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Background: Although surgical margin status is an established prognostic factor after resection of pancreatic adenocarcinoma, there is no consensus on what constitutes R0 versus R1 resection. R1 resection is defined in North America as the presence of cancer cells at a resection margin and in Europe, as tumor up to 1 mm from a resection margin. We sought to determine the association between width of resection margin and recurrence rates and survival.

Methods: Retrospective analysis was performed of 301 consecutive patients undergoing pancreaticoduodenectomy for adenocarcinoma of the pancreatic head or uncinate process at a single institution over a 20 year period (1991-2011). Adenocarcinomas arising within IPMN or mucinous cystadenomas were excluded. Analyzed variables included age, sex, margin status, use of neoadjuvant therapy, recurrence, and survival. A p value < 0.05 was considered significant.

Results: Of the 301 patients, 102 (34%) received preoperative chemoradiation, and 199 did not. The resection margin was grossly positive (R2) in 4 patients (1%), microscopically positive (R1) in 108 (36%), negative by ≤ 1 mm in 54 (18%), and negative by > 1 mm in 135 (45%). Resection margin status did not correlate with rates of local or distant recurrence (p > 0.05). Overall survival was similar among patients with negative margin width of ≤ 1 mm vs. > 1 mm, with median survival rates of 19 and 21 months, respectively, contrasted with a median survival of 13 months after R1 resection (Figure). Among patients treated with preoperative therapy, median overall survival was 26 and 15 months with negative margin width of > 1 mm and ≤ 1 mm, respectively (p = 0.002). Width of negative margin did not significantly affect survival among patients who did not receive preoperative therapy.

Conclusions: Resection margin status is associated with overall survival but not local recurrence rates. Width of negative margin > 1 mm is a significant prognostic factor among patients treated with neoadjuvant therapy but not among patients undergoing upfront surgery.