The Short-Term Outcomes From Top-G Trial: Ramdomized Phase Ii Noninferiority Trial Comparing Gastrectomy With Omentectomy And Omentum Preserving Gastrectomy For Advanced Gastric Cancer

285 Background: A complete resection of the omentum has been believed as a standard procedure for advanced gastric cancer. However, there was no evidence for survival significance of omentectomy. Therefore, we conduct the Phase II trial (TOP-G trial) comparing gastrectomy with omentectomy and omentum preserving gastrectomy. Here, we present the short-term outcomes which was a secondary endpoint of TOP-G trial. Methods: Enrollment criteria included histologically confirmed cT2-4a and N0-2 gastric adenocarcinoma. The extent of nodal dissection was performed based on the Gastric Cancer Treatment Guidelines in Japan. All procedure was performed through laparotomy. Laparoscopic approach was not accepted. Surgical outcomes morbidity, and mortality were compared between gastrectomy with omentectomy group (group A) and omentum preserving gastrectomy group (group B). Postoperative complication was evaluated with Clavien-Dindo classification. Results: A total of 251 patients were randomly assigned to group A (n = 125) or group B (n = 126) between April 2011 and October 2018. After excluding patients who received bypass or no surgery, 246 patients were analyzed as actual treatment group. There was no difference between two groups in patient characteristics and pathological findings. There was no difference in operation time (median 244 vs 204 min, p = 0.156) and in blood loss (median 260 vs. 210 ml, p = 0.371). Median number of totally retrieved lymph nodes was similar (median 36 vs. 37, p = 0.758). There was no difference in the incidence of any postoperative complication (28.9% vs. 25.8%, p = 0.584). There was no mortality in both groups. Conclusions: Omentum preserving gastrectomy for advanced gastric cancer was similar short-term outcomes with gastrectomy with omentectomy. Clinical trial information: UMIN000005421.