Background: The limited efficacy of chemotherapy in improving survival in pancreatic ductal adenocarcinoma (PDAC) necessitates the exploration of novel strategies to overcome treatment resistance.

Objectives: This study aimed to investigate the impact of combining renin-angiotensin system (RAS) blockers with chemotherapy on survival outcomes in patients with PDAC.

Design: Patients with PDAC were enrolled in the retrospective study.

Methods: We analyzed patients with PDAC (n = 384) at our institution between 2014 and 2021. Survival outcomes, including event-free survival (EFS) and overall survival (OS), were analyzed according to the concomitant use of RAS blockers.

Results: Among the 384 patients in the study, 70 (18.2%) concomitantly received angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs). Patients in the ACEI/ARB group, characterized by older age and more comorbidities, displayed a significantly superior 12-month EFS rate (22.86% versus 13.69%, p = 0.008) compared to the non-ACEI/ARB group, while OS remained similar between the groups. In the multivariate analysis, the use of ACEI/ARB was associated with better 12-month EFS (hazards ratio = 0.71, 95% confidence interval: 0.52-0.96; p = 0.024). Poor performance, advanced disease status, and higher CA19-9 levels were associated with poor survival outcomes.

Conclusion: Concomitant use of ACEIs/ARBs in patients with pancreatic cancer resulted in significantly better 12-month EFS. Age, performance status, disease status, and higher CA19-9 levels were independent predictors of survival. The combination strategy might provide better treatment outcomes in patients with PDAC.