Gefitinib in Treating Patients With Recurrent or Metastatic Esophageal or Gastroesophageal Junction Cancer

DISEASE CHARACTERISTICS: * Pathologically confirmed squamous cell carcinoma, adenocarcinoma, or large-cell undifferentiated carcinoma of the esophagus or gastroesophageal junction * Patients must have disease that is either metastatic (i.e., M1b by the definitions of the American Joint Committee on Cancer 1997 staging system) or recurrent after definitive therapy, and must be considered incurable by conventional treatments * Patients with small cell, or mixed small cell/non-small-cell histology are ineligible * Patients with lymphoma or sarcoma are also ineligible * Disease must be measurable in at least one dimension by physical exam, x-ray, CT scan or MRI, ultrasound, or endoscopy * Measurable disease can be a previously irradiated lesion if disease growth has been documented in the lesion since completion of radiation therapy * An elevation in carcinoembryonic antigen (CEA) is not sufficient to use by itself in response assessment PATIENT CHARACTERISTICS: * ECOG Performance Status 0-1 * WBC ≥ 3,000/mm\^3 * Platelet count ≥ 100,000/mm\^3 * Creatinine ≤ 2.0 mg/dL * Alkaline phosphatase and AST \< twice normal * Bilirubin \< twice normal * Calcium normal * No known severe hypersensitivity to study drug or any of its excipients * No clinical evidence of any other uncontrolled malignancy except adequately treated basal or squamous cell skin cancer or in situ cervical cancer * Pregnant or nursing women are ineligible * Fertile patients must use effective contraception * No evidence of severe or uncontrolled systemic disease (e.g., unstable or uncompensated respiratory, cardiac, hepatic, or renal disease) * No evidence of clinically active interstitial lung disease * Patients with chronic stable radiographic changes who are asymptomatic need not be excluded PRIOR CONCURRENT THERAPY: * Patients may not have received more than one previous systemic treatment regimen * Systemic treatment may have been given as part of definitive (adjuvant, neoadjuvant, concurrent, or sequential) management or for metastatic or recurrent disease * Previously untreated patients are also eligible * No previous treatment with study drug or any other epidermal growth factor receptor (EGFR) antagonists * More than 30 days since prior treatment with a non-approved or investigational drug * At least 4 weeks must have elapsed since any surgery, radiation therapy, or chemotherapy administration * Recovered from previous oncologic or other major surgery * No concurrent barbiturates (e.g., phenytoin), carbamazepine, rifampicin, phenobarbital or Hypericum perforatum (St. John's wort) * No concurrent surgery, radiation therapy, hormonal therapy, or other chemotherapy