Study of Erlotinib and Chemotherapy for Unresectable or Metastatic Cancer of the Esophagus and Gastric Cardia

In this study, Erlotinib and 5-Fluorouracil (5-FU), Leucovorin and Oxaliplatin (a regimen known also as FOLFOX-6) will be the chemotherapy study drugs. The main purpose of this study is to test the safety and effectiveness of this combination of chemotherapy drugs and to see how they affect your cancer. Another purpose of this study is to examine samples from your blood and tumor. This research will be done to better understand how subjects respond to treatment. Specifically, researchers will look at the way your genes and proteins respond to drugs like those used in this study.