Update on Bladder Preservation Therapies for Muscle-Invasive Bladder Cancer

Update on Bladder Preservation Therapies for Muscle-Invasive Bladder Cancer

Standard management of muscle-invasive bladder cancer (MIBC) entails radical cystectomy (RC) with the removal of bilateral pelvic lymph nodes. Adding neoadjuvant chemotherapy to standard management has been shown to increase absolute survival by 5% at 5 years. Although RC with bilateral pelvic lymph node dissection (PLND) remains the standard of care for the majority of patients with MIBC, the procedure is associated with high morbidity and mortality. These concerns have sparked investigations into therapies that preserve the bladder. Patients who have sought bladder preservation typically fall into two categories: 1) patients who are medically inoperable and unfit for surgery, or 2) patients with cancer confined to the bladder who wish to avoid radical surgery.

The ideal candidates for bladder preservation include those with small solitary tumors (less than 5cm), no lymph node metastases, no carcinoma in situ (CIS), no hydronephrosis, and with favorable bladder function at baseline. Various unimodal and multimodal therapies exist for bladder preservation in the setting of MIBC (Table 1). Trimodal therapy (TMT)—maximal transurethral resection of bladder tumor (mTURBT), chemotherapy, and radiation therapy—is the bladder preservation therapy with the most evidence for use.  In carefully selected patients, TMT has shown comparable efficacy to RC in treating MIBC.

As opposed to RC, partial cystectomy (PC) affords bladder preservation while maintaining the ability to carefully assess surgical margins and perform PLND if necessary. Although early PC series demonstrated poor outcomes, latter PC series with more selective inclusion criteria showed outcomes comparable to RC. Because of the possibility of local recurrence after PC due to remaining foci of disease, combinations with other treatment modalities have been investigated. Tetramodal therapy involves maximal TURBT followed by chemoradiation and consolidative PC and has been shown to be highly efficacious, although in studies with smaller sample size.

Any discussion of bladder preservation therapy must also include quality of life considerations. Adverse outcomes related to TMT are largely gastrointestinal and genitourinary but are likely underreported given inconsistent use of patient-reported outcomes in trials. Notably, TMT trials have shown a superior patient-reported quality of life and an increase in quality-adjusted life years as compared to RC.