Evaluation of preoperative prognostic factors in patients with resectable pancreatic ductal adenocarcinoma

Objective: Upfront surgery is the standard treatment for resectable pancreatic ductal adenocarcinomas (R-PDACs); however, these tumors often recur. We investigated the factors governing recurrence and prognosis in patients with R-PDAC. Methods: We analyzed 359 patients who underwent upfront surgery for R-PDAC between 2000 and 2016, and evaluated the relationship between clinicopathological factors and recurrence/outcomes. Results: The rate of recurrence was 74% while the median time to recurrence was 1.2 years. On multivariate analysis, carbohydrate antigen 19-9 (CA19-9) >37 U/mL (hazard ratio [HR]: 2.02), tumor size >2.6 cm (HR: 1.50), pathological grade 3 (HR: 2.58), lymph node metastasis (LNM; HR: 1.65), residual tumor (HR: 1.47) and forgoing adjuvant chemotherapy (HR: 1.31) were risk factors for a shorter recurrence-free survival; the median survival time (MST) was 2.8 years. On multivariate analysis, CA19-9 > 37 U/mL (HR: 1.99), tumor size >2.6 cm (HR: 1.43), pathological grade 3 (HR: 2.93), pathological portal vein invasion (HR: 1.48), LNM (HR: 1.79) and forgoing adjuvant chemotherapy (HR: 1.39) were risk factors for shorter disease-specific survival intervals. When examining outcomes according to preoperatively measurable factors (CA19-9 > 37 U/mL and tumor size >2.6 cm), the median time to recurrence and MSTs of patients with none (n = 83), one (n = 112) and both (n = 164) risk factors were 3.2, 1.8 and 0.8 years; and 7.2, 4.0 and 1.7 years, respectively. Conclusions: CA19-9 > 37 U/mL and tumor size >2.6 cm were preoperative independent risk factors for early recurrence and poor outcomes in patients with R-PDAC. Therefore, preoperative treatment should be considered for such patients.