Is Total Omentectomy Mandatory in T3 and T4a Gastric Cancer for Laparoscopic Distal Gastrectomy?

Background: Despite the lack of strong evidence, total omentectomy (TO) remains the recommended procedure for gastric cancer (GC) for T3 or deeper tumors. Partial omentectomy (PO) has recently become a preferred procedure owing to its simplicity during laparoscopic distal gastrectomy (LDG); however, the oncological role of PO needs to be elucidated. Methods: Overall, 341 patients with T3 or T4a GC who had undergone LDG between 2009 and 2016 were divided into TO (n = 167) and PO (n = 174) groups. Propensity matching was performed with respect to covariance age, sex, T and N stage, tumor size, and degree of tumor differentiation. Clinicopathological characteristics and long-term follow-up data were analyzed for both groups. Results: After successful propensity matching, both groups included 107 patients. In a matched cohort, no significant difference in clinicopathologic features and short-term surgical outcomes was observed between the two groups. Furthermore, no significant difference in relapse-free survival (RFS; p = 0.201) and peritoneal seeding-free survival (PSFS; p = 0.094) was observed. However, tumor recurrence as peritoneal metastasis occurred in 5 (4.7%) patients in the PO group and 13 (12.1%) patients in the TO group. In Cox proportional hazards analysis, omentectomy was not identified as a significant factor for RFS, PSFS, and overall survival; however, advanced N and T4a stage were considered significant factors for RFS and PSFS, respectively. Conclusions: PO may be adopted during the LDG of T3 or T4a GC without definite gross serosal exposure. More large-scale evidence or prospective study is recommended.