Oral adverse events in cancer patients treated with immune checkpoint inhibitors.

e15106 Background: Immune-checkpoint inhibitors (ICIs) are increasingly used to treat a variety of cancers. Immune-related adverse events (irAEs) have been reported. Oral manifestations of irAEs include stomatitis, oral ulcers, and xerostomia. However, the trajectory and frequency of oral irAEs remain unclear. This study aims to evaluate the prevalence, trajectory and nature of oral irAEs and their association with primary cancer diagnosis and other irAEs. Methods: A retrospective electronic chart review using the Partners Research Patient Data was performed for all patients treated with ICIs at Partners Healthcare hospitals and the Dana-Farber Cancer Institute between 12/2011 and 9/2019. Keywords specific to oral irAE such as oral mucositis, stomatitis or mouth sore were used. We collected data on demographics, cancer features, treatments, and characteristics of oral irAEs. Results: 822 of 4683 patients who received ICIs therapy were identified by keyword filtering. Lung cancer, gastrointestinal cancer, and skin cancer (including melanoma) were the most common types of primary malignancies with a frequency of 35.5%, 12.4 % and 11.7%, respectively. Oral irAEs were identified in 106 patients with the median age of 69 (range: 29-92) years and the female to male ratio of 1:1. 57.5% (n = 61) presented with symptomatic oral mucosal lesions. 47.2% (n = 50) had xerostomia and 17.0% (n = 18) had dysgeusia. The median time from the date of ICIs initiation to the date of oral irAE onset was 105 days (range: 2-631 days) in patients presented with oral mucosal lesions, 103 days (2-860 days) in xerostomia patients, and 156 days (range: 5-836 days) in dysgeusia patients. Melanoma was the most common cancer seen in oral irAE patients (30.2%), followed by lung cancer (26.4%) and oral/oropharyngeal cancer (12.3%). 60, 42, and 12 patients received pembrolizumab, nivolumab, and ipilimumab, respectively. 86.8% of oral irAE patients received only one type of ICIs therapy. Concomitant cutaneous, intestinal, and rheumatological irAEs were commonly reported with a frequency of 19.4%, 15.3%, and 12.2%, respectively in those patients. Conclusions: Oral irAEs can present with both acute and chronic onset in patients with ICIs therapy but are not as common as oral AEs associated with conventional cytotoxic regimens. While data relative to capturing oral irAEs is still preliminary, the current provides insight into their nature and course. Prospective studies focused on assessing the impact of ICI on oral irAEs are likely to provide additional insight into the character, course and impact of these conditions.