Omentectomy vs omentum preservation for advanced gastric cancer: A systematic review and meta-analysis

Currently, gastric cancer is the sixth most prevalent cancer in the world. The recommended treatment for advanced disease is gastrectomy with D2 lymphadenectomy. However, there is no consensus regarding the performance of an omentectomy as part of the treatment. The procedure is considered by some authors to be essential for the elimination of a micrometastasis since cells in the peritoneum prefer growing in milky spots in the omentum. On the other hand, retrospective studies demonstrated that there is the possibility that omentum preservation may not impact patients' overall survival. Therefore, the objective of this review was to quantify the effect of performing an omentectomy to determine whether it is necessary. Medline (PubMed), Embase, Cochrane, ClinicalTrials.gov and LILACS were searched up to September 2022. Selection was restricted to comparative studies in patients with advanced GC (≥T2). The certainty of evidence was assessed with GRADEPro and the risk of bias with ROBINS-I and RoB 2.0. Five cohort studies, and one randomized controlled trial (RCT) were included. The meta-analysis found that there were no significant differences between the procedures for overall survival, relapse-free survival, and peritoneal recurrence. Furthermore, in perioperative outcomes, a significant difference was only found in intraoperative bleeding, which was lower in patients who had their omentum preserved. Therefore, omentum preservation in patients with advanced gastric cancer has been shown to have no inferior results than resection in long-term outcomes.