PROPERTIES OF HPV-POSITIVE AND HPV-NEGATIVE ANAL CARCINOMAS

Evidence of human papillomavirus (HPV) can be found in up to 85 per ce nt of anal carcinomas, In the vulva, a discrete subset of HPV-positive carcinomas which show koilocytic morphology and distinct clinical fea tures has recently been identified (warty carcinoma), The morphologica l and prognostic features of HPV-positive and HPV-negative anal carcin omas mere compared in this study of the tumour distribution of HPV DNA , Vulval and anal neoplasia are similar in many ways and we have also looked to see if their similarity extends to 'warty' morphology in rel ation to HPV status, Thirty-five resection specimens of anal carcinoma were examined with biotin-labelled probes for HPV 6, 11, 16, and 18 D NA, using a non-isotopic in situ hybridization (ISH) technique, No tum our was found to contain HPV 6, 11, or 18, Twenty-four (72 per cent) s howed positivity for HPV 16 DNA, Staining was homogenous and independe nt of local squamous, basaloid, or ductal differentiation. The majorit y of tumours showed staining suggestive of episomal, non-productive HP V infection, HPV-positive tumours were more likely to occur in the ana l canal than perianally and to show a mixed squamous and basaloid appe arance, No difference between the two groups was found in patient age, presence of adjacent dysplasia, ductal differentiation, or prognosis, There was no correlation between condylomatous tumour morphology and HPV 16 DNA positivity; thus, a subset equivalent to vulval warty carci noma could not be identified.