RATIONALE: Drugs used in chemotherapy use different ways to stop tumor cells from dividing so they stop growing or die. It is not yet known if eflornithine is more effective than no further therapy in treating bladder cancer.

PURPOSE: Randomized phase III trial to determine the effectiveness of eflornithine in treating patients who have newly diagnosed or recurrent bladder cancer.

OBJECTIVES: I. Determine whether treatment with eflornithine is effective in preventing recurrence of tumor after transurethral resection in patients with low grade, superficial transitional cell carcinoma of the bladder. II. Determine the incidence and severity of toxicities associated with the long-term use of this drug in this patient population.

OUTLINE: This is a randomized, double blind, multicenter study. Patients are stratified according to disease status (newly diagnosed vs recurrent), clinical stage (Ta vs T1), grade (G1 vs G2), and focus (multifocal vs unifocal). Patients receive either oral eflornithine or placebo once daily. Treatment continues for 1 year in the absence of disease progression or unacceptable toxicity. Patients are followed every 3 months during the first 2 years, every 6 months for the third year, and then annually for the fourth year.

PROJECTED ACCRUAL: A total of 450 patients (225 per arm) will be accrued to this study within 1.5 years.

DISEASE CHARACTERISTICS: Histologically confirmed low grade (grade 1 or 2), superficial (stage Ta or T1) transitional cell carcinoma (TCC) of the bladder Newly diagnosed or recurrent All visible tumor must have been resected within the past 12 weeks Standard clinical management determined to be expectant observation without further surgery, intravesical therapy, or systemic therapy No prior upper tract TCC No history of grade 3 TCC, carcinoma in situ including severe dysplasia, non-TCC histology, or TCC greater than or equal to T2 No involvement of upper urinary tract prior to or at the time of initial tumor resection Abdominal CT scan, IVP, or retrograde pyelogram within the past 3 months to rule out upper urinary tract tumor

PATIENT CHARACTERISTICS: Age: 18 and over Performance status: Not specified Life expectancy: Not specified Hematopoietic: Not specified Hepatic: Not specified Renal: Not specified Other: Not pregnant or nursing Negative pregnancy test Fertile patients must use effective contraception No prior malignancy within the past 5 years and no concurrent malignancy except nonmelanomatous skin cancer or carcinoma in situ of the cervix No clinically significant hearing loss (i.e., hearing loss effects everyday life and/or wears a hearing aide) No other significant medical or psychiatric condition

PRIOR CONCURRENT THERAPY: Biologic therapy: At least 4 weeks since prior growth factors No concurrent growth factors Chemotherapy: No prior systemic chemotherapy for bladder cancer No concurrent intravesical therapy At least 4 weeks since prior chemotherapy No concurrent chemotherapy Endocrine therapy: At least 4 weeks since prior high dose steroids or prednisone No concurrent high dose steroids No concurrent prednisone or its equivalent in excess of 10 mg/day Radiotherapy: No prior radiotherapy for bladder cancer At least 4 weeks since prior radiotherapy No concurrent radiotherapy Surgery: See Disease Characteristics Other: At least 4 weeks since prior carbamazepine or experimental drugs No concurrent carbamazepine or experimental drugs