Predicting Effective Therapy in Pancreatic Cancer

Inclusion Criteria: * Histological or cytological diagnosis of pancreatic adenocarcinoma, confirmed at MSKCC, AJCC stage IV disease at time of enrollment. * Patient planning to receive treatment with FOLFIRINOX or gem/nab-P chemotherapy, with or without investigational agents. * Prior surgery, chemotherapy and/or radiation therapy for AJCC Stage I-III pancreatic adenocarcinoma is permitted. * ECOG performance status 0-2. * A minimum age of 18 years old. Exclusion Criteria: * Prior chemotherapy for AJCC stage IV pancreatic adenocarcinoma * Known to be HIV positive on antiretroviral therapy * Prior organ allograft * Any medical or psychiatric condition that may interfere with the ability to comply with protocol procedures