Bladder-sparing approaches for muscle invasive bladder cancer: a narrative review of current evidence and future perspectives

BACKGROUND AND OBJECTIVE: In recent years, the application of less-invasive “bladder-sparing” trimodal therapy (TMT) in selected muscle-invasive bladder cancer (MIBC) patients unfit for or who declined radical cystectomy (RC) has been increasing. This review aims to summarize the current evidence and future perspectives of bladder-sparing therapy for MIBC. METHODS: A non-systematic Medline/PubMed literature search was conducted on July 2022 with the following keywords ‘MIBC’, ‘bladder-sparing’, ‘chemotherapy’, ‘radiotherapy’, ‘trimodal’, ‘multimodal’, and ‘immunotherapy’. KEY CONTENT AND FINDINGS: All monotherapies are inferior to RC or combination therapy and should not be routinely used for curative intent. Radiotherapy (RT) alone has been shown to have poorer outcomes when compared to chemoradiotherapy. The ideal selection criteria for TMT include good bladder function and capacity, clinical stage within cT2, complete transurethral resection of bladder tumor (TURBT), no prior history of pelvic RT, no extensive carcinoma in situ (CIS), and absence of hydronephrosis. The emergence of immunotherapy may further increase the effect of bladder-sparing therapy. Novel predictive biomarkers are awaited for more precise patient selection and better oncological outcomes. CONCLUSIONS: TMT is a well-tolerated and offers a curative alternative approach to RC for selected patients with localized MIBC. Appropriate patient selection and a multi-disciplinary approach is crucial in achieving good oncologic control with bladder-sparing therapy.