Incidence and effect of variant histology on oncological outcomes in patients with bladder cancer treated with radical cystectomy

We sought to describe incidence of histological variants after radical cystectomy (RC) due to bladder cancer (BCa). Moreover, we investigated survival outcomes accounting for this parameter.

We retrospectively evaluated data from 1,067 patients with BCa treated with RC between 1990 and 2013 at a single tertiary care referral center. All specimen were evaluated by dedicated uropathologists. Univariable and multivariable Cox regression analyses tested the effect of different histopathological variant on recurrence, cancer-specific mortality (CSM), and overall mortality (OM) after accounting for all available confounders.

Of 1,067 patients, 729 (68.3%) harbored pure urothelial BCa while 338 (31.7%) were found to have a variant. Considering uncommon variants, 21 (2.0%) were sarcomatoid, 10 (0.9%) lymphoepitelial, 19 (1.8%) small cell, 109 (10.2%) squamous, 89 (8.3%) micropapillary, 23 (2.2%) glandular, 34 (3.2%) mixed variants, and 33 (3.1%) were found with other types of variants. With a median follow-up of 6.2 years, 343 recurrence, 365 CSM, and 451 OM were recorded, respectively. At multivariable Cox regression analyses, the presence of small cell variant was associated with higher recurrence (hazard ratio [HR] = 3.47, P<0.001), CSM (HR = 3.30, P<0.04), and OM (HR = 2.97, P<0.003) as compared with pure urothelial cancer. Conversely, no survival differences were recorded considering other histological variants (all P> 0.1).

Our study confirms that histological variant is not an infrequent event at RC specimen. However, in our single-center series, only patients found with small cell variant were associated with a negative effect on survival after RC.

Urologic oncology. 2017 Jan 10 [Epub ahead of print]

Marco Moschini, Paolo Dell'Oglio, Roberta Luciano', Giorgio Gandaglia, Francesco Soria, Agostino Mattei, Tobias Klatte, Rocco Damiano, Shahrokh F Shariat, Andrea Salonia, Francesco Montorsi, Alberto Briganti, Renzo Colombo, Andrea Gallina

Department of Urology, IRCCS Ospedale San Raffaele, URI Milan, Italy; Department of Urology, Magna Graecia University of Catanzaro, Catanzaro, Italy; Department of Urology, Medical University of Vienna, Vienna, Austria. Electronic address: ., Department of Urology, IRCCS Ospedale San Raffaele, URI Milan, Italy., Department of Pathology, Ospedale San Raffaele, Milan, Italy., Department of Urology, Medical University of Vienna, Vienna, Austria., Klinik Für Urologie, Luzerner Kantonsspital, Lucerne, Switzerland., Department of Urology, Magna Graecia University of Catanzaro, Catanzaro, Italy.