Anal cancer screening in men who have sex with men.
OBJECTIVE
To determine whether current evidence and expert opinion support the routine use of anal cytology and high-resolution anoscopy in men who have sex with men.


RESULTS
Most recently published guidelines do not recommend routine anal cytology, but anal cancer is undoubtedly a serious and growing problem for HIV-positive patients. Two recent cohort studies have provided data that suggest that the precursor lesion (high-grade squamous intraepithelial lesion) might not be more prevalent in patients on highly active antiretroviral therapy than in historical pre-highly active antiretroviral therapy cohorts or in HIV-negative men who have sex with men. If substantiated by further studies, this would make it easier to focus intervention with high-resolution anoscopy on a smaller group of patients. This would be helpful because high-resolution anoscopy remains a resource that is both costly and difficult to access in most countries. The sensitivity and specificity of anal cytology is poor and adjuncts to cytology such as p16(ink4a) staining and human papillomavirus viral loads might be utilized to further reduce the number of patients requiring high-resolution anoscopy. Despite the burden of high-grade squamous intraepithelial lesion in HIV negative men who have sex with men, anal cancer remains uncommon in this group.


CONCLUSIONS
Although routine anal cytology is not advisable for men who have sex with men at present, be they HIV positive or negative, clinicians should be regularly performing digital rectal examination in those at high risk of anal cancer, both to facilitate early detection of anal cancer and in the interests of health promotion.
Fox
Paul
P
Chelsea & Westminster Hospital, St. Stephen's Centre, 369 Fulham Road, London SW109NH, UK. Paul.Fox@eht.nhs.uk