Bertoli HK, et al. - Authors classified studies published between 1986 and 2017 using PCR-based or Hybrid Capture 2 tests to estimate the presence of HPV DNA and/or using any method to identify p16 overexpression in vaginal intraepithelial neoplasia (VaIN), vaginal squamous cell carcinoma (VaSCC), or other types of vaginal cancer. They used I² statistic to evaluate the heterogeneity. They noted pooled HPV prevalences in VaSCC and VaIN, 66.7% and 85.2%, respectively. They observed HPV16, followed by HPV33, and HPV45 (in VaIN) and HPV18, and HPV33 (in VaSCC) as the most prevalent HPV type among the HPV positive VaSCC and VaIN cases. They noted that 38.9% of HPV negative and 89.9% of HPV positive vaginal cancers were positive for p16 overexpression. They suggested that a substantial proportion of vaginal neoplasia could be prevented by vaccination against HPV.