Advanced pancreatic ductal adenocarcinoma (PDAC) is an aggressive and chemo-resistant disease with extremely low 5-year survival rate. Gemcitabine has been the cornerstone of metastatic PDAC treatment for more than a decade , although survival benefit was very poor. Nab-paclitaxel added to gemcitabine has showed improving survival and overall response rate vs gemcitabine alone in metastatic PDAC first-line treatment in the MPACT phaseIII study, which represents one of the standards of care in advanced PDAC therapy. S-1 is an oral 5-fluorouracil (5-FU) prodrug, and shown to be non-inferior to gemcitabine on OS for unresectable pancreatic cancer. Meanwhile, adjuvant chemotherapy with S-1 monotherapy was found to significant prolong survival of pancreatic cancer patients when compared with gemcitabine. This study is to explore the efficacy and safety of nab-paclitaxel plus S-1(AS) and nab-paclitaxel plus gemcitabine(AG) as first-line treatment in advanced pancreatic ductal adenocarcinoma (PDA) with primary tumor nonexcision in Chinese patients.
