Management of gastric cancer peritoneal metastasis: International Gastric Cancer Association GCPM Working Group consensus statements

Abstract

Background Gastric cancer peritoneal metastasis (GCPM) is a common manifestation of advanced gastric cancer, associated with poor prognosis.Methods The International Gastric Cancer Association (IGCA) convened a multidisciplinary working group of 42 global experts from 15 countries to develop a total of 13 consensus statements addressing diagnosis, treatment, and research priorities for GCPM. Using ACcurate COnsensus Reporting Document (ACCORD)-compliant methodology, the group conducted systematic literature searches and applied a structured Delphi process with anonymous Likert-scale voting and a >= 70% consensus threshold to generate and refine consensus statements.Results Consensus was achieved for all 13 statements among the working group during the first Delphi round, with 75-100% of respondents selecting either &apos;strongly agree&apos; or &apos;agree&apos;. Coefficient of variation values were <= 0.23. Polling of a broader group of experts (n = 66), which included members of the working group (n = 21), during a GCPM consensus session at the 16th International Gastric Cancer Congress (IGCC) in 2025 demonstrated agreement for 12 of the 13 statements. This broader group of experts, which had greater representation from medical oncologists, did not reach consensus (52% agreement) on best practice for systemic treatment of patients with GCPM, possibly due to the rapidly evolving developments in this field of metastatic gastric cancer.Conclusion This consensus exercise provides a foundation for globally relevant GCPM management strategies and highlights critical research needed to address significant evidence gaps that will improve patient outcomes. Gastric cancer peritoneal metastasis (GCPM) remains a challenging clinical entity, characterized by poor prognosis and limited therapeutic options. This expert consensus commissioned by the International Gastric Cancer Association represents a crucial advancement of the global collective understanding of GCPM diagnosis, treatment, and research priorities. People with stomach (gastric) cancer often develop spread of the disease to the lining of the abdomen (the peritoneum), which is linked to very poor outcomes. At present, there is no clear international agreement on the best way to diagnose and treat this condition. To address this, the International Gastric Cancer Association brought together experts from around the world to review the evidence and agree on best practice. Using a structured consensus process, the group developed clear recommendations covering diagnosis, treatment options, and future research priorities. These statements aim to improve consistency of care, guide clinical decision-making, and identify areas where further research is urgently needed to improve patient outcomes.