Human papillomavirus genotyping in high-grade vaginal intraepithelial neoplasia: A multicentric Italian study

This study aimed to analyze the human papillomavirus (HPV) genotype distribution in a large cohort of high-grade vaginal intraepithelial neoplasia (VaIN) (vaginal HSIL, VaIN2/3) patients from two Italian referral centers. We included all patients with histologically confirmed VaIN2/3 from the Department of Surgical Sciences, Sant'Anna Hospital, University of Torino, Torino, Italy, and Ospedale Maggiore della Carità, Novara, Italy, between 2003 and 2022. After the histological evaluation of formalin-fixed paraffin-embedded samples, we performed HPV genotyping with VisionArray HPV Chip 1.0. We detected HPV DNA in 94.4% of VaIN2/3 (168/178), with HPV 16 as the most prevalent genotype, accounting for 51.8% of all infections, 41.2% of VaIN2 and 77.6% of VaIN3 cases. Other frequent genotypes were HPV 58 (8.3%, 10.9% of VaIN2 and 2.0% of VaIN3), HPV 73 (5.4%, 5.0% of VaIN2 and 6.1% of VaIN3), and HPV 31 (5.4%, 6.7% of VaIN2 and 2.0% of VaIN3). 73.2% of VaIN2/3 had a single HPV genotype infection and 26.8% a multiple infection (20.8% a double infection, 4.8% a triple infection, and 1.2% a quadruple infection). Single infection was more frequently present in VaIN3 than VaIN2 (81.6% vs. 69.8%). 69.1% of single infections and 73.3% of multiple infections had one or more genotypes covered by nine-valent HPV vaccine. HPV vaccination is expected to have a large impact on reducing the incidence of vaginal intraepithelial neoplasia.