TTP2.14 Factors associated with R1/R2 resection in patients undergoing right hemicolectomy and its impact on long-term outcomes

Introduction The impact of resection status on the peri-operative outcome following right hemicolectomy is unclear. The aim of this study was to examine factors associated with R1 resection in patients undergoing right hemicolectomy (curative intent) for colon cancer in NHS Tayside. Method A prospective observational cohort study of patients undergoing both emergency and elective right-sided hemicolectomy between 2010-2020 was conducted. Each patient had subsequently followed up for complications and survival and the impact of resection status on outcome were determined. Results A total of 892 patients were included (M:F 0.8:1, median age, 71; emergency:elective, 152:740) and there were 48 patients with R1 resection and 8 patients with R2. Positive lymph nodes were the only variable associated with R1/R2 (OR=2.36, p=0.043). R1/R2 was not associated with inpatient mortality (OR=1.12, p=0.856), anastomotic leak (OR=1.05, p=0.877) or readmission (OR=0.852, p=0.678). Median survival in the R1/R2 group was 35.7 months compared to 128 months (p<0.001). R1/R2 was independently negatively associated with mortality in multivariate survival analysis (HR 1.57, p=0.017) Discussion Few factors can help predict R1/R2 margins but patients with positive lymph nodes are at high risk. R1/R2 resections have no significant impact on short term outcomes or complications but significantly reduce long-term survival.