Immune checkpoint inhibitors are effective in the treatment of Epstein-Barr virus-associated gastric cancer: A case report

Gastric cancer (GC) is one of the most common malignancies globally, and its occurrence and development are associated with genetic, dietary, biological, and immune factors. Epstein-Barr virus-associated gastric cancer (EBVaGC), as a special subtype of GC, has become a research hotspot in recent years. In patients with advanced GC, Epstein-Barr virus infection is closely related to lymph node metastasis, depth of tumor invasion, and poor prognosis. There is great clinical need for a new treatment modality for EBVaGC. Advances in molecular biology and cancer genetics have led to the development of immune checkpoint inhibitors (ICIs); patients treated with ICIs experience clinical benefit and few adverse effects. PATIENT CONCERNS AND DIAGNOSES: We report a 31-year-old male with advanced EBVaGC and multiple sites of lymph node metastasis who was intolerant to multiple lines of chemotherapy. INTERVENTIONS AND OUTCOME: After immune checkpoint inhibitor treatment, both primary and metastatic tumors shrank significantly without noticeable adverse reactions. After 21 months of progression-free status, the patient underwent R0 resection. LESSONS: This case report provides evidence for the use of ICIs in treating EBVaGC. It also shows that detection of Epstein-Barr virus-encoded small nuclear RNA may be a prognostic factor in gastric cancer.