Clinical Management of Anogenital Warts and Intraepithelial Neoplasia

Abstract

The Human Papilloma Virus is the most common sexually transmitted infection worldwide. More than 200 different genotypes have been identified so far, and they are classified in five genera (Alpha, Beta, Gamma, Mu and Nu) [1]. Most of the infections caused by these types are transient and asymptomatic, since they are rapidly cleared by an intact immune system. However, HPV may cause clinical manifestations of variable severity. About 40 mucosal genotypes have been associated with the development of anogenital lesions [2]. These span from benign warts (condylomata), mainly caused by the low-risk HPV 6 and 11, to cancerous lesions, caused by high-risk (HR) types (e.g., HPV 16 and 18). Indeed, HR-HPV are implicated in the development of most cervical (close to 90% of the cases), anal (andgt;80%), vulvar (around 40%), vaginal (around 70%), penile (around 50%) and oropharyngeal (13–56%) cancers. Because of the ascertained link between anal HPV infection and anal cancer development, and, in particularly, the increasing incidence of this neoplasia over the last years, the interest on the burden of anal HPV infection has been growing. Indeed, about 88% of anal cancer cases worldwide are associated with HPV infection 2. HPV 16 (75–80%) and HPV18 (about 3.5%) represent the most prevalent types in this neoplasia [3]. Most sexually active persons will have detectable HPV at least once in their lifetime [4]. The estimated incidence of HPV infection is high, with 14 million persons infected annually and 79 million persons with prevalent infection [5]. In the last years it emerged that in Italy the anogenital warts were more frequent (40,871 cases, 39.7% of the total) among other sexually transmitted diseases as latent syphilis (9190 cases, 8.9% of the total), bacterial cervicovaginitis (8798 cases, 8.5% of the total) and genital herpes (7860 cases, 7.6% of the total). In particular the anogenital warts were the most frequent pathologies among men (30,092 cases, 41.5% of total men) (http://www.iss.it/ccoa/index.php?lang=1andid=55andtipo=4). HPV-associated diseases include anogenital and other mucocutaneous warts as well as cervical, anal, vaginal, vulvar, penile and oropharyngeal cancer [1]. Anogenital warts (AGWs) (also known as genital warts, condylomata acuminata, condylomas) are benign proliferative lesions caused by human papillomavirus (HPV) types 6 and 11, which are found in andgt;95% of lesions [1, 6]. AGWs are often co-infected with “‘high-risk” HPVs such as HPV 16–18. Genital warts are sexually transmitted, with transmission rates of about 60% between partners [7].