Abstract
Patients with cancer and pre-existing autoimmune diseases have been excluded from immunotherapy clinical trials. So, studying these patients who received immunotherapy is critical to increasing evidence of the treatment's safety and efficacy in this population. Furthermore, a complete and durable response to immunotherapy in metastatic non-small cell lung cancer (NSCLC) is rare. Therefore, it is imperative to study patients with a complete response in order to identify potential predictors of response to immunotherapy. In this case report, we highlight a 62-year-old man with a smoking history and Graves' disease who achieved a complete response with immunotherapy for metastatic NSCLC, with a long-lasting response and no immune-related adverse events. Male gender, high programmed death-ligand 1 expression, current smokers, epidermal growth factor receptor and anaplastic lymphoma kinase wild types could be biomarkers of response to immune checkpoint inhibitors presented at baseline. Caution should be exercised when interpreting this finding because it represents our patient.