263 Background: Readmission that occurs within a short period after discharge of initial gastrectomy for gastric cancer may affect the patient's prognosis and adversely affect the overall treatment courses. Among the possible related factors, the Influence between postoperative home-health-care support and readmission has been studied in various diseases, but the relationship with gastric cancer patients was limited. The purpose of the study was to investigate the risk factors associated with readmission after gastrectomy and home-health-care support on readmission. Methods: A total of 2,605 patients who underwent curative gastrectomy with lymphadenectomy between 2013 and 2020 were retrospectively reviewed. Chi-squared tests were performed to evaluate for potential risk factors for readmissions. A multivariate regression analysis was performed to identify independent predictors, including home-health-care support. Results: Among 2,605 undergoing gastrectomy, 134 (5.18%) had suffered unplanned readmission within postoperative 60-days (0̃50days). There was no significant annual difference in the postoperative length of hospital stay and the proportions of the home-health-care support during the study period, but the readmission rate decreased significantly by 0.646% annually from 7.88% in 2013 to 1.22% in 2020 (P = 0.023). The readmission group had a higher Eastern Cooperative Oncology Group (ECOG) score, a significantly higher rate of open and total gastrectomy, and a higher rate of postoperative complications and severe postoperative complications (C-D grade≥3a). Multivariable analysis demonstrated that the occurrence of severe postoperative complications (odds ratio (OR) 9.306, p < 0.001) and the presence of home-health-care support (OR 1.725, p = 0.009) were independently associated with readmission. However, age, sex, ECOG, preoperative body mass index, preoperative comorbidity including cardiovascular comorbidity, surgery-related factors, and the disease severity had no significant effect on readmission. Among the significant factors, home-health-care support showed the effect of reducing the time span between the index discharge and readmission (p = 0.049) and the length of the second hospitalization (p = 0.029). Conclusions: Readmission after radical gastrectomy is affected by various factors. Among them, home-health-care support has the merits of reducing the length of hospital stay for readmission by identifying patients in need of hospitalization at an early stage through direct face-to-face contact with the patient. It is necessary to establish an appropriate strategy to improve the quality of postoperative courses for high-risk patients of readmission.

279 Background: Peritoneal recurrence of gastric cancer after curative surgical resection is common and portends a poor prognosis. Preliminary studies suggest extensive intraoperative peritoneal lavage (EIPL) may reduce the risk of peritoneal recurrence and improve survival. We sought to perform a randomized phase III study to definitively establish the role of performing EIPL after gastrectomy. Methods: This is a prospective, open-label, phase 3 multicentre randomised controlled trial involving 22 hospitals from Korea. China, Japan, Malaysia and Singapore. Patients aged between 21 to 80 years with cT3/4 stomach cancer undergoing curative resection were randomized to either surgery and EIPL (lavage with 10 litres of saline) or surgery alone. Comparison of DFS and OS were made via log-rank test. The cumulative incidence of peritoneal recurrence was compared using competing risks approach. All analyses were performed based on intention-to-treat. Results: Between March 2015 to August 2018, 800 patients were randomly assigned to surgery alone ( n= 402) or EIPL ( n= 398). Based on a median follow-up duration of 29 months, the 3-year cumulative incidence of all-cause mortality was 23.1% and 23.3% for EIPL and surgery alone respectively (hazard ratio [HR] = 1.09, 95% CI: 0.78 to 1.52, p = 0.615). Similarly, the 3-year cumulative incidence of recurrence were 28.0% and 25.9% respectively (HR = 1.01, 95% CI: 0.74 to 1.37, p = 0.947), and 7.9% and 6.6% respectively for peritoneal recurrence (Subdistribution HR = 1.33, 95% CI: 0.73 to 2.42, p = 0.347). Overall, the risk of adverse events was higher in EIPL as compared to surgery alone (relative risk = 1.58, 95% CI 1.07 to 2.33, p = 0.019). The most common adverse events were anastomotic leak, bleeding and intra-abdominal abscess. At the planned third interim analysis on 28 August 2019, the predictive probability of achieving even a 5% difference in 3-year OS in favour of EIPL at final analysis was < 0.4%. The trial was thus recommended to terminate on the basis of futility. Conclusions: EIPL does not show any survival benefit compared with surgery alone and is not recommended for patients undergoing curative gastrectomy for cancer. Clinical trial information: NCT02140034.