Small-cell Carcinomas of the Urinary Bladder and Prostate: TERT Promoter Mutation Status Differentiates Sites of Malignancy and Provides Evidence of Common Clonality Between Small-cell Carcinoma of the Urinary Bladder and Urothelial Carcinoma

• Published in: European urology focus 2018-12, Vol.4 (6), p.880-888
• Main Authors: Priemer, David S, Wang, Mingsheng, Zhang, Shaobo, Lopez-Beltran, Antonio, Kouba, Erik, Montironi, Rodolfo, Davidson, Darrell D, MacLennan, Gregory T, Wang, Lisha, Osunkoya, Adeboye O, Deng, Youping, Emerson, Robert E, Cheng, Liang
• Format: Article
• Language: English
• Subjects: Aged; Bladder; Carcinoma, Small Cell - genetics; Carcinoma, Small Cell - pathology; Carcinoma, Transitional Cell - genetics; Carcinoma, Transitional Cell - pathology; Female; Histogenesis; Humans; Male; Middle Aged; Mutation; Promoter Regions, Genetic - genetics; Prostatic Neoplasms - genetics; Prostatic Neoplasms - pathology; Small-cell carcinoma; Telomerase - genetics; Telomerase reverse transcriptase (TERT); Tumor heterogeneity; Urinary Bladder Neoplasms - genetics; Urinary Bladder Neoplasms - pathology; Urology
• ISSN: 2405-4569; 2405-4569
• DOI: 10.1016/j.euf.2017.03.007

Abstract Background Small-cell carcinoma (SCC) of the urinary bladder frequently appears alongside urothelial carcinoma, suggesting common clonality. TERT promoter mutations have been recently implicated in urothelial carcinogenesis. Objective To investigate the degree to which TERT promoter mutations are involved in SCC of the urinary bladder, the linked tumorigenesis between urothelial carcinoma and SCC of the urinary bladder, and the molecular distinctions between SCC of the urinary bladder and of the prostate. Design, setting, and participants We investigated TERT promoter mutations in 53 cases of SCC of the urinary bladder and in 26 cases of SCC of the prostate using laboratory-based studies of tissue samples and clinical data. Outcome measurements and statistical analysis We measured the frequency of TERT promoter mutations in SCCs of the urinary bladder and prostate, and concordance of the mutation status between concurrent urinary bladder SCC and urothelial carcinoma. Results and limitations TERT promoter mutations were detected in 29/53 (55%) cases of urinary bladder and 0/26 (0%) cases of prostate SCC. Of 25 cases with concurrent urinary bladder SCC and non–small-cell components, all cases harbored identical TERT promoter mutation status in both phenotypes. Conclusions TERT promoter mutations are found in more than half of urinary bladder SCCs. Mutation status is also identical in urothelial carcinoma and SCC components of concomitant malignancies, providing evidence of a common clonality. TERT promoter mutation status can differentiate SCC of the urinary bladder from prostate SCC, suggesting potential diagnostic use. Patient summary Small-cell carcinoma of the urinary bladder shares a common clonal origin with conventional urothelial carcinoma and may arise from a heterogeneous subclone. TERT promoter mutations may have utility as a differential biomarker for determining the primary site of a genitourinary small-cell carcinoma.