Preoperative Pembrolizumab and Chemotherapy in Resectable, Recurrent HNSCC

This research study is evaluating effectiveness and safety of a combination of immunotherapy drug, pembrolizumab, with chemotherapy, as a possible treatment before and after surgery for squamous cell carcinoma of the head and neck (HNSCC). The combination of pembrolizumab and chemotherapy will be given prior to your surgery, while immunotherapy pembrolizumab will be continued for approximately 1 year after surgery. The names of the study drugs involved in this research study are: * pembrolizumab (a type of immunotherapy) * docetaxel (a type of chemotherapy) * cisplatin (a type of chemotherapy) * carboplatin (a type of chemotherapy)