Oxaliplatin and Capecitabine in Treating Patients With Advanced Esophageal Cancer or Stomach Cancer

DISEASE CHARACTERISTICS: Histologically or cytologically confirmed adenocarcinoma of the esophagus, gastroesophageal junction, or gastric cardia for which no potentially curative or significant palliative therapy exists Unresectable disease Gastric cardia is defined as no more than 5 cm from the gastroesophageal junction into the stomach Measurable disease No known CNS metastases PATIENT CHARACTERISTICS: Age: 18 and over Performance status: ECOG 0-2 Life expectancy: At least 12 weeks Hematopoietic: Absolute neutrophil count at least 1,500/mm^3 Platelet count at least 100,000/mm^3 Hepatic: Bilirubin no greater than upper limit of normal (ULN) AST no greater than 3 times ULN Alkaline phosphatase no greater than 2 times ULN Renal: Creatinine no greater than 1.5 times ULN Creatinine clearance at least 60 mL/min Cardiovascular: No New York Heart Association class III or IV heart disease Other: Able to swallow capecitabine No unresolved gastrointestinal bleeding No uncontrolled infection No chronic debilitating disease No peripheral neuropathy grade 2 or greater No other malignancy within the past 5 years except adequately treated basal cell or squamous cell skin cancer or adequately treated noninvasive carcinoma Not pregnant or nursing Negative pregnancy test Fertile patients must use effective contraception PRIOR CONCURRENT THERAPY: Biologic therapy: No prior immunotherapy or biological therapy for recurrent or metastatic disease No concurrent biologic agents Chemotherapy: No prior chemotherapy for recurrent or metastatic disease Prior adjuvant or neoadjuvant chemotherapy (including combination chemotherapy and radiotherapy) allowed No other concurrent chemotherapy Endocrine therapy: Not specified Radiotherapy: See Chemotherapy No prior radiotherapy for recurrent or metastatic disease No prior radiotherapy to more than 25% of the bone marrow Prior adjuvant or neoadjuvant radiotherapy allowed More than 4 weeks since prior radiotherapy No concurrent radiotherapy Surgery: More than 4 weeks since prior abdominal exploration with surgical resection More than 3 weeks since prior abdominal exploration without surgical resection Other: No concurrent oral cryotherapy during oxaliplatin administration