Low frequency of human papillomavirus infection in initial papillary bladder tumors

The involvement of human papillomavirus (HPV) in bladder cancer remains controversial. We previously reported detection of L1-HPV DNA in 39% of bladder cancers of mixed grade and stage. To clarify the possible etiologic role of HPV we studied, using the same technique, a more homogeneous group of initial low-stage tumors. We investigated a total of 187 newly diagnosed superficial papillary bladder tumors for the presence of L1-HPV DNA by the polymerase chain reaction method and hybridization with specific probes for HPV 6, 11, 16, 18, 33. HPV DNA was detected in 16 (8.5%) of the 187 specimens tested, although in a low copy number compared with SiHa cervical cancer cells used as control. HPV type 16 was observed in eight tumors while HPV type 6 and type 11 were each observed in three tumors. Two tumor specimens contained two types of HPV: one tumor hybridized with type 6 and 16 and the other with type 11 and 18. This low rate of HPV detection (8.5%) in initial tumors does not favor a prominent role for HPV in bladder carcinogenesis.