High-grade anal intraepithelial neoplasia (HGAIN) is a presumed precursor of anal squamous cell carcinoma (SCC). Risk factors for the development of HGAIN are less clear. Therefore, the aim of this study was to identify risk factors for HGAIN in women undergoing high-resolution anoscopy (HRA).
Women referred for evaluation of perianal HPV infection, abnormal anal cytology or high risk HPV DNA testing that underwent HRA at our institution were identified from 2013 to 2015. Patient demographics, presence of immunocompromised state (HIV, autoimmune disorder, other malignancy), sexual history (coitarche, number of partners, anal intercourse), presence of vulvar intraepithelial neoplasia (VIN) or cervical intraepithelial neoplasia (CIN) were abstracted from chart review. Descriptive statistics and univariate analyses were used to compare women with and without HGAIN (chi-square test for categorical variables, 2-sample t test for continuous variables).
There were 55 women identified during the study period, of which 22 were found to have HGAIN. Women with HGAIN had a significantly greater smoking history (mean pack-years: 23.8 vs 7.6, p=0.003) and were more likely to have VIN 2-3 (p=0.032). History of immunosuppressive state was marginally non significant (p=0.051). None of the other variables including age at coitarche, number of sexual partners and history of anal intercourse were significantly different between groups.
We found that heavy smoking and high grade VIN were associated with presence of HGAIN. Further study in a larger cohort to confirm our findings is needed to identify high risk women who should be screened for HGAIN using HRA.