Sorafenib. ICORG 06-41, V4

DISEASE CHARACTERISTICS: * Histologically confirmed esophageal and/or gastric adenocarcinoma * Relapsed or progressed disease after prior platinum-based chemotherapy and not a suitable candidate for radical therapy * At least 1 unidimensionally measurable lesion as assessed by RECIST criteria * No uncontrolled, symptomatic brain metastases * Patients with intracranial bleeding into metastases allowed provided the disease is well-controlled and not undergoing acute steroid therapy or taper (chronic steroid therapy allowed provided the dose is stable for 1 month prior to and following screening radiographic studies) PATIENT CHARACTERISTICS: * ECOG performance status 0-2 * Life expectancy ≥ 2 months * Hemoglobin ≥ 9.0 g/dL * Absolute neutrophil count ≥ 1.5 x 10\^9/L * Platelet count ≥ 100 x 10\^9/L * Total bilirubin ≤ 1.5 times upper limit of normal (ULN) * ALT/AST ≤ 2.5 times ULN (≤ 5 times ULN for patients with liver involvement) * Alkaline phosphatase ≤ 2.5 times ULN (≤ 4 times ULN for patients with bony involvement) * INR ≤ 1.5 * aPTT normal * Creatinine ≤ 1.5 times ULN * Not pregnant or nursing * Negative pregnancy test * Fertile patients must use effective barrier method contraception prior to and during study therapy (men and women) and for 3 months after completion of study therapy (men) * Not planning pregnancy within 6 months after completion of study therapy * No history of cardiac disease, including any of the following: * NYHA class III-IV congestive heart failure * Active coronary artery disease (myocardial infarction more than 6 months prior to study entry allowed) * Cardiac arrhythmias requiring anti-arrhythmic therapy (beta blockers or digoxin are permitted) * No uncontrolled hypertension (systolic BP \> 150 mm Hg or diastolic BP \> 90 mm Hg, despite optimal medical management) * No known HIV infection or chronic hepatitis B or C * No active, clinically serious infections \> CTCAE grade 2 * No thrombotic or embolic events (e.g., cerebrovascular accident including transient ischemic attacks within the past 6 months) * No pulmonary hemorrhage or bleeding event \> CTCAE grade 2 within the past 4 weeks * No other hemorrhage or bleeding event \> CTCAE grade 3 within the past 4 weeks * No serious, nonhealing wound, ulcer (apart from the tumor), or bone fracture * No evidence or history of bleeding diathesis or coagulopathy * No current signs or symptoms of severe progressive or uncontrolled hepatic, hematological, renal, endocrine, pulmonary, or cardiac disease * No known or suspected allergy to sorafenib or any agent given in the course of this trial * No previous cancer that is distinct in primary site or histology from esophago-gastric junction cancer except for carcinoma in situ of the cervix, treated basal cell carcinoma, superficial bladder tumors \[Ta and Tis\], or any cancer curatively treated \> 3 years prior to study entry * No concurrent cancer that is distinct in primary site or histology from esophago-gastric cancer * No substance abuse, medical, psychological, or social conditions that may interfere with the patient's participation in the study or evaluation of the study results * No condition that impairs the patient's ability to swallow whole pills * No malabsorption condition * No seizure disorder requiring medication (e.g., steroids or antiepileptics) * No familial, sociological, or geographical condition potentially hampering compliance with the study protocol and follow-up schedule * No significant traumatic injury within the past 4 weeks PRIOR CONCURRENT THERAPY: * See Disease Characteristics * At least 3 weeks since prior local radiotherapy * At least 3 weeks since prior biologic response modifiers (e.g., G-CSF) * G-CSF and other hematopoietic growth factors allowed in the management of acute toxicity (e.g., febrile neutropenia) when clinically indicated or at the discretion of the investigator, however they may not be substituted for a required dose reduction * Concurrent chronic erythropoietin allowed provided no dose adjustment is undertaken within 2 months prior to the study or during the study * At least 4 weeks since prior major surgery or open biopsy * At least 4 weeks since prior and no concurrent radiotherapy * Prior or concurrent palliative radiotherapy to symptomatic disease sites allowed (unless the site to be irradiated is one of the target lesions used for response assessment) * At least 4 weeks since prior and no concurrent anticancer chemotherapy, immunotherapy, or hormonal therapy (except bisphosphonates) * At least 30 days since prior and no concurrent investigational drug therapy * At least 5 weeks since prior and no concurrent mitomycin C or nitrosoureas * At least 4 months since prior autologous bone marrow transplant or stem cell rescue * No history of organ allograft * No prior licensed or investigational tyrosine kinase inhibitor or antiangiogenic agent (e.g., sunitinib or bevacizumab) * No prior sorafenib tosylate * No prior licensed or investigational drug treatment that targets the RAS, VEGF, VEGFR, or EGFR pathway * No concurrent rifampin or St. John wort * No concurrent therapeutic anticoagulation with vitamin K antagonists (e.g., warfarin, heparins, or heparinoids) * Low-dose warfarin (1 mg by mouth once a day) allowed provided INR is \< 1.5 * Low-dose aspirin allowed * No concurrent renal dialysis