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Copyright: ©Author(s) 2026. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution-NonCommercial (CC BY-NC 4.0) license. No commercial re-use. See permissions. Published by Baishideng Publishing Group Inc.
World J Gastrointest Oncol. Dec 15, 2026; 18(12): 126418
Published online Dec 15, 2026. doi: 10.4251/wjgo.126418
Helicobacter pylori status in gastric cancer immunotherapy: Conflicting clinical associations, immune-microbial mechanisms, and biomarker challenges
Di Zhang, Shu-Han Li, Wei-Hao Zhang, Jun Weng, Ze-Hua Li, Kun-Hao Bai
Di Zhang, School of Nursing, Sun Yat-sen University, Guangzhou 510080, Guangdong Province, China
Shu-Han Li, Institute of Transfusion, Chinese Academy of Medical Sciences, Chengdu 610052, Sichuan Province, China
Wei-Hao Zhang, Jun Weng, Ze-Hua Li, Kun-Hao Bai, Department of Endoscopy, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Guangdong Provincial Clinical Research Center for Cancer, Guangzhou 510060, Guangdong Province, China
Co-first authors: Di Zhang and Shu-Han Li.
Co-corresponding authors: Ze-Hua Li and Kun-Hao Bai.
Author contributions: Zhang D and Li SH contributed to the literature search, data curation, formal analysis, and the writing including original draft preparation and subsequent review and editing as co-first authors; Zhang WH and Weng J were responsible for the visualization, including the design and production of all figures and tables; Li ZH and Bai KH designed the research, provided research support and revised the manuscript as co-corresponding authors; all authors read and approved the final manuscript.
AI contribution statement: Generative AI was used solely for language editing and polishing of the manuscript. It was not involved in the study design, literature search, study selection, data extraction, evidence synthesis, interpretation of findings, or preparation of scientific conclusions. All AI-assisted edits were carefully reviewed and verified by the authors for accuracy, appropriateness, and consistency with the underlying evidence. The authors take full responsibility for the accuracy, integrity, and content of the final manuscript.
Supported by National Natural Science Foundation of China, No. 82403973.
Conflict-of-interest statement: All authors declare no conflict of interest in publishing the manuscript.
Corresponding author: Kun-Hao Bai, MD, PhD, Associate Chief Physician, Associate Professor, Department of Endoscopy, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Guangdong Provincial Clinical Research Center for Cancer, No. 651 Dongfengdong Street, Yuexiu District, Guangzhou 510060, Guangdong Province, China. baikh@sysucc.org.cn
Received: August 4, 2026
Revised: August 14, 2026
Accepted: October 16, 2026
Published online: December 15, 2026
Processing time: 98 Days and 9.8 Hours
Core Tip

Core Tip: Helicobacter pylori infection may influence gastric cancer immunotherapy outcomes, but clinical evidence remains conflicting – some studies associate positivity with poorer survival, others with enhanced benefit. This review examines the mechanistic pathways underlying this duality, including programmed cell death protein 1/programmed death-ligand 1 regulation, T-cell dysfunction, antigen presentation impairment, myeloid immunosuppression, and microbial ecological shifts. We propose that divergent findings reflect differences in infection definitions, detection methods, tumor subtypes, and treatment settings. Current evidence does not support Helicobacter pylori as a validated predictive biomarker; rather, it represents a context-dependent indicator of the tumor-immune-microbial background. Prospective studies with standardized infection definitions are critically needed.

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