Genistein, Gemcitabine, and Erlotinib in Treating Patients With Locally Advanced or Metastatic Pancreatic Cancer

RATIONALE: Drugs used in chemotherapy, such as gemcitabine, work in different ways to stop the growth of tumor cells, either by killing the cells or by stopping them from dividing. Erlotinib may stop the growth of tumor cells by blocking some of the enzymes needed for cell growth. Genistein may help gemcitabine and erlotinib kill more tumor cells by making tumor cells more sensitive to the drugs. PURPOSE: This phase II trial is studying how well giving genistein together with gemcitabine and erlotinib works in treating patients with locally advanced or metastatic pancreatic cancer.