SAN DIEGO—Bladder preservation therapy is associated with decreased overall survival compared with radical cystectomy among patients with muscle-invasive bladder cancer (MIBC), according to study findings presented at the American Urological Association 2016 annual meeting.

Using the National Cancer Data Base, investigators at Fox Chase Cancer Center in Philadelphia identified 54,518 patients diagnosed with analytic stage II–III urothelial carcinoma of the bladder from 2003 to 2011. Of these, 27,843 patients underwent radical cystectomy (RC) or received bladder preservation therapy (BPT): 19,745 RC (70.9%) and 8,098 BPT (29.1%). The researchers stratified the BPT patients into 3 cohorts based on increasingly stringent definitions: any external beam radiotherapy (EBRT, 58.1%), definitive radiotherapy (RT) of 50–80 Gy (26.9%), and definitive RT plus chemotherapy administered within a 3-month time frame (15%). BPT patients typically were older, had worse Charlson comorbidity indices, and were not treated at academic centers, he noted.

In adjusted analyses, RC was associated with improved overall survival compared with BPT, but use of increasingly stringent definitions of BPT attenuated the observed the difference in overall survival, said David Cahn, MD, who reported the study findings. EBRT, definitive RT, and definitive RT plus chemotherapy were associated with a 2.2-fold, 1.9-fold, and 1.56 fold increased risk of death compared with RC, he said.

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Results shows a statistically significant increase in optimal bladder preservation—maximal transurethral resection followed by concurrent radiotherapy and chemotherapy—during the study period, but given the large sample size, the absolute increase was only about 2.4%, Dr. Cahn said.

“These findings and trends may be due to inferior cancer control, measured or unmeasured confounding selection biases, or a combination of both factors,” Dr. Cahn told attendees.