Human papillomavirus infection and anal carcinoma. Retrospective analysis by in situ hybridization and the polymerase chain reaction.

To examine the association of human papillomavirus (HPV) infection with anal squamous cell carcinoma, the authors applied the highly sensitive polymerase chain reaction (PCR) and in situ hybridization (ISH) techniques to detect HPV DNA in formalin-fixed, paraffin-embedded tissues from 18 patients. The presence of HPV types 16/18 in 3 (16.7%) of 18 patients with anal carcinoma was found, using a colorimetric ISH technique for HPV types 6, 11, 16, 18, 31, 35, and 51. Results from one of these three patients were also positive for HPV 31, 35, 51 by ISH techniques. When the same series was analyzed using the PCR and consensus primers to the L1 open reading frame of the HPV genomes, the frequency of positive patients rose to 14 (77.8%) of 18. PCR analysis of the 14 lesions containing HPV DNA, using type-specific primers and probes for HPV 6, 11, 16, 18, and 33, showed that 1 contained HPV 6, 1 contained HPV 11, 4 contained HPV 16, 1 contained HPV 18, 1 contained HPV 33, 5 contained HPV of unclassified type(s), and 1 contained a mixture of three HPV types. There was concordance between typing of cases that were positive by ISH and PCR methods. These data agree with the concept that HPV, in particular type 16, is implicated in the pathogenesis of anal cancer.