Treatment-Response Evidence, Care-Pathway Gaps, and Guideline Discordance in Gastric MALT Lymphoma: An Umbrella Review

Background/Aims: Reviews of gastric mucosa-associated lymphoid tissue lymphoma have quantified treatment response, but their coverage of the care pathway and relationship to guideline differences remain unclear. Methods: PubMed, Embase, and the Cochrane Library were searched through March 31, 2026. Eligible reviews were mapped to 13 clinical questions as direct, partial, or absent coverage. Question-specific anchors were selected without pooling overlapping reviews. All 16 items of A MeaSurement Tool to Assess systematic Reviews, version 2 were examined; overall confidence was assigned to intervention reviews. European Gastro-Intestinal Lymphoma Study, European Society for Medical Oncology, National Comprehensive Cancer Network, and British Society for Haematology recommendations were compared descriptively. Results: -negative management, endoscopic ultrasonography, bone marrow biopsy, and PET/computed tomography. No eligible review compared the relevant treatment sequences or staging strategies. Conclusions: Review-level evidence is concentrated on treatment response. It cannot establish superiority between treatment sequences or determine staging, escalation timing, surveillance, or relapse strategies. Guideline differences concern decisions for which the relevant comparisons remain unsynthesized.