Adjuvant radiotherapy for pathological high-risk muscle invasive bladder cancer: time to reconsider?

Radical cystectomy with extended pelvic lymph-node dissection, associated with neo-adjuvant chemotherapy, remains the standard of care for advanced, non-metastatic muscle-invasive bladder cancer (MIBC). Loco-regional control is a key factor in the outcome of patients since it is related to overall survival (OS), disease-free survival (DFS) and cause-specific survival. The risk of loco-regional recurrence (LRR) is correlated to pathological factors as well as the extent of the lymphadenectomy. In addition, neither pre- nor post-operative chemotherapy have shown a clear impact on LRR-free survival. Several recent publications have led to the development of a nomogram predicting the risk of LRR, in order to identify patients most likely to benefit from adjuvant radiotherapy. Given the high risk of LRR for selected patients and improvements in radiation techniques that can reduce toxicity, there is a growing interest in adjuvant radiotherapy; international cooperative groups have come together to provide the rationale in favor of adjuvant radiotherapy. Clinical trials in order to reduce the risk of pelvic relapse are opened based on this optimizing patient selection. The aim of this critical literature review is to provide an overview of the rationale supporting the studies of adjuvant radiation for patients with pathologic high-risk MIBC.