Pancreatic adenocarcinoma: A simple CT score for predicting margin-positive resection in patients with resectable disease.

BACKGROUND: Negative-margin status is a prognostic indicator for long-term survival following curative intent resection for pancreatic adenocarcinoma. Patients at increased risk for positive-margin resections may benefit from neoadjuvant chemotherapy prior to resection.

METHODS: We retrospectively analyzed preoperative computed-tomography (CT) scans in 108 consecutive patients that underwent curative intent resection for a resectable pancreatic ductal adenocarcinoma from 2009 to 2016 in two academic hospitals. Two radiologists independently staged the tumor, including tumor location, size, and tumor-to-superior mesenteric/portal vein (SMV/PV) contact. Uni and multivariate analysis were performed to identify independent predictors of an R1 resection.

RESULTS: Twenty-nine patients had an R1 resection (26.9%). Tumor size, location, and presence of tumor-to-SMV/PV contact were significantly associated with an R1 resection. In multivariate analysis, the independent parameters associated with resection status were: tumor size (R2 =9.7), and tumor location (neck R2 =6.6; pancreaticoduodenal interface R2 =4.4; uncinate process R2 =4.1), but not tumor-to-SMV/PV contact (R2 =0.1, p=0.7). A simple CT score was built based on tumor size and location. Patients with an R0 resectability score ≥3, i.e. patients with tumor size ≥30mm (except when tumor location is at the pancreatico-duodenal interface) or patients with tumor size ≥20mm AND tumor located in the uncinate process or neck, were at high-risk of an R1 resection (AUC, 0.82; sensitivity, 79%; specificity, 76%). This score also showed good diagnostic performances for predicting an R1 resection involving the medial resection margin only (AUC, 0.85).

CONCLUSIONS: A simple score based on tumor location and size can accurately predict patients at high-risk of an R1 resection.