Risk Factors and Outcomes for Metastatic Pancreatic Cancer Diagnosed during Planned Pancreaticoduodenectomy - A National Cohort Study

Abstract

Introduction: Unresectable disease is unfortunately quite often diagnosed during surgery in patients with pancreatic ductal adenocarcinoma (PDAC). The aim was to identify preoperative risk factors for metastatic disease diagnosed at surgical exploration and to investigate and compare survival in resected and nonresected patients. Methods: Patients were identified from the Swedish National Pancreatic and Periampullary Cancer Registry 2010-2018. Predictors of metastatic disease were evaluated with a multivariable logistic regression model, and survival was evaluated with Kaplan-Meier estimates and log-rank tests. Results: In total, 1938 patients with PDAC were scheduled for surgery. An unresectable situation was diagnosed intraoperatively in 399 patients (20.6%), including 234 (12.1%) with metastasized disease. Independent risk factors for metastasis were involuntary weight loss (OR 1.95, 95% CI 1.44-2.63) and elevated CA 19-9 (CA 19-9 35-599 kE/L: OR 2.49, 95% CI 1.49-4.13 and CA 19-9 ≥ 600 kE/L: OR 5.26 95% CI 3.13-8.83). Overall survival was lower among patients with metastasized disease than among patients with a resectable tumor (p<0.001). Conclusion: Involuntary weight loss and an elevation of CA 19-9 are preoperative risk factors for diagnosing metastasized disease during surgical exploration. As expected survival is severely impaired.