Anal human papillomavirus infection and abnormal anal cytology in women with genital neoplasia

Objectives: Describe the type-specific prevalence of anal HPV infection in women with lower genital tract intraepithelial neoplasia and cancer. Describe the prevalence of abnormal anal cytology and identify risk factors for anal HPV infection and abnormal anal cytology in this population. Methods: We performed a cross-sectional study of women attending 2 university-based colposcopy clinics with high-grade lower genital tract intraepithelial neoplasia or cancer. Participants received anal HPV testing/typing, anal cytology and completed a questionnaire detailing medical history and sexual behavior. Results: Of the 102 women enrolled, 92 (90%) had adequate β-globin for analysis of HPV DNA status, and 47/92 women (51%) had detectable anal HPV. Of the 15 HPV types identified, 9 (60%) were oncogenic types and 6 (40%) were non-oncogenic or undetermined risk types. Overall, 9 women (9%) had abnormal anal cytology, and 7 of those had corresponding anal intraepithelial neoplasia grade I (AIN I). Women with vulvar disease had the highest proportion of abnormal anal cytology (21%) compared to women with cervical disease alone (7%), but this difference was not statistically significant (p = 0.10). Neither anal HPV infection nor abnormal cytology was significantly associated with anal sex practices, smoking or number of sexual partners. Conclusions: Anal infection with high-risk HPV types is common in women with high-grade genital neoplasia, but was not associated with known risk factors for genital HPV infection. Other unidentified risk factors may play a role in the anal HPV infection in this population. Abnormal anal cytology was rare and larger studies are needed to identify risk factors associated with abnormal cytology and anal intraepithelial neoplasia in this population.