GENSAA Prospective Phase III Randomized Clinical Trial Comparing the Effectiveness of Immediate Postoperative Intravesical Instillation With Either Gemcitabine Hydrochloride or Epirubicin Hydrochloride in Patients With Urinary Bladder Cancer (Gemcitabine Epirubicin Normal SAline)

Bladder cancer (BLCa) is the seventh most commonly diagnosed cancer in the male population worldwide, while it drops to tenth when both genders are considered. At diagnosis about 75% of the patients suffer from non-muscle-invasive BLCa. The natural history of this disease is characterised by recurrence and progression. In order to reduce the possibilities for recurrence, and therefore progression, an immediate single intravesical instillation (ISIVI) of a chemotherapeutic agent has been shown to act by destroying circulating tumour cells after transurethral resection of urinary bladder tumors (TURB), and by an ablative effect on residual tumour cells at the resection site and on small overlooked tumours. Several agents, among them gemcitabine and epirubicin, have been used for the ISIVI so far. Moreover, four large meta-analyses comprising 1,476 to 3,103 patients have consistently shown that after TURB, ISIVI significantly reduces the recurrence rate compared to TURB alone. Furthermore, two meta-analyses suggest efficacy of continuous saline irrigation (CSI) in the prevention of early recurrences. The prevention of tumour cell implantation should be initiated within the first few hours after TURB. After that, tumour cells are firmly implanted and are covered by the extracellular matrix. In all ISIVI studies, the instillation was administered within 24 hours. Until today, no randomised comparisons of individual drugs, combined or not with CSI, have been conducted. After the initial TURB, the patients will be treated with CSI for 24 hours. Then, they will be randomised, either to gemcitabine or epirubicin, and within 6 hours after the TURB they will receive an ISIVI with gemcitabine or epirubicin, as follows: \- GROUP A: Gemcitabine hydrochloride 2gr in 100ml 0.9% NaCl for 45-60 minutes \- GROUP B: Epirubicin hydrochloride 50mg in 50ml 0.9% NaCl for 45-60 minutes During the ISIVI the CSI will be stopped. The ISIVI will not be applied in the following cases: * Active bleeding, which does not allow to interrupt the CSI * Postoperative fever > 38°C * Deep resection of the tumor, which could be associated with bladder perforation and therefore potential extravasation of the administered drug * Known allergy to gemcitabine or epirubicin The postoperative follow-up for patients with disease stage pTis, Ta, T1 low grade (LG) / high grade (HG), will be done according to the Guidelines of the European Association of Urology (EAU) for non-muscle-invasive bladder cancer, as follows: * 1st and 2nd year: Cystoscopy \& cytological examination of urine every 3 months, CT Urography every 12 months for HG patients * 3rd year: Cystoscopy \& cytological examination of urine every 6 months, CT Urography every 12 months for HG patients