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