Human papillomavirus types in non-cervical high-grade intraepithelial neoplasias and invasive carcinomas from San Luis Potosí, Mexico: a retrospective cross-sectional study

BACKGROUND: Viral infections and the burden of high-grade intraepithelial neoplasias (HIN) and invasive carcinomas (IC) associated to infections by human papillomavirus (HPV) types may be prevented by type-specific anti-HPV vaccines. This study determined the prevalence of HPV types in non-cervical HIN and IC diagnosed from 1999 to 2011 at a general hospital in San Luis Potosí, Mexico. METHODS: Review of the 67 formaldehyde-fixed paraffin-embedded non-cervical specimens initially diagnosed as HIN (n = 28) or IC (n = 39) confirmed the presence of tumor tissue in 63 of them and changed the diagnosis of 24 from HIN to low-grade intraepithelial neoplasias, that were excluded from the study. HPV DNA was detected with the SPF10-DNA enzyme immunoassay in the 39 cases included, and viral types in the HPV-positive tumors were identified with the INNO-LiPA linear probe array. RESULTS: Among the cases included, four HIN were located in the vagina (n = 3) and vulva (n = 1), and 35 IC in the oral cavity (n = 19), penis (n = 8), vagina (n = 7) and vulva (n = 1). There were 13 HPV-positive cases from the vagina (n = 7), vulva (n = 1), penis (n = 1) and oral cavity (n = 1). The viral types identified were the high-risk types HPV16 in the vagina (n = 3) and vulva (n = 3), HPV45 in the vagina (n = 2), HPV59 in the vagina (n = 1) and penis (n = 1), HPV33 in the vagina (n = 1),and HPV35 in the tongue(n = 1); and the low-risk types HPV54 in the vagina (n = 1), and HPV11 in the vulva (n = 1). CONCLUSIONS: Five high-risk viral types (HPV16, 45, 59, 33 and 35) and two low-risk types (HPV11 and 54) infect one third of the non-cervical HIN and IC included. Most infections are by a single HPV high-risk type, the most prevalent one being HPV16. Vagina is the most frequent location of the HPV-positive tumors. Vaccination against HPV16 and HPV18 could have prevented around half of the HPV-positive tumors.