What happened, in summary

A man with CTLA4 insufficiency had years of severe gastrointestinal problems, including recurrent hospitalizations, appendicitis and chronic diarrhea. At age 42, gastroscopy showed severe atrophic gastritis with extensive intestinal metaplasia. Two tubular adenomas contained in situ gastric adenocarcinoma, and the lesions were removed extensively by endoscopic resection.

Testing of gastric biopsies detected EBV as well as CMV and Helicobacter pylori. In the cohort analysis, his gastric cancer was grouped among the EBV-associated cases. His underlying immune disease required treatment with agents including abatacept, sirolimus and ustekinumab, but those therapies were used for CTLA4-associated intestinal disease rather than as gastric-cancer treatment.

At the first control gastroscopy 6 months after the cancer diagnosis, two tubular adenomas were described as quiescent and showed only low-grade dysplasia. Continued endoscopic follow-up was planned, with gastrectomy considered if the gastric disease worsened. He remained under close endoscopic surveillance, with gastrectomy reserved for future worsening of the gastric disease.