Association between surgical volume and survival among patients with variant histologies of bladder cancer.

To examine the relationship between hospital volume and the management of bladder cancer variant histology. Variant histologies of bladder cancer are rare which limits the ability for providers to develop expertise however there is a clear hospital/surgeon-volume relationship for management of rare or complex surgical/medical diseases.

We queried the National Cancer Database from 2004 to 2016 for all cases of bladder cancer, identifying cases of variant histology. Our primary outcome was overall survival while secondary outcomes included identifying treatment patterns. Hospitals were stratified into those that managed ≤2, >2-4, >4-6 and ≥6 cases per year of variant histology.

We identified 23,284 patients with bladder cancer of variant histology who were treated at 1,301 hospitals. Few institutions had high volume experience with this disease: 18.5% (n = 241) treated >2 patients annually and 5.7% (n=76) treated >4 cases annually. Hospital volume positively correlated with utilization of early radical cystectomy (RC) in non-muscle invasive disease and neoadjuvant chemotherapy in muscle-invasive disease. On multivariable analysis, increased hospital volume was associated with improved survival. After stratifying by sub-type, hospital volume continued to be associated with improved survival for squamous, small cell and sarcomatoid cancers.

Management of variant histology urothelial carcinoma at high-volume centers is associated with improved overall survival. The mechanisms of this are multifactorial, and future research should focus on improvement opportunities for low-volume hospitals, centralization of care and/or increased access to care at high-volume centers.

Urology. 2021 Oct 01 [Epub ahead of print]

Wilson Sui, Mary E Hall, Daniel A Barocas, Sam S Chang, Amy N Luckenbaugh, Kelvin A Moses, David F Penson, Christopher J D Wallis, Aaron A Laviana

Department of Urology, Vanderbilt University Medical Center, Nashville, TN., Department of Surgery & Perioperative Care, Dell Medical School at the University of Texas at Austin, Austin, TX. Electronic address: .