Background Microscopically non-radical (R1) oesophageal cancer resection has been associated with worse survival. The aim of this study was to identify risk factors for R1 resection and to investigate how this affects long-term survival. Methods The Swedish National Register for Oesophageal and Gastric Cancer was used to identify all patients who underwent oesophageal cancer resection with curative intent between 2006 and 2017. Risk factors for R1 resection were assessed by multivariable logistic regression analysis, and factors predicting 5-year survival identified by multivariable Cox regression. Results The study included 1460 patients. Surgical margins were involved microscopically in 142 patients (9.7 per cent). The circumferential resection margin was involved in 114 (7.8 per cent), the proximal margin in 53 (3.6 per cent), and the distal margin in 29 (2.0 per cent). In 30 specimens (2.1 per cent), two or all three margins were involved. Independent risk factors for R1 resection were male sex, low BMI, absence of neoadjuvant treatments, and clinical T4 disease. The 5-year survival rate for the entire cohort was 42.2 per cent, but only 18.0 per cent for those who had an R1 resection. Independent risk factors for death within 5 years of resection were male sex, age above 60 years, normal BMI, ASA fitness grade III, intermediate-level education, R1 resection (hazard ratio 1.80, 95 per cent c.i. 1.40 to 2.32), clinical T3 disease, and clinical lymph node metastasis. Conclusion R1 resection is common and predicts poor 5-year survival. Absence of neoadjuvant treatment is a risk factor for R1 resection.

Aim To identify potential risk factors for a microscopically non-radical esophageal cancer resection (R1) and investigate how such a resection affects long-term survival. Background & Methods Esophageal cancer resections that are considered R1 have been associated with worse survival. The Swedish National Register for Esophageal and Gastric Cancer includes information on all esophageal cancer resections in Sweden. All patients having undergone esophageal resection with curative intent 2006-2017 were included. Risk factors for R1 resection were assessed through logistic regression. Factors predicting five-year survival were assessed through Cox-regression, adjusted for T-stage, N-stage, age and R-status. Results The study included 1,504 patients. The margins were microscopically involved in 146 patients (10%). Of these the circumferential margin was involved in 115 (8%). The proximal margin was involved in 55 patients (4%) and the distal in 30 (2%). In 54 (4%) specimens two margins were involved. Independent risk factors for R1-resection were absence of neoadjuvant treatment and clinical T3 stage or higher. The 5-year survival for the entire cohort was 41%, but only 19% for those with an R1 resection. Independent risk factors for death within 5-year from resection were regional lymph node metastasis (Hazard Ratio (HR) 2.6 (95% CI 2.2-3.1), histopathological stage T3 or higher (HR 1.2 95% CI 1.1-1.5), age above 60 years and R1-resection (HR 1.6 95% CI 1.4-2.0) Conclusion Involved margin in the resected specimen is an independent risk factor predicting worse 5-year survival. Besides striving for adequate surgical margins, the rate of R1-resections could be decreased through neoadjuvant treatment in fit patients.