71935 - Endoscopic screening for anal high grade squamous intraepithelial dysplasia in HIV-positive men who have sex with men

Introduction Anal Squamous Intraepithelial Lesions (ASIL) are precursors to anal cancer. The highest risk is found in HIV-positive men having sex with men (MSM). The aim of the study is to evaluate flexible endoscopy as a screening method for ASIL. Method 304 HIV-positive MSM were included. At inclusion, anal samples were taken for HPV-PCR, cytology, chlamydia and gonorrhea. Previous chlamydia/gonorrhea infections, smoking habits, years with HIV, nadir CD4 count, initiation of antiretroviral therapy, previous ASIL/condyloma and symptoms from the anal canal were collected. A diagnostic endoscopy was performed using underwater technique. Number of lesions and morphology were documented. Detected lesions were removed with diathermy-snare after submucosal injection of lidocaine in un-anesthetized patients. Result Presently, we have performed anal endoscopy in 283 individuals. Macroscopic lesions were found in 230 cases (81%). Endoscopic resection in 189 cases with findings of one case (0,5 %) of squamous cell carcinoma, surgical R0 resection, no oncologic treatment necessary. 74 patients (39 %) with HSIL, 47 (25%) with LSIL, 7 (4 %) indeterminate for LSIL/HSIL and 60 (32 %) without dysplasia. Swabs for cytology had a sensitivity for SCC/HSIL of 12%, specificity of 50% and for HPV-PCR a sensitivity for SCC/HSIL of 61%, specificity of 42%.Possible correlation with nadir CD4, duration of HIV infections, tobacco use, and number of previous anal chlamydia/gonorrhea remain to be analyzed. Discussion Preliminary data from a still ongoing study indicate that flexible endoscopy is useful for screening high-risk individuals and for resection of dysplastic lesions. Anal cytology did not meet our expectations but HPV-PCR showed a more promising result.