Irinotecan in Treating Asian Patients With Solid Tumors

DISEASE CHARACTERISTICS: * Histologically or cytologically confirmed solid tumors * Failed at least one line of prior chemotherapy * Must belong to either Chinese, Malay, or Indian ethnic groups * Previously irradiated disease allowed provided marker lesions not within the irradiated field * Presence of at least one bidimensionally measurable, non-CNS indicator lesion, defined by radiologic study (including CT or MRI scan, ultrasound, or chest X-ray) or physical exam, meeting 1 of the following criteria: * Measurable disease on CT or MRI scan must have one diameter ≥ 1 cm and one diameter ≥ 2 cm * Measurable disease on chest X-ray or ultrasound must have both diameters ≥ 2 cm * Palpable tumor masses that cannot be evaluated radiologically must have two diameters ≥ 2 cm * Measurable skin lesion must have at least one diameter ≥ 1 cm * No unidimensionally measurable or evaluable only disease * No known brain or leptomeningeal metastasis * No uncontrolled large pleural effusions PATIENT CHARACTERISTICS: * ECOG performance status 0-2 * Life expectancy ≥ 3 months * Absolute granulocyte count ≥ 1,000/µL * WBC ≥ 3,500/µL * Hemoglobin ≥ 9 g/dL * Platelet count ≥ 100,000/µL * Serum total bilirubin ≤ 2.0 mg/dL * ALT/AST \< 2.5 times normal (5 times normal in patients with known metastatic disease in the liver) * Creatinine clearance ≥ 60 mL/min * Not pregnant or nursing * Negative pregnancy test * Fertile patients must use effective contraception * No medical problems severe enough to prevent compliance with the study requirements * No prior malignancies, except for adequately treated basal cell or squamous cell carcinoma, carcinoma in situ of the cervix, or other cancer for which the patient has been disease-free for 5 years * No active or uncontrolled infection * No pre-existing cardiac disease, including congestive heart failure, arrhythmia requiring treatment, or myocardial infarction within the past 3 months * No pneumonitis * No uncontrolled diabetes mellitus (i.e., random blood glucose \> 200 mg/dL) * No inflammatory bowel disease PRIOR CONCURRENT THERAPY: * At least 1 week since prior and no concurrent ketoconazole * More than 4 weeks since prior chemotherapy or radiotherapy * At least 2 weeks since prior and no concurrent Hypericum perforatum (St. John wort) * No prior irinotecan hydrochloride * No concurrent investigational antineoplastic therapy or other investigational drugs