HPV DNA in oropharyngeal squamous cell cancers: comparison of results from four DNA detection methods

Oropharyngeal squamous cell cancers (SCCs) were examined for human papillomavirus (HPV) related DNA sequences. The techniques employed were Southern blotting under stringent and non stringent conditions, dot blotting, primer directed gene amplification using the polymerase chain reaction (PCR), and in-situ hybridization. HPV 16 DNA was found in 4 of 30 tumor samples using PCR. HPV 16 DNA was found in 2 further tumors using in-situ hybridization. No HPV DNA could be found by Southern blot or dot blot in any tumor sample. The Southern blot assays were sensitive enough to detect clonally integrated HPV 16 DNA of length greater than 250 bp in the tumors. While HPV DNA is present in some oropharyngeal SCCs, there is no molecular evidence to support a causal association of HPV 16 gene products with continued tumor growth in oropharyngeal cancer.