microscopy (IVM) in order to visualize in real-time the vessels associated with solid tumors. The IVM observations may determine if an individual patient's tumor vessels would be amenable to receiving systemic therapy, based on the functionality of the vessels.

This early phase I trial studies the effect of pembrolizumab and lenvatinib in treating patients with gastroesophageal adenocarcinoma that has spread to other places in the body (advanced/metastatic) or cannot be removed by surgery (unresectable). Immunotherapy with monoclonal antibodies, such as pembrolizumab, may help the body's immune system attack the cancer, and may interfere with the ability of tumor cells to grow and spread. Lenvatinib may stop the growth of tumor cells by blocking some of the enzymes needed for cell growth. Giving pembrolizumab and lenvatinib may kill more tumor cells.

This phase I trial studies the side effects of pressurized intraperitoneal aerosol chemotherapy (PIPAC) in treating patients with ovarian, uterine, appendiceal, stomach (gastric), or colorectal cancer that has spread to the lining of the abdominal cavity (peritoneal carcinomatosis). Chemotherapy drugs, such as cisplatin, doxorubicin, oxaliplatin, leucovorin, fluorouracil, mitomycin, and irinotecan, work in different ways to stop the growth of tumor cells, either by killing the cells, by stopping them from dividing, or by stopping them from spreading. PIPAC is a minimally invasive procedure that involves the administration of intraperitoneal chemotherapy. The study device consists of a nebulizer (a device that turns liquids into a fine mist), which is connected to a high-pressure injector, and inserted into the abdomen (part of the body that contains the digestive organs) during a laparoscopic procedure (a surgery using small incisions to introduce air and to insert a camera and other instruments in the abdominal cavity for diagnosis and/or to perform routine surgical procedures). Pressurization of the liquid chemotherapy through the study device results in aerosolization (a fine mist or spray) of the chemotherapy intra-abdominally (into the abdomen). Giving chemotherapy through PIPAC may reduce the amount of chemotherapy needed to achieve acceptable drug concentration, and therefore potentially reduces side effects and toxicities.

This phase II trial studies how well radiation therapy works for the treatment of gastrointestinal cancer that are spreading to other places in the body (metastatic). Radiation therapy uses high energy x-rays to kill cancer cells and shrink tumors. This trial is being done to determine if giving radiation therapy to patients who are being treated with immunotherapy and whose cancers are progressing (getting worse) can slow or stop the growth of their cancers. It may also help researchers determine if giving radiation therapy to one tumor can stimulate the immune system to attack other tumors in the body that are not targeted by the radiation therapy.