Neoadjuvant chemotherapy for 3 months with the intensified MVAC (6 cycles administered every 2 weeks): METHOREXATE: 30 mg/m2 D1 - VINBLASTINE: 3 mg/m2 D2 - ADRIAMYCINE 30 mg/m2 D2 - CISPLATINE 70 mg/m2 D2. + G-CSF: 5 µg/kg from D4 to D10 New maximal standardized TURB at the end of the chemotherapy. In case of a lesion localized at the bladder dome, and if a maximal TURB appears to be unsafe, a partial cystectomy without lymph node dissection will be performed.