Omental preservation versus omentectomy in curative-intent gastrectomy for gastric cancer: Swedish population-based cohort study.

[BACKGROUND] Omentectomy has traditionally been performed in gastric cancer surgery, but omental preservation has become increasingly common. It is unclear whether omentectomy leads to additional survival benefit compared with omental preservation. This nationwide population-based cohort study aimed to assess survival and surgical outcomes comparing omental preservation to omentectomy in curative-intent gastrectomy.

[METHODS] Patients were identified from the Swedish National Registry for Oesophageal and Gastric Cancer with inclusion between 2006 and 2022. The primary endpoint was overall survival assessed by a multivariable Cox proportional hazards model, adjusted for age, sex, American Society of Anesthesiologists physical status score, clinical T and N stage, type of gastrectomy, surgical approach, extent of lymphadenectomy, neoadjuvant chemotherapy, surgery year and regional cancer centre. Secondary endpoints were surgical outcomes including tumour-free resection margins, lymph node yield and postoperative complications.

[RESULTS] A total of 1615 patients were included, 517 (32.0%) underwent gastrectomy with omental preservation, and 1098 (68.0%) underwent gastrectomy with omentectomy. Overall survival after omental preservation was similar compared with omentectomy in the multivariable Cox model (HR 1.00, 95% c.i. 0.83 to 1.20; P = 0.967). Omental preservation also had similar surgical outcomes including lymph node yield and postoperative morbidity rate, compared with omentectomy.

[CONCLUSIONS] Omental preservation was similar to omentectomy in terms of overall survival and surgical outcomes. The results suggest that omentectomy can safely be omitted in curative-intent gastrectomy for gastric cancer.