Negative resection margins (R0) for pancreatic ductal adenocarcinoma (PDAC) have traditionally been defined as 0mm in North American centres. However, it has been advocated that a more conservative definition of R0 resection be employed given the microscopically diffuse nature of PDAC at its borders. We conducted a retrospective cohort study of adult patients undergoing pancreaticoduodenectomy between 2010-2015 to evaluate the effect of resection margin distance (0mm, 0 to ≤2mm vs >2mm) on overall and disease free survival. Mean survival times were calculated. Kaplan Meier curves were constructed and evaluated using the log rank test. 96 deaths were observed in 136 patients over 207.5 person years. Mean follow-up time was 18.3 months. 76 patients were noted to have a recurrence. 48 patients (35%) were found to have involved margins. Both overall and disease free survival were found to be statistically different in patients with 0mm margins compared to those patients whose closest margin was measured to be 0 to ≤2mm and >2mm (log rank = 0.001 and 0.004, respectively). Mean overall survival was 14.7 months (95% confidence interval (CI) 11.9–17.5), 27.3 months (95% CI 20.9–33.8), 32.7 months (95% CI 22.3–43.0) and mean disease free survival was 13.2 months (95% CI 10.5–16.0), 26.0 months (95% CI 18.7–33.3), 33.0 months (95% CI 23.0–43.0) in the 0mm, 0 to ≤2mm and >2mm groups, respectively. 7 patients survived 5 years post-operatively; of those, none had 0mm margins, 4 had a margin between 0 to ≤2mm and 3 had a margin >2mm. Given the high incidence of patients with involved resection margins following pancreaticoduodenectomy and the associated negative outcomes, greater consideration should be given to neoadjuvant therapy for treatment of PDAC in order to optimize the likelihood of complete resection and select patients most likely to benefit from surgery.

The effect of resection margin distance on survival following pancreaticoduodenectomy for pancreatic ductal adenocarcinoma. How close is too close?