Approaches to Clinical Complete Response after Neoadjuvant Chemotherapy in Muscle-Invasive Bladder Cancer: Possibilities and Limitations

SIMPLE SUMMARY: Neoadjuvant chemotherapy followed by radical cystectomy is the recommended standard of care for muscle-invasive bladder cancer patients who are eligible for cisplatin. Achieving a pathologic complete response in radical cystectomy provides an excellent long-term survival advantage. Since 40% of patients have a pathologic complete response, there is a growing interest in bladder preservation as a reasonable alternative strategy for oncologic control as well as improving the quality of life in these patients. However, one must be cautious when selecting a bladder preservation strategy instead of radical cystectomy because of an inaccurate restaging approach after neoadjuvant chemotherapy related to discrepancies between clinical complete response and pathologic complete response. Hence, we comprehensively discuss some of current clinical issues associated with using clinical complete response as a surrogate marker for bladder preservation, as well as for neoadjuvant chemotherapy response, and its limitation as a predictive marker for patient selection for bladder preservation in muscle-invasive bladder cancer patients. ABSTRACT: In the surgical oncology field, the change from a past radical surgery to an organ preserving surgery is a big trend. In muscle-invasive bladder cancer treatment, neoadjuvant chemotherapy (NAC) followed by radical cystectomy (RC) is the standard of care for muscle-invasive bladder cancer (MIBC) patients eligible for cisplatin. There is a growing interest in bladder preserving strategies after NAC because good oncologic outcome has been reported for pathologic complete response (pCR) patients after NAC, and many studies have continued to discuss whether bladder preservation treatment is possible for these patients. However, in actual clinical practice, decision-making should be determined according to clinical staging and there is a gap that cannot be ignored between clinical complete response (cCR) and pCR. Currently, there is a lack in a uniform approach to post-NAC restaging of MIBC and a standardized cCR definition. In this review, we clarify the gap between cCR and pCR at the current situation and focus on emerging strategies in bladder preservation in selected patients with MIBC who achieve cCR following NAC.