This research study is a Phase II clinical trial. Phase II clinical trials test the safety and effectiveness of an investigational agent to learn whether it works in treating a specific disease. Investigational means that the drug is being studied.~Pembrolizumab (MK-3475 or KEYTRUDA) is a humanized monoclonal antibody. An antibody is a common type of protein made in the body in response to a foreign substance (particles not typically found in your body such as bacteria or viruses). Antibodies attack foreign substances and protect against infection. Antibodies can also be produced in the laboratory for use in treating patients. Pembrolizumab is designed to restore the natural ability of the immune system to recognize and target cancer cells.~The FDA recently granted approval to pembrolizumab as a treatment for patients with recurrent or metastatic head and neck squamous cell carcinoma. Pembrolizumab has not been approved for treatment against adenoid cystic carcinoma.~This study is testing whether pembrolizumab with or without radiation is useful for patients with adenoid cystic carcinoma. Radiation therapy may be used to treat some ACC tumors that have spread to other parts of the body or recurred after surgery. Radiation therapy may affect the immune system to improve the efficacy of pembrolizumab
This research study is studying immunotherapy with or without radiation therapy as a possible treatment for adenoid cystic carcinoma.~The immunotherapy involved in this study is:~Pembrolizumab (MK-3475 or KEYTRUDA).