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

Comparison of anal pre-cancer screening strategies in men who have sex with men (MSM).

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.

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.

None of the screening strategies evaluated had both sufficient specificity and sensitivity to warrant routine widespread use.