Resectable Skin Squamous Cell Carcinoma

This phase I trial tests the safety and side effects radiotherapy in combination with atezolizumab in treating patients with cutaneous squamous cell cancer that has spread to nearby tissue or lymph nodes (locally advanced) and can be removed from surgery (resectable) or cannot be remove by surgery (unresectable). Stereotactic body radiation therapy uses special equipment to position a patient and deliver radiation to tumors with high precision. This method may kill tumor cells with fewer doses over a shorter period and cause less damage to normal tissue. Immunotherapy with monoclonal antibodies, such as atezolizumab, may help the body's immune system attack the cancer, and may interfere with the ability of tumor cells to grow and spread. Giving radiotherapy in combination with atezolizumab may help improve outcomes for remission (cancer that is under control) than taking either treatment separately.