Risk factors and outcomes for patients with pancreatic cancer undergoing surgical exploration without resection due to metastatic disease : A national cohort study

Background: Unresectable disease is sometimes diagnosed during surgery in patients with pancreatic ductal adenocarcinoma (PDAC). This study aimed to identify preoperative risk factors for metastatic disease diagnosed at surgical exploration and to investigate and compare survival in resected and non-resected 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 = 1.72; 95% CI: 1.27-2.33) and elevated carbohydrate antigen 19-9 (CA19-9) (35-599 U/mL, OR = 1.79, 95% CI: 1.11-2.89; ≥ 600 U/mL, OR = 3.24, 95% CI: 2.04-5.17). Overall survival was lower among patients with metastasized disease than that among patients with a resectable tumor (P < 0.001). Conclusions: Involuntary weight loss and an elevation of CA19-9 are preoperative risk factors for diagnosing metastasized disease during surgical exploration