Gemcitabine Plus Cisplatin in Treating Patients With Ovarian Epithelial Cancer or Primary Peritoneal Cancer That Is Recurrent or Has Not Responded to Platinum-based Chemotherapy

DISEASE CHARACTERISTICS: * Histologically confirmed primary ovarian epithelial cancer or primary peritoneal carcinoma * Recurrent or persistent disease * Bidimensionally measurable disease by physical examination or medical imaging techniques * Sonography is acceptable if lesions are clearly defined on initial examination and bidimensionally measurable * Ascites and pleural effusions are not considered measurable disease * Must not be eligible for a higher priority Gynecologic Oncology Group protocol * Must have received one, and only one, prior platinum-based chemotherapy regimen containing carboplatin, cisplatin, or another organoplatinum compound for management of primary disease * Initial treatment may include high-dose therapy, consolidation, or extended therapy administered after surgical or nonsurgical assessment * If no prior paclitaxel, a second regimen containing paclitaxel allowed * Platinum-resistant or refractory (i.e., treatment-free interval after platinum-based therapy of less than 6 months or progressed during platinum-based therapy) PATIENT CHARACTERISTICS: Age: * Not specified Performance status: * GOG 0-2 Life expectancy: * Not specified Hematopoietic: * Absolute neutrophil count at least 1,500/mm\^3 * Platelet count at least 100,000/mm\^3 Hepatic: * Bilirubin no greater than 1.5 times upper limit of normal (ULN) * SGOT no greater than 2.5 times ULN * Alkaline phosphatase no greater than 2.5 times ULN Renal: * Creatinine no greater than 1.5 times ULN Other: * Not pregnant * Negative pregnancy test * Fertile patients must use effective contraception * No active infection requiring antibiotics * No other malignancy within the past 5 years except nonmelanoma skin cancer * Sensory and motor neuropathy no greater than grade 1 PRIOR CONCURRENT THERAPY: Biologic therapy: * At least 3 weeks since prior biologic or immunologic therapy for ovarian or peritoneal cancer Chemotherapy: * See Disease Characteristics * No other prior cytotoxic chemotherapy for recurrent or persistent disease, including retreatment with initial chemotherapy regimens * No prior gemcitabine * At least 3 weeks since prior chemotherapy for ovarian or peritoneal cancer and recovered Endocrine therapy: * At least 1 week since prior hormonal therapy for ovarian or peritoneal cancer * Concurrent continuation of hormonal replacement therapy allowed Radiotherapy: * At least 3 weeks since prior radiotherapy for ovarian or peritoneal cancer and recovered * No prior radiotherapy to only site of measurable disease * No prior radiotherapy to more than 25% of bone marrow Surgery: * See Disease Characteristics * At least 3 weeks since prior surgery for ovarian or peritoneal cancer and recovered Other: * At least 3 weeks since other prior therapy for ovarian or peritoneal cancer * No prior cancer treatment that would preclude study