Gemcitabine plus nub-paclitaxel (GEMABR) regimen was recently presented at an international oncology meeting and represents a new standard regimen in the treatment of metastatic pancreatic cancer. Therefore, it was decided to consider the balance of safety and efficacy as a preoperative chemotherapy, the investigators use the NAC-GEMABR regimen includes only two cycles (three times weekly and one week rest) of GEMABR regimen.