Ideal candidates for bladder preservation in muscle-invasive bladder cancer.

Muscle-invasive bladder cancer (MIBC) is an aggressive malignancy traditionally treated with radical cystectomy (RC) and perioperative systemic therapy. While this approach provides effective oncologic control, RC is associated with significant perioperative morbidity and may not be suitable for patients with advanced age, comorbidities, or frailty. Bladder-preserving strategies, particularly trimodality therapy (TMT), consisting of maximal transurethral resection of bladder tumor followed by definitive radiotherapy with concurrent radiosensitizing systemic therapy, have emerged as a curative-intent alternative in appropriately selected patients. This narrative review synthesizes contemporary clinical evidence, major guideline recommendations, and emerging data regarding patient selection for bladder preservation in MIBC. Favorable outcomes with TMT are most observed in patients with lower clinical tumor stage, absence of extensive nodal disease, no untreated hydronephrosis, and the ability to achieve maximal transurethral resection. Tumor characteristics such as multifocal disease, carcinoma in situ, and variant histology require individualized consideration but are not absolute contraindications. Patient-related factors including performance status, baseline bladder function, renal function, and the capacity to adhere to intensive surveillance are also important for optimal outcomes. Emerging data suggest that selected patients with limited nodal disease or higher local stage may achieve outcomes comparable to cystectomy-based approaches. Advances in systemic therapies, including immunotherapy and antibody-drug conjugates, may further expand eligibility for bladder-preserving strategies. Overall, TMT represents an established organ-preserving treatment option for carefully selected patients with MIBC when delivered within a multidisciplinary framework with high-quality local therapy and rigorous post-treatment surveillance.