Combination Chemotherapy Consisting of Gemcitabine And Topotecan in Treating Patients With Refractory or Recurrent Ovarian or Fallopian Tube Cancer

DISEASE CHARACTERISTICS: * Histologically documented refractory or recurrent ovarian epithelial or fallopian tube cancer * No borderline ovarian cancer * Extra-ovarian papillary serous tumors eligible * Must not be eligible for any higher priority phase II or III GOG protocol PATIENT CHARACTERISTICS: Age: * 18 and over Performance status: * GOG 0-2 Life expectancy: * Not specified Hematopoietic: * Granulocyte count at least 1,500/mm\^3 * Platelet count at least 100,000/mm\^3 Hepatic: * SGOT no greater than 3 times upper limit of normal (ULN) * Bilirubin no greater than 1.5 mg/dL * Elevated levels of alkaline phosphatase allowed Renal: * Creatinine no greater than 1.5 mg/dL Cardiovascular: * No angina pectoris or clinically significant multifocal uncontrolled cardiac dysrhythmias * No uncontrolled hypertension Other: * No other active malignancy * No prior malignancy within the past 5 years except nonmelanomatous skin cancer * No active infection * No underlying medical problem that would prevent compliance * No known hypersensitivity to E. coli-derived drug preparations * Fertile patients must use effective contraception PRIOR CONCURRENT THERAPY: Biologic therapy: * Not specified Chemotherapy: * Must have received at least 1 prior platinum- and paclitaxel-based regimen * At least 4 weeks since prior chemotherapy * No prior topotecan and/or gemcitabine * No prior chemotherapy for a different prior malignancy Endocrine therapy: * Not specified Radiotherapy: * No prior radiotherapy to more than 10% of bone marrow * At least 2 weeks since limited field radiation therapy Surgery: * Not specified