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

DISEASE CHARACTERISTICS: * Histologically or cytologically confirmed adenocarcinoma of the esophagus or gastroesophageal junction * Metastatic disease * Unresectable disease with no curative options * Measurable disease with ≥ 1 lesion whose longest diameter can be accurately measured as ≥ 2.0 cm by conventional techniques or ≥ 1.0 cm by spiral CT * Not a candidate for a conventional multi-drug chemotherapy regimen with fairly standard dosing (i.e., patient is able to tolerate at least 80% of standard dosing) * Patients who have been offered and declined conventional multi-drug chemotherapy are eligible * No known CNS metastases PATIENT CHARACTERISTICS: * ECOG performance status (PS) 0-2 and age ≥ 65 years OR PS 2 and age ≥ 18 years but \< 65 years * Absolute neutrophil count ≥ 1,500/mm\^3 * Platelet count ≥ 100,000/mm\^3 * Total bilirubin normal * Alkaline phosphatase ≤ 2 times upper limit of normal (ULN) * Creatinine ≤ 1.5 times ULN * Creatinine clearance ≥ 60mL/min * AST and ALT ≤ 2.5 times ULN (≤ 5 times ULN in the presence of liver metastases) * Not pregnant or nursing * Negative pregnancy test * Fertile patients must use effective contraception * Willing to provide tissue samples for central review and research purposes * Able to swallow pills * No immunocompromised patients (other than related to the use of corticosteroids), including patients known to be HIV-positive * No co-morbid systemic illnesses or other severe concurrent disease that, in the judgment …