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

Abstract 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.