Fenretinide in Treating Patients Who Have Undergone Surgery for Bladder Cancer

DISEASE CHARACTERISTICS: Histologically proven solitary or multifocal superficial (stage Ta, grades 1-2) transitional cell carcinoma (TCC) of the bladder meeting 1 of the following criteria: Newly diagnosed and no more than 4 weeks since resection Secondary after being tumor free (including carcinoma in situ) for more than 12 months with no intravesical therapy within that 12 months OR Histologically proven Ta, T1, or Tis TCC of the bladder previously treated with Bacillus Calmette-Guerin (BCG). Must have received 6 weeks of induction BCG followed by no evidence of disease by cystoscopy and cytology and then further treatment with 3 weekly doses of BCG. Visible tumor totally resected within 4 weeks prior to study entry and no further surgery, intravesical therapy, or systemic therapy planned No prostatic, prostatic urethral, or upper tract TCC involvement by the index tumor at resection No metastatic disease PATIENT CHARACTERISTICS: Age: 18 and over Performance status: Zubrod (Eastern Cooperative Oncology Group (ECOG)) 0-2 Life expectancy: At least 2 years Hematopoietic: white blood count (WBC) greater than 3,000/mm^3 Platelet count greater than 100,000/mm^3 Hemoglobin greater than 11.0 g/dL Hepatic: serum glutamic oxaloacetic transaminase (SGOT) or serum glutamic pyruvic transaminase (SGPT) less than 1.5 times upper limit of normal (ULN) Renal: Creatinine less than 2.0 mg/dL Other: Triglyceride level less than 2.5 times ULN No other concurrent malignancy except nonmelanomatous skin cancer No other malignancy within the past 5 years unless currently disease free, at least 6 months since prior therapy, no current or planned active therapy, and expected disease-free survival at least 2 years Not pregnant or nursing Negative pregnancy test Fertile patients must use effective contraception during and for 1 year after the study participation PRIOR CONCURRENT THERAPY: Biologic therapy: See Disease Characteristics No concurrent systemic biologic therapy Chemotherapy: See Disease Characteristics No prior systemic cytotoxic chemotherapy for bladder cancer At least 1 year since prior cytotoxic chemotherapy for nonbladder cancer No concurrent systemic chemotherapy Endocrine therapy: Not specified Radiotherapy: No prior radiotherapy to the bladder No concurrent radiotherapy Surgery: See Disease Characteristics Other: At least 3 months since prior high-dose vitamin A (greater than 25,000 IU) or beta carotene (at least 30 mg/day) At least 3 months since prior retinoid therapy