PD-1 Inhibitors in Recurrent or Metastatic Oral Squamous Cell Carcinoma: Clinical Evidence, Patient Selection, and Immune-Related Toxicities

Oral squamous cell carcinoma (OSCC) is a difficult disease to treat when local therapy is not curative, particularly if it does recur or metastasize. There is evidence of programmed cell death protein 1 (PD-1) inhibitors available to treat head and neck squamous cell carcinoma ( OSCC) but comes from mixed populations of head and neck cancer. The current narrative review outlines evidence regarding pembrolizumab and nivolumab, focusing on treatment selection and IRTs. Pembrolizumab is used either alone or in combination with chemotherapy, depending on programmed death-ligand 1 combined positive score (PD-L1 CPS), disease burden, urgency, fitness and patient preferences. In eligible post platinum setting, there is evidence for nivolumab and pembrolizumab, though treatment after PD-1 exposure will be affected. Baseline evaluation and monitoring of toxicities is required, as well as rapid management based on severity, for the skin, endocrine, gastrointestinal, hepatic, pulmonary, cardiovascular, renal, neurological, and oral systems. Specific estimates for OSCCs are still scarce. Further treatment studies in the oral cavity region, the establishment of predictive markers, the development of resistance-directed treatments and the standardization of reporting on oral cavity toxicity will help optimize treatment and patient outcomes.