DISEASE CHARACTERISTICS: Histologically confirmed persistent, recurrent, or refractory endometrial carcinoma who have failed prior first line chemotherapy Bidimensionally measurable disease by physical exam or medical imaging techniques (sonography acceptable if lesion(s) are clearly defined and measurable in two dimensions) Ascites and pleural effusions are not measurable

PATIENT CHARACTERISTICS: Age: Not specified Performance status: GOG 0-2 Life expectancy: At least 2 months Hematopoietic: WBC at least 3,000/mm3 Platelet count at least 100,000/mm3 Granulocyte count at least 1,500/mm3 Hemoglobin at least 8 g/dL Hepatic: Bilirubin no greater than 1.5 times upper limit of normal (ULN) SGOT no greater than 3 times ULN Alkaline phosphatase no greater than 3 times ULN Renal: Creatinine no greater than 2.0 mg/dL Other: Not pregnant or nursing Negative pregnancy test Fertile patients must use effective contraception No significant infection

PRIOR CONCURRENT THERAPY: Biologic therapy: Not specified Chemotherapy: See Disease Characteristics At least 4 weeks since prior chemotherapy and recovered Endocrine therapy: Not specified Radiotherapy: At least 4 weeks since prior radiotherapy and recovered Surgery: At least 4 weeks since prior surgery and recovered Other: At least 4 weeks since any prior therapy directed at malignant endometrial tumor(s) At least 4 weeks since prior folate-containing vitamins No concurrent folate-containing vitamins No other concurrent anticancer therapy