Prevalence of Anal Intraepithelial Neoplasia in Women With Genital Neoplasia

BACKGROUND: Anal intraepithelial neoplasia is believed to be a precursor of anal cancer, and it appears to be related to high-risk human papillomavirus. Women with genital neoplasia have been shown to be at increased risk for anal cancer. OBJECTIVE: The aim of this study is to determine the prevalence of anal intraepithelial neoplasia in women with genital neoplasia. DESIGN: This is a cross-sectional study. SETTING: This study took place at Hospital Nossa Senhora da Conceicao, Porto Alegre, Brazil, from May 2008 to April 2010. PATIENTS: Included in the study were 106 immunocompetent women with a histopathological diagnosis of genital neoplasia and 74 women without gynecologic neoplasia. MAIN OUTCOME MEASURE: All women underwent high-resolution anoscopy with biopsies of acetowhite areas or abnormal vascular features such as punctation and mosaics for histopathological diagnosis of anal intraepithelial neoplasia. RESULTS: The overall prevalence of anal intraepithelial neoplasia was 6.6%. In women with genital neoplasia, the prevalence was 10.4% (95% CI, 5.6%-17.3%), whereas the prevalence was 1.4% (95% CI, 0.07%-6.5%) in women without genital neoplasia (P=.016). The prevalence ratio was 7.68 (95% CI, 1.01-58.21). LIMITATION: Women with normal results on high-resolution anoscopy were not submitted to random biopsies for ethical reasons. Small lesions could be missed, and thus our findings might be underestimated. CONCLUSION: The prevalence of anal intraepithelial neoplasia is higher in women with genital neoplasia.