The involvement of the hepatic artery is a risk factor for unresectability after neoadjuvant treatment in borderline pancreatic adenocarcinoma.

Introduction: Borderline Resectable Pancreatic Ductal Adenocarcinoma (BR-PDAC) benefits from neoadjuvant treatment (NAT) with the intent of surgical salvage in the absence of disease progression during chemotherapy (CT) or chemoradiotherapy (CRT). Scarce literature exists about prognostic factors of resectability at the time of diagnosis or during neoadjuvant treatment, especially regarding vascular relationships.

Materials: We reviewed our prospective BR-PDAC cohort to determine resectability predictors. We collected data about clinical baseline characteristics, vessels' involvement, type of NAT, CA19-9 evolution, and radiological outcome. We performed a descriptive analysis and a logistic regression model to define resectability predictors; we finally compared overall survival (OS) and progression-free survival (PFS) for those predictors.

Results: One hundred patients started NAT, with a resection rate of 44 % (40 pancreaticoduodenectomies, 4 distal pancreatectomies). The most frequent vessel relationship was the abutment of the superior mesenteric artery (44 %), and 26 patients had ≥2 vessels involved. Prognostic factors of resectability were CA19-9 response >10 % (OR 3.07, p = 0.016) and Hepatic Artery involvement (OR 0.21, p = 0.026). Median overall survival was better for CA19-9 responders than for non-responders (20.9 months and 11.8 months respectively, p < 0.001), and similar to normalized CA19-9 (25.0 months, p = 0.48). There were no differences in terms of OS or PFS with the involvement of the HA (17.7 vs 17.1 months, p = 0.367; and 8.7 vs 12.0 months, p = 0.267).

Conclusion: The involvement of the Hepatic Artery seems to confer a worse prognosis regarding resectability. A decrease of only >10 % of CA19-9 is a predictive factor for resectability and better overall and progression-free survival.