Human papillomavirus (HPV) profiles of vulvar lesions: possible implications for the classification of vulvar squamous cell carcinoma precursors and for the efficacy of prophylactic HPV vaccination.

The term vulvar intraepithelial neoplasia (VIN) introduced in 1986 incorporates 3 grades of usual VIN (u-VIN I-III) and the differentiated VIN (d-VIN). Although u-VIN is etiologically associated with the human papillomavirus (HPV) infection, d-VIN represents an alternative HPV negative pathway of vulvar carcinogenesis. In 2004, the u-VIN I category was abandoned and u-VIN II and III were merged. Further, an alternative Bethesda-like terminology scheme presenting the term vulvar intraepithelial lesion was proposed recently. To analyze the impact of HPV profiles of vulvar precancerous lesions for their classification and to assess the presumable efficacy of the prophylactic HPV vaccination, 269 vulvar excisions representing lichen sclerosus, lichen simplex chronicus, condylomata acuminata, d-VIN, all grades of u-VIN and squamous cell carcinomas were subjected to the HPV typing by use of GP5+/6+ polymerase chain reaction and reverse line blot hybridization. The results showed different HPV profiles, and also differing frequency of multiple-type HPV infection and the age structure in patients with u-VIN II and III. The biologic heterogeneity within the u-VIN II category was also demonstrated. u-VIN I was distinguished as a rare disorder associated with high-risk HPV infection. We conclude that the original VIN terminology proposed in 1986 seems to be appropriate for the classification of vulvar squamous dysplastic lesions. The spectrum of HPV types found in vulvar squamous cell carcinomas indicates that the efficacy of HPV vaccination in preventing vulvar cancer might be diminished in the studied population, because the recently developed prophylactic vaccines are targeted against a limited number of HPV types.