Introduction: Immune checkpoint-inhibitors (ICIs) improve the survival in certain cancers. Side effects of ICIs might limit its use, and little is known about gastric toxicity. Accordingly, we used a large database to investigate the epidemiology of ICI-induced gastritis and describe underlying associations.
Methods: A multi-institutional database (Explorys Inc, Cleveland, OH, USA), an aggregate of electronic health record data from 26 US healthcare systems was surveyed. A cohort of patients who were on ICIs (atezolizumab, ipilimumab, nivolumab and pembrolizumab) between 2011 and 2022 was identified. Subsequently, patients who developed new Systematized Nomenclature of Medicine-Clinical Terms diagnosis of gastritis after taking ICIs were selected. The prevalence of ICI-induced gastritis was calculated, and underlying associations were described.
Results: Of more than 70 million patients in the database, we identified 20,200 (0.03%) with history of ICI use (Table 1). There were 2260 (11.2%) patients who developed a new diagnosis of ICI-induced gastritis after at least 1 day of starting ICI therapy. Patients who developed ICI-induced gastritis were more likely to be female [OR: 1.18; 95% CI 1.08–1.29] and more likely to be Caucasian [OR: 1.27; 95% CI 1.12–1.44] compared to all the patients who took ICIs and didn't develop gastritis. There were no statistically significant age-based differences. Overall, patients who received any ICI had a significantly higher risk of gastritis compared to the general population [OR: 2.53; 95% CI 2.43–2.65]. Patients who received ipilimumab had the highest odds of developing ICI-induced gastritis (Figure 1).
Discussion: In this large retrospective study, we found that patients taking ICI have a higher risk of gastritis compared to the general population. In particular, Ipilimumab is associated with a disproportionally high risk of gastritis. The risk of gastritis should be discussed with all patients prior to initiating an ICI, as it may be a factor in choosing among ICIs.
