Overall Survival Advantage of Omentum Preservation Over Omentectomy for Advanced Gastric Cancer: A Systematic Review and Meta‐Analysis

Abstract

Background Since 1910, omentectomy has been an essential component of radical gastrectomy for advanced gastric cancer. However, researchers have recently questioned the benefit of omentectomy in radical gastrectomy. The aim of this meta-analysis was to compare omentectomy and omentum preservation in gastrectomy for advanced gastric cancer in terms of survival outcomes and short-term outcomes. Methods The PubMed, Embase, Web of Science, Cochrane Central Register of Controlled Trials, and ClinicalTrials.gov databases were searched. Studies that compared omentum preservation with omentectomy were included. Overall survival (OS) and relapse-free survival (RFS) were analyzed as primary outcomes. Results Of 3509 records screened, one randomized clinical trial and five propensity-score matched retrospective studies with 1661 patients were selected. Omentum preservation was associated with improved OS (hazard ratio [HR] = 0.757, 95% confidence interval [CI] = 0.603-0.950, P = 0.016, I 2 = 0%), but not with improved RFS (HR = 0.821, 95% CI = 0.668-1.009, P = 0.060, I 2 = 9%) compared with omentectomy for advanced gastric cancer. Furthermore, less blood loss and shorter operation time were found in the omentum preservation group than in the omentectomy group. Additionally, the rate of peritoneal recurrence, the number of harvested lymph nodes, and the incidences of postoperative complications and ileus were comparable in the two groups. Conclusions Basing on the current literature, gastrectomy with omentum preservation was associated with improved OS and short-term outcomes compared with omentectomy for advanced gastric cancer. Further randomized trials are required to confirm the survival benefit of omentum-preserving gastrectomy.

Korean Practice Guidelines for Gastric Cancer 2022: An Evidence-based, Multidisciplinary Approach

“…Seven previous meta-analyses studied the oncologic feasibility of PO [ 326 327 328 329 330 ]. All the meta-analyses showed that PO was not inferior to TO regarding OS and relapse-free survival.…”

Gastrectomy with or without Complete Omentectomy for Advanced Gastric Cancer: A Meta-Analysis

“…Peritoneal recurrence stood out, representing 36-45% of all kinds [38]. Omentum turned out as the most involved peritoneal site [6,7,14,[22][23][24][25][26].…”

“…Despite omental tissue's protumoral properties, authors are still debating on the need to perform CO, in addition to gastrectomy and D2 lymphadenectomy for GC [6,7,14,[22][23][24][25][26]. Analyses of major guidelines in GC treatment clearly explained this topic.…”

“…Several mainly retrospective observational studies analyzed the role of complete omentectomy (CO) in addition to radical gastrectomy in GC patients [16][17][18][19][20][21]. Given the presence of significant bias in the aforementioned studies, different meta-analyses have been developed in order to improve the present evidence [6,7,14,[22][23][24][25][26]. Such meta-analyses demonstrated that gastrectomy without CO gives similar, even better short-and longterm results than gastrectomy with CO, although many of those studies also included populations with early gastric cancer (EGC) [6,7,14,[22][23][24][25][26].…”

“…Given the presence of significant bias in the aforementioned studies, different meta-analyses have been developed in order to improve the present evidence [6,7,14,[22][23][24][25][26]. Such meta-analyses demonstrated that gastrectomy without CO gives similar, even better short-and longterm results than gastrectomy with CO, although many of those studies also included populations with early gastric cancer (EGC) [6,7,14,[22][23][24][25][26]. At present, outcomes of just one randomized controlled trial (RCT) are available [27], while two other RCTs are being investigated [28,29].…”