Clinical Complete Response after Neoadjuvant Chemotherapy for Muscle-invasive Bladder Cancer: A Call for Standardized Assessments and Definitions

The ability to accurately determine a complete clinical response (cCR) to neoadjuvant chemotherapy (NAC) before cystectomy could have paradigm-shifting implications for the management of muscle-invasive bladder cancer. Level 1 evidence demonstrates that up to 40% of patients are downstaged to pT0 disease following NAC, presenting an intriguing opportunity to identify select patients who might be spared the morbidity of radical surgery. However, clinical investigations in this space are hindered by lack of a uniform approach to postchemotherapy restaging and a standardized definition of cCR. In this mini-review, we discuss the current limitations to restaging of muscle-invasive bladder cancer following neoadjuvant chemotherapy and their implications for personalized medicine and translational research. We conclude that there is an unmet need to optimize and standardize restaging evaluation and definitions of a complete clinical response. There is no standardized approach to restaging after neoadjuvant chemotherapy or consensus definition of a clinical complete response, limiting our ability to advance precision medicine and bladder preservation strategies in muscle-invasive bladder cancer.