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