Adjuvant radiotherapy following radical cystectomy in patients with muscle-invasive bladder cancer: a narrative review.

PURPOSE OF REVIEW

This review aims to synthesize emerging evidence on the role of adjuvant radiotherapy (RT) following radical cystectomy (RC) for muscle-invasive bladder cancer (MIBC).

RECENT FINDINGS

A randomized trial comparing adjuvant chemoradiotherapy to chemotherapy alone in 125 MIBC patients demonstrated a significant improvement in 2-year local recurrence- free survival (LRFS) (96% vs. 69%; P  < 0.01). Three studies have evaluated adjuvant RT alone. A single-arm study reported a 5-year local control rate of 79% among 72 patients, with 17% experiencing serious gastrointestinal (GI) adverse events (AEs). A randomized controlled trial (RCT) involving 122 patients found improved 3-year LRFS in the RT arm (81% vs. 71% at three years; P  = 0.046), with low rate of severe GI AEs (3%); however, the survival difference was not statistically significant. Another RCT with 153 patients showed similar rates of acute severe AEs between RT and observation groups (1.6% vs. 4.2%; P  = 0.34). Key limitations across studies include heterogeneity in design, lack of statistical power to detect survival differences, limited patient-reported outcome data, and absence of direct comparisons with immune checkpoint inhibitors - the current standard of care in the adjuvant setting.

SUMMARY

Modern adjuvant RT appears to be associated with acceptable toxicity, likely due to improved delivery techniques. Although data suggest a benefit in local-regional control, an overall survival advantage has not been demonstrated. Adjuvant RT may be considered in selected high-risk patients, particularly in settings where access to salvage therapies or immunotherapy is limited.