Do histological variants in urothelial carcinoma of the bladder portend poor prognosis? A systematic review and meta-analysis.

The clinical implications of histological variants in urothelial carcinoma of the bladder has been a subject of significant controversy with many unanswered questions that remain. To clarify whether histological variants presage poor prognosis for patients suffering from urothelial carcinoma of the bladder, we scoured through various electronic databases such as Medline, Web of Knowledge, and the Cochrane Library up to August 18, 2016. Experts were consulted, and references from relevant articles were scanned. We identified thirteen eligible studies which met the inclusion criteria, including 9,533 participants. The existing evidence indicates that histological variants in urothelial carcinoma of the bladder patients do not alter their prognosis.