A Therapy-Terminating Event: Programmed Death-1 Inhibitor-Induced Mucositis

Oral mucositis is a painful inflammatory response that can lead to infection, cachexia, and therapy termination. This immune-related adverse event (IRAE) has been well documented within the newly developing field of immunotherapy. This case series presents three patients, aged 73 to 81 years, who were undergoing treatment with programmed death-1 (PD-1) immunotherapy for cancer; each patient developed grade III mucositis, one after the fourth cycle and two after the seventh. All three patients had no prior history of oral pathology, yet each patient reported ulcerated and inflamed oral mucosa that was swollen and painful. These lesions involved various locations within the oral cavity and caused irritation to the point of dysphagia and odynophagia. Conservative treatments such as oral anesthetic and mouthwashes with antimicrobial properties had minimal effects. Each patient thereafter was started on systemic glucocorticoids in addition to the local treatments. The initiation of a systemic treatment resulted in a resolution of the oral lesions allowing each patient the option to return to their prior immunotherapy. Mucositis is uncommon and has no standardized treatment. This case series emphasizes the debilitative result of immunotherapy-induced mucositis and illustrates the need for systemic glucocorticoids. While conservative treatments such as oral mouthwashes can be effective in treating the symptoms of mucositis, the initiation of high-dose steroids with a prolonged taper has been shown to treat the condition at its source. Early recognition of mucositis with prompt initiation of steroids has proven to be the effective mainstay treatment to relieve mucositis while limiting pauses in cancer treatment.