Comparing outcomes in recurrent versus de novo metastatic pancreatic adenocarcinoma: A retrospective study

Background: A majority of patients undergoing curative intent surgery for pancreatic ductal adenocarcinoma (PDAC) will unfortunately develop recurrent disease. Optimal management of these patients remains unclear. In this study, we evaluated clinical outcomes of patients with recurrent PDAC who received systemic therapy and compared outcomes to patients with de novo metastatic PDAC. Methods: : Patients diagnosed with metastatic PDAC between 2014 and 2019 were included using a real-world database. Patients were characterized as either de novo or recurrent based on the date of metastatic diagnosis and history of surgical resection. Overall survival (OS) was summarized within groups via Kaplan-Meier survival estimates and compared using Cox proportional hazards models. Results: : We included 5170 patients with metastatic PDAC, of which 1101 (21.3%) were classified as having recurrent disease. Median OS for the recurrent group was significantly greater at 10.8 m (95% CI 9.9-11.7) than in the de novo group at 7.3 m (95% CI 7.0-7.7, p< 0.001). We did not observe a significant difference in OS based on when patients recurred after surgery: 10.0 m (95% CI 8.7-11) within six months of surgery versus 11.6 m (95% CI 10-12, p=0.256) greater than six months from surgery. Conclusions: : These data support the inclusion of patients with recurrent PDAC in clinical trials for advanced disease, including those who develop recurrent disease within six months of surgery. Due to observed differences in survival, randomization should be stratified by disease presentation (recurrent vs de novo ).