Anal and cervical intraepithelial neoplasia: possible parallel

Area of Science:

• Gastroenterology
• Oncology
• Virology

Background:

• Premalignant anal lesions, such as anal intraepithelial neoplasia (AIN), are increasingly recognized.
• Human papillomavirus (HPV) infection is a known risk factor for cervical intraepithelial neoplasia (CIN) and is implicated in AIN development.

Purpose of the Study:

• To prospectively evaluate the efficacy of endoscopic examination for detecting AIN.
• To investigate the association between HPV infection and the prevalence of AIN.
• To compare AIN prevalence in different risk groups, including homosexual and heterosexual men, and women with and without CIN.

Main Methods:

• Prospective study involving endoscopic examination of the anal canal.
• Anal epithelial biopsies were performed and examined histologically.
• Human papillomavirus (HPV) DNA hybridization was conducted on biopsy samples.

Main Results:

• No AIN was detected in 20 control patients with anal fissure or fistula.
• Of 82 patients with anal HPV infection, 23 (28%) showed evidence of AIN.
• AIN prevalence was significantly higher in homosexual men (17/28) compared to heterosexual men (1/26) with anal HPV infection.
• Among 28 women with anal HPV infection, 10 had concurrent CIN; 5 of these also had AIN, and no woman had AIN without CIN.

Conclusions:

• Anal intraepithelial neoplasia (AIN) is a diagnosable condition using endoscopic methods, analogous to cervical intraepithelial neoplasia (CIN).
• HPV infection is strongly associated with AIN, with higher prevalence noted in specific risk groups.
• Further research into the natural history of AIN and identification of at-risk populations are warranted.