Anti-PD‑1-induced type 1 diabetes mellitus in patient with recurrent oropharyngeal squamous cell cancer

Immune checkpoint inhibitors targeting a programmed cell death ligand (PD-L1) have been a major breakthrough in the treatment of many cancers . Nivolumab is an antibody that selectively blocks the PD‑1 receptor on the surface of cytotoxic T- cells to prevent downregulation of the immune response . Immune checkpoint inhibitors can cause immune-related adverse events , including endocrine ones . Type 1 diabetes mellitus is one of the severe rare and potentially lethal immune-related adverse events diagnosed in less than 1% of patients receiving immune checkpoint inhibitors . The total incidence of type 1 diabetes mellitus associated with the PD‑1 inhibitor is relatively low ; however , it develops rapidly and is potentially life-threatening without timely diagnosis and treatment . Since PD‑1 inhibitors are widely used in cancer treatment , complications such as type 1 diabetes mellitus should attract medical attention . During treatment , specialists should help patients better recognize the symptoms of hyperglycemia or diabetic ketoacidosis , which requires careful observation , regular monitoring of blood glucose levels , rapid detection and correct diagnosis and treatment of diabetes mellitus .