Pancreatic cancer is the 14th most common cancer worldwide by incidence, but it is ranked in the 7th place of all cancer-related deaths, with an increased incidence trend in the recent years [1]. The 5-year survival rate is estimated to be 9 % in all stages, and it markedly decreases to 3 % in patients with advanced pancreatic cancer [2]. Pancreatic ductal adenocarcinoma (PDAC) is the most common malignant lesion, accounting for about 90 % of pancreatic cancers [3]. Surgical resection is the onl…