S0337, Gemcitabine After Surgery in Treating Patients With Newly Diagnosed or Recurrent Bladder Cancer

DISEASE CHARACTERISTICS: * Diagnosis of newly diagnosed or recurrent transitional cell bladder cancer meeting the following criteria: * Ta or T1 primary tumor * Grade 1 or 2 disease * No more than 2 recurrences (except for index tumor) within the 18 months prior to the index tumor's transurethral resection of the bladder tumor (TURBT) * Index tumor post-TURBT must meet the following criteria: * Ta or T1 tumor without any prior tumor in situ, grade 3 (high grade) disease within 2 years prior to index tumor TURBT, or invasion of the muscularis propria (stage ≥ T2) * Grade 1 or 2 disease (similar to papillary urothelial neoplasm of low malignant potential and low-grade bladder cancer) * Not a candidate for a therapy other than TURBT (e.g., a series of instillations of intravesical immunotherapy \[e.g., BCG\] or intravesical chemotherapy, or cystectomy or partial cystectomy) * Negative upper tract imaging studies within 1 year (365 days) prior to study entry * Imaging studies may be performed after registration provided it is done prior to TURBT on the day of treatment * No urothelial cancer of the prostate or more distal urethra (or urethra at all in women) as assessed by endoscopy * Must have a negative urine culture (less than or equal to 10,000 col/mL, mixed flora-likely contamination) OR negative urine analysis for infection AND negative nitrates on reagent strip, ≤ 10 white blood cell count (WBC)/high-power field, and no rods or organisms on examination…