Human papillomavirus and urinary bladder cancer revisited.

This review aims to present data on the association between human papillomavirus (HPV) and urinary bladder cancer (BC), especially of the subtype squamous cell carcinoma (SCC). Furthermore, the current data on the relation between p16, HPV, and BC are reviewed. PubMed was searched for 'Humans' [MESH] AND 'Papillomaviridae' [MESH] AND 'Urinary Bladder Neoplasms' [MESH], resulting in 157 potential articles. After profound reviewing, 18 articles were included in this review. Only original articles in English were included. A variable number of HPV genotypes in a small number of cases have been investigated in several studies with various methodology. HPV was present in 0-100% of cases depending on inclusion and exclusion criteria. SCC studies are mostly hampered by low number of cases whereas the few studies with a high number show a slightly higher prevalence of different HPV genotypes compared to pure urothelial carcinoma. Studies on p16 status in HPV positive cases are even more scarcely reported and show conflicting results. Most studies fail to prove clear-cut relevance of HPV in BC irrespectively of histological subtype. Negative p16 staining cannot rule out positive HPV status.