Appraisal of 5-year recurrence-free survival after surgery in pancreatic ductal adenocarcinoma

Background/Purpose: Pancreatic ductal adenocarcinoma (PDAC) is regarded as incurable, with a limited survival rate after curative resection. The aim of this study was to explore long-term survival and late recurrence of PDAC after surgery. Methods: Medical data of 859 patients who underwent resection between 1995 and 2014 were retrospectively examined. The clinicopathological features of the 5-year recurrence-free survivors and the patients with recurrent disease after 5 years were investigated separately. Results: Among the 768 patients who were finally included in this study, elevated CA 19-9, tumor size, poor differentiation, and positive lymph node metastasis were associated with recurrence. In 89 patients with 5-year RFS, age, tumor size, differentiation, and lymph node metastasis were statistically significant predictive factors. Among these patients, disease relapse occurred in 11 patients; age was the only difference compared to those who remained free of recurrence. Conclusions: Most prognosticators failed to predict the risk of recurrence in the 5 years following surgery for PDAC, and recurrence can occur even at time points up to 100 months. Therefore, cure of PDAC cannot be guaranteed by a 5-year recurrence-free interval, and further studies into the inherent nature of PDAC are needed to develop adequate surveillance systems which may lead to improvements in survival.