Selumetinib Active Not Recruiting Phase 2 Trials for Stage IIB Pancreatic Cancer AJCC v6 and v7 / Stage IIB Pancreatic Cancer / Stage II Pancreatic Cancer / Stage III Pancreatic Cancer AJCC v6 and v7 / Stage III Pancreatic Cancer / Stage IIA Pancreatic Cancer / Stage IV Pancreatic Cancer AJCC v6 and v7 / KRAS NP_004976.2:p.G12R / Stage IV Pancreatic Cancer / Stage IIA Pancreatic Cancer AJCC v6 and v7 / Stage II Pancreatic Cancer AJCC v6 and v7 Treatment