Clinical StudiesA Case of Response to Immunotherapy in a Patient With MSI Metastatic Colorectal Cancer and Autoimmune Disease Receiving Steroid TherapyMassucci, Maria*; Di Fabio, Francesca†; Rojas Llimpe, Fabiola L.†; Ardizzoni, Andrea*Author Information *Department of Experimental Diagnostic and Specialized Medicine, S.Orsola-Malpighi Hospital, University of Bologna †Medical Oncology Unit, S.Orsola-Malpighi Hospital, Bologna, Italy Reprints: Maria Massucci, Department of Experimental Diagnostic and Specialized Medicine, S.Orsola-Malpighi Hospital, University of Bologna, via G. Massarenti 9, Bologna 40138, Italy (e-mail: firstname.lastname@example.org). Received October 14, 2019 Accepted November 5, 2019 Online date: January 3, 2020 Journal of Immunotherapy: June 2020 - Volume 43 - Issue 5 - p 153-155 doi: 10.1097/CJI.0000000000000308 Buy Metrics Abstract Colorectal cancer is one of the most commonly diagnosed tumors worldwide and a leading cause of cancer-related death. Although the majority of gastrointestinal cancers are generally considered poorly immunogenic, recent data from clinical trials have demonstrated that the subgroup of patients with DNA mismatch repair system is highly responsive to immune checkpoint inhibitor–based therapy. We present the case of a 74-year-old man with pulmonary autoimmune intersitiopathy and microsatellite instability metastatic colorectal cancer who responded to nivolumab despite the concomitant steroid therapy. Furthermore, his autoimmune disease did not worsen during immunotherapy. Copyright © 2020 Wolters Kluwer Health, Inc. All rights reserved.