Long-term outcomes of omentum-preserving versus resecting gastrectomy for locally advanced gastric cancer with propensity score analysis

Yusuke Sakimura,Noriyuki Inaki,Shinichi Kadoya,Hiroyuki Bando,Toshikatsu Tsuji

doi:10.1038/s41598-020-73367-8

Abstract

Omentectomy is conducted for advanced gastric cancer (AGC) patients as radical surgery without an adequate discussion of the effect. This study was conducted to reveal the impact of omentum-preserving gastrectomy on postoperative outcomes. AGC patients with cT3 and 4 disease who underwent total or distal gastrectomy with R0 resection were identified retrospectively. They were divided into the omentum-preserved group (OPG) and the omentum-resected group (ORG) and matched with propensity score matching with multiple imputation for missing values. Three-year overall survival (OS) and 3-year relapse-free survival (RFS) were compared, and the first recurrence site and complications were analysed. The numbers of eligible patients were 94 in the OPG and 144 in the ORG, and after matching, the number was 73 in each group. No significant difference was found in the 3-year OS rate (OPG: 78.9 vs. ORG: 78.9, P = 0.54) or the 3-year RFS rate (OPG: 77.8 vs. ORG: 68.2, P = 0.24). The proportions of peritoneal carcinomatosis and peritoneal dissemination as the first recurrence site and the rate and severity of complications were similar in the two groups. Omentectomy is not required for radical gastrectomy for AGC.

Highlights

Omentectomy is conducted for advanced gastric cancer (AGC) patients as radical surgery without an adequate discussion of the effect
The OMEGA trial indicated that the incidence of metastases in the greater omentum is low, and that metastases are associated with advanced disease and non-radical features[13]
In terms of the complications and the first recurrence site, there were no significant differences between the two groups (Table 3)

Summary

Introduction

Omentectomy is conducted for advanced gastric cancer (AGC) patients as radical surgery without an adequate discussion of the effect. Surgical resection of the primary tumour can lead to radical treatment; discussions about less invasive procedures and functional preservation for advanced gastric cancer (AGC) surgery have arisen r ecently[2,3,4]. Japanese gastric cancer treatment guidelines indicate that removal of the greater omentum is usually recommended in standard gastrectomy for T3 or deeper tumours[10]. One propensity-matched retrospective cohort study investigated the long-term outcomes of omentum preservation and concluded that omentum-preserving gastrectomy for advanced gastric cancer (ACG) did not affect relapse and survival rates[14].

Results

Conclusion