Omentum preservation versus complete omentectomy in gastrectomy for gastric cancer (OMEGA trial): study protocol for a randomized controlled trial

Journal article

Background: Potentially curative therapy for locally advanced gastric cancer consists of gastrectomy, usually in combination with perioperative chemotherapy. An oncological resection includes a radical (R0) gastrectomy and modified D2 lymphadenectomy; generally, a total omentectomy is also performed, to ensure the removal of possible microscopic disease. However, the omentum functions as a regulator of regional immune responses to prevent infections and prevents adhesions which could lead to bowel obstructions. Evidence supporting a survival benefit of routine complete omentectomy during gastrectomy is lacking. Methods: OMEGA is a randomized controlled, open, parallel, non-inferiority, multicenter trial. Eligible patients are operable (ASA < 4) and have resectable (≦ cT4aN3bM0) primary gastric cancer. Patients will be 1:1 randomized between (sub)total gastrectomy with omentum preservation distal of the gastroepiploic vessels versus complete omentectomy. For a power of 80%, the target sample size is 654 patients. The primary objective is to investigate whether omentum preservation in gastrectomy for cancer is non-inferior to complete omentectomy in terms of 3-year overall survival. Secondary endpoints include intra- and postoperative outcomes, such as blood loss, operative time, hospital stay, readmission rate, quality of life, disease-free survival, and cost-effectiveness. Discussion: The OMEGA trial investigates if omentum preservation during gastrectomy for gastric cancer is non-inferior to complete omentectomy in terms of 3-year overall survival, with non-inferiority being determined based on results from both the intention-to-treat and the per-protocol analyses. The OMEGA trial will elucidate whether routine complete omentectomy could be omitted, potentially reducing overtreatment. Trial registration: ClinicalTrials.gov NCT05180864. Registered on 6th January 2022.

Authors: Keywani, K; Eshuis, WJ; Borgstein, ABJ; van Det, MJ; van Duijvendijk, P

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: BioMed Central
• Journal: Trials
• Volume: 25
• Issue: 1
• Pages: 588-588
• Article number: 588
• Publication date: 2024-09-04
• Acceptance date: 2024-08-12
• DOI: 10.1186/s13063-024-08396-z
• EISSN: 1745-6215
• ISSN: 1745-6215
• Language: English
• Keywords: Survival; Randomized controlled trial; Gastric cancer; Omentectomy