Comparative distribution of HPV genotypes in penile and vulvar squamous cell carcinomas with basaloid or warty (condylomatous) features.

Current paradigm is the classification of penile and vulvar carcinomas in HPV-associated and HPV-independent. About 30-50 % of invasive carcinomas at both sites are HPV-associated. The aim of the study was to compare HPV genotypes in both neoplasias. HPV positive invasive penile (161 cases) and vulvar (221 cases) carcinomas were evaluated. They were pathologically classified as basaloid, warty-basaloid and warty carcinomas. HPV detection and genotyping of whole tissue sections was done using SPF-10/DEIA/LiPA25 system (version 1). The distribution of HPV-associated subtypes of invasive penile and vulvar carcinomas was similar. Twenty-one HPV genotypes were identified, 16 and 15 in penile and vulvar sites, respectively. HPV16 was equally frequent (80 vs 76%). Genotypes other than HPV16 shared by both tumors were HPVs 18, 31, 33, 45, 52, 53, 56, 58 and 73. There were, however, dissimilarities in HPV genotype distribution. HPVs 6, 35, 51, 55, 59 and 74 were found only in our penile cohort, whereas HPVs 11, 26, 30, 39, 44 were unique to our vulvar both tumors were HPVs 18, 31, 33, 45, 52, 53, 56, 58 and 73. Most HPV genotypes corresponded to those covered by current vaccines. HPV genotypes not covered by current HPV vaccines were 8 and 7 in penile and vulvar tumors, respectively, representing 10 and 7% of all patients in each category. However, there were genotypes identified only in our penile (6 of 21, 29%) and vulvar (5 of 21, 24%) tumors cohort. The differences found would have a minimal impact on current vaccination programs, which would cover around 90 and 93% of penile and vulvar cancer patients, respectively.