Papillomavirus DNA in basal cell carcinomas of immunocompetent patients: An accidental association?

DNA of human papillomaviruses has frequently been detected in nonmelanoma s kin cancers, raising the question of a possible causal contribution of thes e tumor viruses to skin carcinogenesis. Basal cell carcinomas are the most common nonmelanoma skin cancers; however, so far they are only poorly analy zed with regard to human papillomavirus infection. We searched for human pa pillomavirus-DNA in 69 biopsies from 61 immunocompetent basal cell carcinom a patients from two geographic locations in Europe using six different poly merase chain reaction primer systems. We could demonstrate human papillomav irus-DNA in 43.5% of the tested tumors. Human papillomavirus positivity did not seem to correlate with the duration of disease or patients' age. The v ast majority of virus types in the biopsies belonged to the group of epider modysplasia verruciformis-associated human papillomavirus. Of 31 sample pai rs tested for human papillomavirus-DNA in tumors as well as in perilesional healthy skin, seven carried viral sequences in lesional and healthy skin a nd three only in the basal cell carcinoma. Six of the seven human papilloma virus-positive basal cell carcinoma/healthy skin pairs contained identical human papillomavirus types in tumors and histologically normal tissue. Fort y basal cell carcinoma patients were additionally analyzed for IgG antibodi es against virus-like particles of three representative epidermodysplasia v erruciformis-human papillomavirus types: 8, 15, and 36. No statistically si gnificant differences could be detected between human papillomavirus antibo dy prevalences of basal cell carcinoma patients and of dermatologically hea lthy individuals. Moreover, serologic findings did not correlate with the d etection of specific human papillomavirus types in tumors. Our results seem to suggest that the occurrence of human papillomavirus-DNA in basal cell c arcinoma does not reflect a major etiologic role of human papillomavirus in this cancer.