15. Evaluation of anal cytology versus high-resolution anoscopy (HRA) in the diagnosis of preneoplastic lesions in a multicenter HIV-infected Spanish Cohort (CoRIS-HRA): incorporation of cellular proliferation molecular markers into the algorithm

Background Evaluation of the diagnostic value of anal cytology versus HRA in detecting anal intraepithelial neoplasia (AIN) and the added value of molecular markers in a multicenter cohort of HIV positive MSM (CoRIS-HRA). Methods: Concomitant anal liquid cytology and HRA with biopsy of acetowhite lugol-negative lesions if observed. Concordance was evaluated by the Kappa index. Dual staining for p16INK4a and Ki-67 (CINtec® PLUS, Roche) was done in cytology samples. Taking biopsy as the ‘gold standard’ for AIN diagnosis, the sensitivity and specificity of anal cytology and p16INK4/Ki-67 dual positivity was calculated. Results: Since November 2012, 172 patients were recruited in five Spanish hospitals. In 56 patients, no biopsies were performed as no lesions were observed. In the remaining 116 patients, 142 biopsies were obtained. Among 172 cytologies, 10.5% were inadequate, 27.9% negative, 1.1% ASCUS, 45.3% LSIL and 15.2% HSIL. Histology showed inadequacy in 3.5% of cases, negativity in 25.3%, LG-AIN in 35.2% and HG-AIN in 35.9%. In 116 patients, cytology and biopsy results were available (the highest lesion grade was used if multiple biopsies existed); the strength of agreement was fair (Kappa 0.351; 95% CI 0.232–0.470). Sensitivity and specificity of anal cytology versus HRA guided biopsy was 88.3% and 66.7%, respectively. In 67 cases, results from dual staining for p16INK4a/Ki-67 were available, rendering a sensitivity of 47.3% and a specificity of 66.7% compared with histology results. Conclusions: Although preliminary, our results show that in our setting dual staining for p16INK4a/Ki-67 did not improve the operational characteristics of anal liquid cytology.