High prevalence of anal squamous intraepithelial lesions and squamous cellcarcinoma in men who have sex with men as seen in a surgical practice

Anal high-grade squamous intraepithelial lesions are probable invasive anal squamous-cell cancer precursors, and although unproved, treatment of high- grade squamous intraepithelial lesions may prevent progression to anal squa mous-cell cancer. Men who have sex with men are often treated for benign an orectal disorders without consideration given to the possibility of concurr ent high-grade squamous intraepithelial lesions or anal squamous-cell cance r. We determined the prevalence of anal high-grade squamous intraepithelial lesions and anal squamous-cell cancer in an urban surgical practice of men who have sex with men referred for treatment of anal condyloma and other b enign noncondylomatous anal disorders. METHODS: One hundred thirty-one HIV- positive and 69 HIV-negative men who have sex with men referred for surgica l treatment of presumed benign anorectal disease were evaluated by anal cyt ology, high-resolution anoscopy, and biopsy. Anal cytology. and histology w ere reported with a modified Bethesda classification. RESULTS: One hundred fifty-seven patients (79 percent) were referred for condyloma, 4 (2 percent ) for anal squamous intraepithelial lesions (anal high-grade squamous intra epithelial lesions) diagnosed by primary care providers, and 39 (19 percent ) for other benign anorectal disorders. One hundred forty-three patients (9 3 percent) had abnormal anal cytology, with 107 (54 percent) having high-gr ade squamous intraepithelial lesions on cytology. Biopsy results revealed 1 20 patients (60.0 percent) with high-grade squamous intraepithelial lesions and 5 patients (3 percent) with invasive squamous-cell carcinoma. Four of five men with anal squamous-cell cancer were HIV positive. Fourteen men (36 percent) who have sex with men referred for noncondylomatous benign anal d isorders had high-grade squamous intraepithelial lesions, and three (8 perc ent) had anal squamous-cell cancer. High-grade squamous intraepithelial les ions and anal squamous-cell cancer were seen most often at the squamocolumn ar junction. CONCLUSIONS: Men who have sex with men referred for treatment of either condyloma or noncondylomatous benign anorectal disease had a high prevalence of anal high-grade squamous intraepithelial lesions and anal sq uamous-cell cancer. All men who have sex with men referred for treatment of benign anorectal disease should have high-resolution anoscopy and aggressi ve biopsy of all abnormal areas. Treatment of external lesions alone could miss high-grade squamous intraepithelial lesions or anal squamous-cell canc er.