Correlation of anal cytology with follow-up histology and Human Papillomavirus genotyping: A 10-year experience from an academic medical center

Evaluating the performance of anal cytology and high-risk HPV genotyping for detecting anal HSIL in a clinic-based sample of people living with and without HIV in Puerto Rico

BACKGROUND

Given the disproportionately elevated anal cancer risk in high-risk populations, it is important to assess the performance of commonly used anal cancer screening tools to improve the effectiveness of detection and treatment methods. This study evaluates 1) the concordance between anal cytology and histology results and 2) the performance of cytology and high-risk human papillomavirus (HR-HPV) genotyping as screening tools for detecting histologically confirmed anal high-grade squamous intraepithelial lesions (HSIL).

METHODS

Data from the Anal Neoplasia Clinic in Puerto Rico (2014-2021; n = 466) was used. The clinical performance of anal cytology and HR-HPV genotyping to detect HSIL was compared to the gold standard: high-resolution anoscopy-guided biopsy. Sensitivity, specificity, positive predictive value, negative predictive value, and κ coefficients were calculated.

RESULTS

A total of 66.95% of the patients were men, 74.0% were people living with HIV, 76.2% had anal HR-HPV infection, and 40.34% had histologically confirmed anal HSIL. The weighted κ statistic between the tests (cytology and histology) was 0.25 (p < .001). The sensitivity and specificity of cytology alone to detect anal HSIL were 84.3% (95% confidence interval [CI], 78.3%-89.1%) and 36.0% (95% CI, 30.3%-42.0%), respectively. Anal HR-HPV genotyping had higher sensitivity (92.2%; 95% CI, 87.4%-95.6%) and similar specificity (34.8%; 95% CI, 29.2%-40.7%) compared to cytology. The two tests combined (positive results following cytology or HR-HPV test) improved sensitivity to detect anal HSIL (97.9%; 95% CI, 94.8%-99.4%), but specificity was compromised (19.2%; 95% CI, 14.7%-24.4%).

CONCLUSION

Although HR-HPV genotyping improved the detection of anal HSIL, HR-HPV testing had lower specificity than anal cytology alone.

Conventional cytologic diagnosis of human papillomavirus-induced anal intraepithelial neoplasia: The experience of a referral center in Rio de Janeiro, Brazil

BACKGROUND

Screening of anal cancer is rarely available or performed in Brazil. This study analyzes the diagnostic performance of conventional cytology (CC) in the prevention of anal cancer in a coloproctology and gynecology outpatient clinics in a public hospital in Rio de Janeiro, Brazil.

METHODS

From 2005 to 2017, 1066 conventional cytological samples were collected. We analyze the causes of unsatisfactory samples (11.3%) and compare the cytological diagnoses of 83 samples from persons living with HIV and persons not living with HIV and in specific situations, using as the gold standard high-resolution anoscopy or histopathology in cases biopsied within 6 months after cytology.

RESULTS

The sensitivity of cytology with diagnosis of ASC-US for detection of anal intraepithelial neoplasia of any grade was 85%, specificity was 41%, positive and negative predictive values were 64% and 75%, respectively, and positive and negative likelihood ratios were 1.46 and 0.35, respectively.

CONCLUSION

Conventional cytology available in resource-limited settings is a simple, noninvasive, low-cost method that proved feasible for outpatient screening of precursor lesions of the anal canal.