Impact of Neoadjuvant Therapy in Resected Pancreatic Ductal Adenocarcinoma of the Pancreatic Body or Tail on Surgical and Oncological Outcome: A Propensity-Score Matched Multicenter Study.

Background: Several studies have suggested a survival benefit of neoadjuvant therapy (NAT) for pancreatic ductal adenocarcinoma (PDAC) in the pancreatic head. Data concerning NAT for PDAC located in pancreatic body or tail are lacking.
Methods: Post hoc analysis of an international multicenter retrospective cohort of distal pancreatectomy for PDAC in 34 centers from 11 countries (2007-2015). Patients who underwent resection after NAT were matched (1:1 ratio), using propensity scores based on baseline characteristics, to patients who underwent upfront resection. Median overall survival was compared using the stratified log-rank test.
Results: Among 1236 patients, 136 (11.0%) received NAT, most frequently FOLFIRINOX (25.7%). In total, 94 patients receiving NAT were matched to 94 patients undergoing upfront resection. NAT was associated with less postoperative major morbidity (Clavien-Dindo ≥ 3a, 10.6% vs. 23.4%, P = 0.020) and pancreatic fistula grade B/C (9.6% vs. 21.3%, P = 0.026). NAT did not improve overall survival [27 (95% CI 14-39) versus 31 months (95% CI 19-42), P = 0.277], as compared with upfront resection. In a sensitivity analysis of 251 patients with radiographic tumor involvement of splenic vessels, NAT (n = 37, 14.7%) was associated with prolonged overall survival [36 (95% CI 18-53) versus 20 months (95% CI 15-24), P = 0.049], as compared with upfront resection.
Conclusion: In this international multicenter cohort study, NAT for resected PDAC in pancreatic body or tail was associated with less morbidity and pancreatic fistula but similar overall survival in comparison with upfront resection. Prospective studies should confirm a survival benefit of NAT in patients with PDAC and splenic vessel involvement.