Personalized Peptide Vaccine in Treating Patients With Advanced Pancreatic Cancer or Colorectal Cancer

This phase I trial studies the side effects and best way to give personalized peptide vaccine in patients with pancreatic or colorectal cancer that has spread to other places in the body and usually cannot be cured or controlled with treatment (advanced). Personalized peptide vaccine is a vaccine developed from patient’s own tumor cells and blood in order to use as a biological therapy. Biological therapies, such as personalized peptide vaccine may attack tumor cells and stop them from growing or kill them.