Comparison of anal pre-cancer screening strategies among men who have sex with men.

ABSTRACT

PURPOSE: Comparison of anal pre-cancer screening strategies in men who have sex with men (MSM). METHODS: MSM in the Multicenter AIDS Cohort Study underwent repeated anal cytology (aCyt), oncogenic human papillomavirus (oncHPV) testing. A subset received High-Resolution Anoscopy (HRA). We evaluated three screening strategies for their ability to predict anal histological High-Grade Squamous Intraepithelial lesion (HSIL) single aCyt, sequential aCyt, and oncHPV co-testing. Multivariable logistic regression models evaluated risk of HSIL among participants undergoing HRA within 5 years of screening. Sensitivity and specificity were estimated among participants with HRA, and results corrected for verification bias using weighted generalized estimating equations. RESULTS: There were 1426 MSM with aCyt screening (48% people with HIV [PWH]) and 428 that underwent HRA. Median age was 57 years, 14% of PWH had CD4< 350 cells/mm3. HSIL probability was higher in MSM with one (39%, p < 0.01) or two abnormal aCyt results (46%, p < 0.01), versus those with normal aCyt (23-24%). Among men with abnormal aCyt, men with oncHPV+ had significantly higher risk than those who were oncHPV- (47% vs. 16%, p < 0.01). Specificity was modest with single aCyt+ (50%) but increased with sequential aCyt+ (79%) or oncHPV+ (67%). Sensitivity was high with single oncHPV+ (88%), moderate with single aCyt+ (66%) and oncHPV+ co-testing (61%), and low with sequential aCyt+ (39%). After correcting for potential verification bias, specificity increased and sensitivity decreased, but inferences were similar. CONCLUSION: None of the screening strategies evaluated had both sufficient specificity and sensitivity to warrant routine widespread use.