Chronologic changes in clinical and survival features of pancreatic ductal adenocarcinoma since 2000: A single-center experience with 2,029 patients

Background: To identify chronologic changes in clinical and survival features of pancreatic ductal adenocarcinoma based on diagnosis and treatment strategy development since 2000. Methods: Among 2,029 patients enrolled in this study, 746 and 1,283 were treated between 2000 and 2009 (group 1) and between 2010 and 2016 (group 2), respectively. We used patient clinicopathologic, biologic, and molecular factors to assess the prognostic factors. Results: Group 2 had a better survival outcome than group 1 (median survival time: 24.9 versus 18.4 months; 5-year survival rate: 27.6% versus 22.3%). The tendency for early diagnosis (lower CA19-9 levels, smaller size, and earlier T stage), use of neoadjuvant chemotherapy, decreased morbidity, early recovery (lesser hospital stay and more minimally invasive surgery), and standardization of surgical techniques appeared to improve patient survival. Multivariable analysis for prognosis revealed that tumor biologic factors (increased preoperative serum CA19-9 level, tumor size, tumor differentiation, N stage, and presence of lymphovascular invasion), operational factors (status of the resection margin, type of operation, and year of operation), and genetic factors (K-ras mutations) correlated with patient survival. Conclusion: Early diagnosis and combined efforts, such as neoadjuvant chemotherapy and an established system of patient care, have gradually enhanced patient survival after operative resection for pancreatic ductal adenocarcinoma. Hence, multiplex prognostic parameters could provide additional information for improved prognostic estimation of pancreatic cancer exhibiting heterogeneous results.