Background: Many patients with borderline resectable/locally advanced pancreatic ductal adenocarcinoma (borderline resectable [BR]/locally advanced [LA] pancreatic ductal adenocarcinoma [PDAC]) undergoing resection will have positive resection margins (R1), which is associated with poor prognosis. It might be useful to preoperatively predict the margin (R) status.
Methods: Data from patients with BR/LA PDAC who underwent a pancreatectomy between 2008 and 2018 at Brigham and Women's Hospital were retrospectively reviewed. Logistic regression analysis was used to evaluate the association between R status and relevant preoperative factors. Significant predictors of R1 resection on univariate analysis (P < .1) were entered into a stepwise selection using the Akaike information criterion to define the final model.
Results: A total of 142 patients with BR/LA PDAC were included in the analysis, 60(42.3%) had R1 resections. In stepwise selection, the following factors were identified as positive predictors of an R1 resection: evidence of lymphadenopathy at diagnosis (OR = 2.06, 95% CI: 0.99-4.36, P = .056), the need for pancreaticoduodenectomy (OR = 3.81, 96% CI: 1.15-15.70, P = .040), extent of portal vein/superior mesenteric vein involvement at restaging (<180°, OR = 3.57, 95% CI: 1.00-17.00, P = .069, ≥180°, OR = 7,32, 95% CI: 1.75-39.87, P = .010), stable CA 19-9 serum levels (less than 50% decrease from diagnosis to restaging, OR = 2.27, 95% CI: 0.84-6.36 P = .107), and no preoperative FOLFIRINOX (OR = 2.17, 95% CI: 0.86-5.64, P = .103). The prognostic nomogram based on this model yielded a probability of achieving an R1 resection ranging from <5% (0 factors) to >70% (all 5 factors).
Conclusions: Relevant preoperative clinicopathological characteristics accurately predict positive resection margins in patients with BR/LA PDAC before resection. With further development, this model might be used to preoperatively guide surgical decision-making in patients with BR/LA PDAC.
Keywords: borderline resectable pancreatic ductal adenocarcinoma; locally advanced pancreatic ductal adenocarcinoma; neoadjuvant therapy; nomogram; surgical margin prediction.