Adjuvant Radiotherapy in Patients With Pathological High-risk Bladder Cancer (GETUG-AFU 30)

Inclusion Criteria: To be eligible, the patients must fulfil all of the following inclusion criteria: 1. Patients with histologically-confirmed muscle-invasive bladder cancer, either with pure urothelial carcinomas, or dominant urothelial carcinomas (\>50%) combined with other histological variants including: micropapillary, epidermoid, or adenocarcinomas, are eligible. Patients with small cell variants, pure adenocarcinomas, or pure epidermoid carcinomas are not eligible. 2. Patients with radical cystectomy and pelvic lymph nodes dissection with no microscopic residual disease (R0 and R1). Note that only R1 patients without urinary diversion as orthotropic neo-bladder replacement are eligible for the study, to limit cystectomy bed radiation induced toxicities. 3. Patients with tumours of TNM staging: pN0-2, M0 by imagery, and pT3a, pT3b, pT4a, and pT4b, as well as, pTX-pN1-2, pTX-NX-R1 are eligible. 4. Patients having received neo-adjuvant or adjuvant chemotherapy treatment are eligible. Randomization is allowed only if AE due to chemotherapy are ≤grade 2 at randomization. 5. Patients ≥18 years old. 6. Eastern Cooperative Oncology Group (ECOG) performance status ≤2. 7. Absolute neutrophil count (ANC) ≥1500 cells/mm³. 8. Platelets ≥100000 cells/mm³. 9. Haemoglobin ≥8 g/dL (Note: following a blood transfusion or another intervention if required). 10. Adequate hepatic function: aspartate aminotransferase (ASAT) and alanine aminotransferase (ALAT) ≤2.5 x upper limit of normal (ULN); or ≤3.5 x ULN in the case of concurrent disease with known etiology and for which a corrective treatment is possible. 11. Adequate renal function: clearance \>30 mL/min (MDRD). 12. Patients having provided written informed consent prior to any study-related procedures. 13. Patients affiliated to the social security scheme. 14. Patients willing and able to comply with the scheduled visits, treatment plan, laboratory tests, and other study procedures indicated in the protocol. Exclusion Criteria: Patient must not be enrolled if he/she fulfils any of the following non-inclusion criteria: 1. Patients with R1 resection and with orthotropic neo-bladder reconstruction as urinary diversion are not eligible. 2. Patients with clinical or radiological evidence of metastases or N3 staged bladder cancer are not eligible. 3. Prior invasive solid tumours or haematological malignancies unless disease free for a minimum of 3 years prior to randomisation except: * skin basal cell carcinoma, * in situ epithelioma of the cervix, * or prostate cancer: incidentally discovered during cystoprostatectomy and pelvic lymph node dissection and with a good prognosis (T stage \<pT3b and/or Gleason \<8 and pN- and/or post-operative prostate-specific antigen (PSA) \<0.1 nanogram/mL), 4. Prior pelvic radiotherapy. 5. Patients with active inflammatory bowel disease. 6. Patients who required surgical treatment for bowel obstruction before bladder cancer diagnosis or after cystectomy. 7. Prior chemotherapy for other malignant diseases within the previous 5 years, except for neoadjuvant pre-cystectomy chemotherapy or adjuvant chemotherapy which are permitted. 8. Patients with the following severe acute co-morbidity are not eligible: * Unstable angina or congestive heart failure that required hospitalization in the 6 months before randomisation. * Transmural myocardial infarction in the 6 months prior to randomisation. * Acute bacterial or fungal infection requiring intravenous antibiotics at randomisation. * Chronic obstructive pulmonary disease exacerbation or other respiratory illness requiring hospitalization or precluding study therapy at the time of randomisation. * Severe hepatic disease: Child-Pugh Class B or C hepatic disease. * Known acquired immune deficiency syndrome (AIDS); the study treatment could impact blood count. 9. Patients with any other disease or illness which requires hospitalization or is incompatible with the study treatment are not eligible. 10. Patients unable to comply with study obligations for geographic, social, or physical reasons, or who are unable to understand the purpose and procedures of the study. 11. Patients enrolled in another therapeutic study within 30 days prior of randomisation. 12. Person deprived of their liberty or under protective custody or guardianship.