Pathologic Stage IVB Gastroesophageal Junction Adenocarcinoma AJCC v8

This phase II trial studies the effect of avapritinib in treating malignant solid tumors that have a genetic change (mutation) in CKIT or PDGFRA and have spread to nearby tissue or lymph nodes (locally advanced) or other places in the body (metastatic). Avapritinib may stop the growth of tumor cells by blocking some of the enzymes needed for cell growth. Avapritinib may help to control the growth of malignant solid tumors.

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 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.