Immunotherapy-Related Gastritis in Small Cell Lung Cancer Treatment With Durvalumab-A Case Report

Durvalumab is a PD-L1 inhibitor that triggers a blockade resulting in enhanced anti-tumor responses related to increased T-cell activation. There is potential for numerous immune-related adverse events (irAEs) with this treatment, most of which have been shown to be effectively managed with high-dose steroids. Immunotherapy-related gastritis, while rare compared to other irAEs is an emerging concern as the use of immune checkpoint inhibitors (ICIs) increases.

This case study examines a 66-year-old female with extensive-stage small cell lung cancer (ES-SCLC) treated with durvalumab, alongside chemotherapy. Twenty-three months into treatment, she developed non-specific gastrointestinal (GI) symptoms including abdominal pain, appetite loss, and significant weight loss. Despite conservative management, resolution only occurred following the use of high-dose steroids, a finding consistent with immunotherapy-related gastritis. The patient then went onto a successful rechallenge of immunotherapy.

This case represents the first report on the rare occurrence of immune-related gastritis in an ES-SCLC patient who has been on immunotherapy for nearly 2 years. Current literature is limited in the understanding of underlying mechanisms of PD-L1-related irAEs and optimal management strategies for rare toxicities like gastritis in immunotherapy-treated cancer patients. This report aims to address the unmet need for further research on rare toxicities to immunotherapy in unique cases.