Pembrolizumab Before Surgery for the Treatment of Mismatch Repair Deficient Locally Advanced Solid Cancers

This phase II trial studies how well pembrolizumab works before surgery in treating patients with mismatch repair deficient solid cancers that have spread to nearby tissue or lymph nodes (locally advanced). Cancer is caused by changes (mutations) to genes (DNA) that control the way cells function, and some of these mutations can cause tumor cells to grow quickly and out of control. Microsatellite instability-high (MSI-H) tumors are made up of cancer cells that have a greater than normal number of genetic markers called microsatellites. These cancers may have defects in the ability to correct mutations that occur when DNA is copied in the cell. Similarly, mismatch repair deficient tumors (dMMR) may have difficulty repairing some type of genetic mutation during cellular replication that may affect tumor's response to cancer therapy. 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.