Length of the proximal resection margin and survival after surgery for oesophageal cancer

Abstract Background While tumour-free (R0) margins are essential in oesophageal cancer surgery, the ideal length of the proximal resection margin remains unclear. Although longer margins may improve oncological outcomes, they can increase surgical complexity and morbidity. Current evidence is limited and inconsistent, mostly based on small retrospective studies. This population-based cohort study aimed to assess the association between proximal resection margin length and 5-year mortality following oesophagectomy for oesophageal cancer. Methods This binational, population-based cohort study included 1,830 patients who underwent curatively intended oesophagectomy with tumour-free margins for oesophageal cancer in Sweden or Finland between 2006 and 2020. The main exposure was the length of the proximal resection margin, categorized as 0.1–<2.0 cm, 2.0–<5.0 cm, 5.0–<8.0 cm, and ≥8.0 cm. The outcomes were all-cause and disease-specific 5-year mortality. Multivariable Cox regression provided adjusted hazard ratios (HR) with 95% confidence intervals (CI). Results There was a gradual decrease in the risk of 5-year mortality outcomes with increasing proximal resection margin lengths up until the category 5.0 to <8.0 cm, with HR 0.83 (95% CI 0.68-1.01) for all-cause mortality and HR 0.80 (95% CI 0.65–0.98) for disease-specific mortality. A longer resection margin (>8.0 cm) did not further decrease the all-cause 5-year mortality (HR 0.87, 95% CI 0.70-1.09) or disease-specific 5-year mortality (HR 0.85, 95% CI 0.67-1.07). Conclusions A proximal resection margin of 5 to 8 cm may be appropriate to optimize the chance of 5-year survival in oesophageal cancer patients who undergo oesophagectomy, but further research is necessary to confirm its applicability.