Anal Intraepithelial Neoplasia Screening in Women from the Largest Lower Genital Tract Disease Center of China

Purpose: ：This study aimed to provide comprehensive clinical screening data on anal intraepithelial neoplasia (AIN) and anal squamous cell carcinoma (ASCC). Methods: : The study from 304 patients who underwent high-resolution anoscopy (HRA) examinations between January 1, 2020, and October 30, 2023. Clinical data including demographics information, clinical history, cytology/HPV results, and HRA records were analyzed. Results: : Among the 304 patients, 21.7% were diagnosed with AIN1, 10.2% with AIN2/3, and 1 case with anal cancer. The median age was 42 (IQR: 33-52 years), and the majority (74.7%) were asymptomatic. Individuals with concurrent lower genital tract diseases showed a significantly higher AIN2/3 incidence compared to those without such conditions (14.8% vs. 4.6%, P<0.001), with the highest rate observed in those with concomitant vulvar lesions (17.9%). Anal cytology displayed a sensitivity of 71.0% for detecting AIN2/3. The positive HPV rate was 87.3%, with HPV16 being the most prevalent. HRA demonstrated notable sensitivity and specificity for AIN2/3 diagnosis (94.1% and 89.3% for perianal region, 81.0% and 90.4% for anal canal, respectively). Conclusion: Screening for AIN is crucial in women with lower genital tract disease related to HPV, particularly those with VIN.