Capecitabine With or Without Sunitinib Malate as First-Line Therapy in Treating Patients With Metastatic Cancer of the Esophagus or Gastroesophageal Junction

RATIONALE: Drugs used in chemotherapy, such as capecitabine, work in different ways to stop the growth of tumor cells, either by killing the cells or by stopping them from dividing. Sunitinib malate may stop the growth of tumor cells by blocking some of the enzymes needed for cell growth and by blocking blood flow to the tumor. It is not yet known whether capecitabine is more effective when given alone or together with sunitinib malate in treating patients with metastatic esophageal cancer or gastroesophageal junction cancer. PURPOSE: This randomized phase II trial is studying how well capecitabine works compared with capecitabine given together with sunitinib malate as first-line therapy in treating patients with metastatic cancer of the esophagus or gastroesophageal junction.