LAUSR

395 Background: Neoadjuvant therapy (NAT) for pancreatic ductal adenocarcinoma (PDAC) is associated with improved overall survival (OS), and this has led to its rising use. The aim of this study was to evaluate the correlation between use of NAT and OS among patients with PDAC. Methods: This population-level study evaluated the Spearman correlation between the annual proportion of patients receiving NAT and the annual 1-year and 5-year OS, respectively, using the 2004-2015 National Cancer Database. Annual 1-year and 5-year OS was calculated from year of diagnosis using Kaplan-Meier survival analysis. All patients with a confirmed diagnosis of PDAC (histology code 8500), without any metastasis, and who underwent an R0 or R1 resection were included. Results: A total of 18,852 patients (median age 67 (IQR 60–74); 49.4% female) with PDAC underwent an R0/R1 resection from 2004 to 2015. Among these patients, there was a significantly positive correlation between the proportion of patients who received NAT (12.1%; n = 2,133) and 1-year OS (Spearman’s rho = 0.9091; P = 0.0001) and 5-year OS (Spearman’s rho = 0.7833; P = 0.01), respectively. Patients who underwent R0 resection (n = 14,547; median age 67 (IQR 60-74); 49.9% female) had a significantly positive correlation between those who received NAT (13.1%; n = 1,773) and 1-year OS (Spearman’s rho = 0.8818; P = 0.0003) and 5-year OS (Spearman’s rho = 0.7333; P = 0.02), respectively. Among 9,142 patients who had upfront resectable disease with R0 resection margin status (median age 68 (IQR 60–75); 49.8% female), there was a significantly positive correlation between proportion of patients who received NAT (9.1%; n = 781) and 1-year OS (Spearman’s rho = 0.7273; P = 0.01) and 5-year OS (Spearman’s rho = 0.8000; P = 0.0096), respectively. Conclusions: Between 2004 and 2015 there has been an increase in the use of NAT for patients with PDAC. Concurrently, the OS has also increased during this time period. This study demonstrates that there is a statistically significant and positive correlation between the proportion of patients with R0/R1 resected PDAC who received NAT and 1-year OS and 5-year OS, respectively.