Effectiveness of an Immediate Postoperative Intravesical Instillation With Either Gemcitabine or Epirubicin in Patients With Urinary Bladder Cancer (Gemcitabine Epirubicin Normal SAline)

This study is comparing two chemotherapy drugs — gemcitabine and epirubicin — when instilled directly into the bladder immediately after surgery to remove bladder tumors. The goal is to see which drug is more effective at preventing bladder cancer from coming back. **You may be eligible if...** - You have a primary or recurrent (returning) bladder tumor being removed by transurethral resection (a common bladder cancer procedure) - Your blood counts, kidney, and liver levels are within acceptable ranges - You are in generally good health (ECOG performance status 0 or 1) - You have had a urine culture showing no infection - A recent CT scan showed no upper urinary tract tumor **You may NOT be eligible if...** - You have had more than 2 low-grade bladder tumors in the past 18 months - You have had a high-grade bladder tumor in the past 9 months - Your bladder tumor has invaded the muscle layer (muscle-invasive disease) - You have had prior bladder chemotherapy instillations or BCG treatment in the last 6 months - You have cancer in the urethra or upper urinary tract - You have had pelvic radiation or another cancer in the past 5 years - Your tumor resection was incomplete or missing muscle tissue in the sample Talk to your doctor to see if this trial is right for you.