DISEASE CHARACTERISTICS: Histologically confirmed epithelial carcinoma of the ovary, fallopian tube, or peritoneum At least 3 prior courses of standard platinum-paclitaxel regimen Patients with taxane allergy may enter this study after 3 courses of platinum based treatment CA125 at least 35 measured within 30 days of commencement of treatment Measurable disease not required No CNS metastases, carcinomatous meningitis or interstitial pulmonary fibrosis

PATIENT CHARACTERISTICS: Age: 18 and over Performance status: Karnofsky 60-100% Life expectancy: Not specified Hematopoietic: Neutrophil count at least 1,500/mm3 Platelet count at least 100,000/mm3 Hepatic: Bilirubin no greater than 1.5 mg/dL Renal: Creatinine no greater than 1.5 mg/dL Calcium less than 12.0 mg/dL Cardiovascular: No unstable angina No New York Heart Association grade III or IV cardiac disease Pulmonary: See Disease Characteristics Other: No active or uncontrolled infection No history of seizures No known Gilbert's Disease No medical or psychiatric conditions that makes patient a poor risk for participation in this study Not pregnant or lactating Negative pregnancy test

PRIOR CONCURRENT THERAPY: Biologic therapy: No prior immunotherapy Chemotherapy: No prior irinotecan or topotecan Endocrine therapy: Not specified Radiotherapy: No prior radiotherapy to the pelvis Surgery: At least 4 weeks since prior surgery and recovered Other: No concurrent phenytoin, phenobarbital, or other antiepileptic prophylaxis