According to a study published in Clinical Infectious Diseases, Pap smears may not be an accurate predictor of high-grade precancerous anal lesions that can lead to the development of anal cancer, reports AIDSmap.com. Recently there has been discussion about the value of offering Pap smears to gay men who have anal human papillomavirus infection. Several studies also have indicated not only that HIV-positive men are at an increased risk of anal cancer but that highly active antiretroviral therapy does not appear to reduce the risk. Investigators from Boston used the results from high-resolution anoscopy from 153 gay men attending an anal dysplasia clinic. Out of the 153 men, 65% were HIV-positive and the remaining 35% were HIV-negative. The results indicated that Pap cytology tests were not an accurate predictor of high-grade precancerous anal lesions; one third of the Pap smears categorized by cytology as "low-grade" were in fact found to be "high-grade."
The study authors noted their data "independently confirms a substantial incidence of histologically proven high-grade anal dysplasia in [gay men] who present with minimally abnormal anal Pap smear findings," and they concluded that "abnormal anal cytological findings of any grade should suggest the possibility of high-grade histological findings."