2020 Volume 113 Issue 11 Pages 727-732
Patients receiving nivolumab therapy have been reported to frequently develop colitis as an immune-related adverse event (irAE). Colitis has also been reported to occur as an adverse effect of S-1 therapy, which is the salvage chemotherapy of choice after nivolumab therapy. We report 2 cases of immune-related colitis, which were difficult to distinguish from the adverse effects of S-1 therapy.
The first case was an 86-year-old woman. Nivolumab therapy was administered for local recurrence of carcinoma of the lower gingiva. The patient showed disease progression after 6 courses of nivolumab therapy, and began to receive S-1 therapy. She developed Grade 2 colitis on the 28th day after the start of S-1 therapy. A stool culture revealed a positive result for Clostridium difficile, and the patient was diagnosed as having pseudomembranous enteritis, and appropriate antibiotic therapy was administered. However, the colitis still failed to resolve. Biopsy of the colonic mucosa showed crypt abscesses. Discontinuation of S-1 therapy did not alleviate the symptoms, whereas the initiation of prednisolone therapy on the 53rd day led to immediate improvement of the symptoms. Therefore, the symptoms were diagnosed as representing an irAE of nivolumab therapy, and not an adverse effect of S-1 therapy.
The second case was a 76-year-old man. Nivolumab therapy was administered for local recurrence of hypopharyngeal carcinoma. The patient showed disease progression after 20 courses of nivolumab therapy, and was started on S-1 therapy. The patient developed Grade 3 colitis on the 34th day, but despite discontinuation of S-1, the colitis failed to improve. Colonscopy was performed, and based on the detection of ulcerative colitis-like findings of the colonic mucosa, the patient was diagnosed as having colitis as an irAE of nivolumab. A biopsy of the colonic mucosa also showed crypt abscesses. The symptoms began to improve immediately after the start of administration of prednisolone.
Colitis is a frequently encountered adverse effect of anti-cancer agents. Since discrimination between irAEs and the adverse effects of chemotherapy is often difficult, close multidisciplinary collaboration is necessary for early diagnosis and appropriate treatment.