Role of anti-stromal polypharmacy in increasing survival after pancreaticoduodenectomy for pancreatic ductal adenocarcinoma.

AIM To investigate the survival impact of common pharmaceuticals, which target stromal interactions, following a pancreaticoduodenectomy for pancreatic ductal adenocarcinoma. METHODS Data was collected retrospectively for 164 patients who underwent a pancreaticoduodenectomy for pancreatic ductal adenocarcinoma (PDAC). Survival analysis was performed on patients receiving the following medications: angiotensin-converting enzyme inhibitors (ACEI)/angiotensin II receptor blockers (ARB), calcium channel blockers (CCB), aspirin, and statins. Statistical analysis included Kaplan-meier survival estimates and cox multivariate regression; the latter of which allowed for any differences in a range of prognostic indicators between groups. Medications showing a significant survival benefit were investigated in combination with other medications to evaluate synergistic effects. RESULTS No survival benefit was observed with respect to ACEI/ARB (n = 41), aspirin or statins on individual drug analysis (n = 39). However, the entire CCB group (n = 26) showed a significant survival benefit on multivariate cox regression; hazard ratio (HR) of 0.475 (CI = 0.250-0.902, P = 0.023). Further analysis revealed that this was influenced by a group of patients who were taking aspirin in combination with CCB; median survival was significantly higher in the CCB + aspirin group (n = 15) compared with the group taking neither drug (n = 98); 1414 d vs 601 d (P = 0.029, log-rank test). Multivariate cox regression revealed neither aspirin nor CCB had a statistically significant impact on survival when given alone, however in combination the survival benefit was significant; HR = 0.332 (CI = 0.126-0.870, P = 0.025). None of the other medications showed a survival benefit in any combination. CONCLUSION Aspirin + CCB in combination appears to increase survival in patients with PDAC, highlighting the potential clinical use of combination therapy to target stromal interactions in pancreatic cancer.