Selective bladder preservation with curative intent for muscle-invasive bladder cancer: a contemporary review

Radical cystectomy plus urinary diversion, the reference standard treatment for muscle-invasive bladder cancer, associates with high complication rates and compromises quality of life as a result of long-term effects on urinary, gastrointestinal and sexual function, and changes in body image. As a society ages, the number of elderly patients unfit for radical cystectomy as a result of comorbidity will increase, and thus the demand for bladder-sparing approaches for muscle-invasive bladder cancer will also inevitably increase. Trimodality bladder-sparing approaches consisting of transurethral resection, chemotherapy and radiotherapy (Σ 55-65 Gy) yield overall survival rates comparable with those of radical cystectomy series (50-70% at 5 years), while preserving the native bladder in 40-60% of muscle-invasive bladder cancer patients, contributing to an improvement in quality of life for such patients. Limitations of the trimodality therapy include (i) muscle-invasive bladder cancer recurrence in the preserved bladder, which most often arises in the original muscle-invasive bladder cancer site; (ii) potential lack of curative intervention for regional lymph nodes; and (iii) increased morbidity in the event of salvage radical cystectomy for remaining or recurrent disease as a result of high-dose pelvic irradiation. Consolidative partial cystectomy with pelvic lymph node dissection followed by induction chemoradiotherapy at lower dose (e.g. 40 Gy) is a rational strategy for overcoming such limitations by strengthening locoregional control and reducing radiation dosage. Molecular profiling of the tumor and functional imaging might play important roles in optimal patient selection for bladder preservation. Refinement of radiation techniques, intensified concurrent or adjuvant chemotherapy, and novel sensitizers, including molecular targeting agent, are also expected to improve outcomes and consequently provide more muscle-invasive bladder cancer patients with favorable quality of life.