DX-8951f in Treating Patients With Metastatic Stomach Cancer

DISEASE CHARACTERISTICS: * Histologically confirmed gastric or gastroesophageal adenocarcinoma * Lymph node involvement and/or distant metastasis * No squamous cell carcinoma, small cell carcinoma, lymphoma, or leiomyosarcoma of the stomach * Measurable disease with indicator lesions outside the field of prior radiotherapy * At least 20 mm by conventional scan OR * At least 10 mm by spiral CT scan * Nonmeasurable lesions include the following: * Primary tumor * Bone lesions * Leptomeningeal disease * Ascites * Pleural/pericardial effusion * Inflammatory breast disease * Lymphangitis cutis/pulmonitis * Cystic lesions * Abdominal masses not confirmed and followed by imaging techniques * No prior treatment for locally advanced or metastatic disease * Prior adjuvant treatment allowed if disease recurrence noted at least 6 months after completion of adjuvant treatment * No known brain 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/mm3 * Platelet count at least 100,000/mm3 * Hemoglobin at least 9.0 g/dL Hepatic: * Bilirubin no greater than 2.0 mg/dL * AST or ALT no greater than 2.5 times upper limit of normal (ULN) (5 times ULN if liver metastases present) * Albumin at least 2.8 g/dL * PT or INR no greater than 1.5 times ULN (coumadin independent) Renal: * Creatinine no greater than 1.5 mg/dL Cardiovascular: * No active congestive heart failure * No uncontrolled angina * No myocardial infarction within the past 6 months Other: * No concurrent serious infection * No other malignancy within the past 5 years except nonmelanoma skin cancer or carcinoma in situ of the cervix * No overt psychosis, mental disability, or incompetence that would preclude informed consent * No other life-threatening illness * Not pregnant or nursing * Negative pregnancy test * Fertile patients must use effective contraception PRIOR CONCURRENT THERAPY: * See Disease Characteristics Biologic therapy: * No concurrent anti-cancer biologic therapy * No concurrent prophylactic colony stimulating factors during first course of therapy Chemotherapy: * Recovered from prior adjuvant chemotherapy * No other concurrent anti-cancer chemotherapy * No other concurrent anti-cancer cytotoxic therapy Endocrine therapy: * Concurrent megestrol for appetite stimulation allowed Radiotherapy: * At least 4 weeks since prior radiotherapy and recovered * No prior wide-field radiotherapy to more than 25% of bone marrow * No concurrent anti-cancer radiotherapy Surgery: * At least 4 weeks since prior major surgery and recovered * No concurrent anti-cancer surgery Other: * No other investigational drugs (including analgesics or antiemetics) for at least 4 weeks prior to, during, and for 4 weeks after study