State-of-the-Art of High-Resolution Anoscopy as a Tool to Manage Patients at Risk for Anal Cancer

Abstract

Anal cancer is increasing in incidence in urban populations worldwide and particularly in HIV-positive men who have sex with men (MSM). The etiologic relationship of both anal and cervical cancer to human papillomavirus (HPV) is well established. The incidence of cervical cancer has decreased significantly as a result of an effective screening program. Women with abnormal cervical cytology are referred for colposcopy, which is used to identify and eradicate the cervical cancer precursors, cervical high-grade squamous intraepithelial lesions (HSIL). High-resolution anoscopy (HRA) or colposcopy of the anus and perianal area is a powerful tool to find and treat the precursors to anal cancer, anal HSIL. The approach to management and treatment of anal HSIL at the UCSF Anal Dysplasia Clinic using HRA in conjunction with anal cytology and digital rectal examination (DRE) is presented as a means to prevent anal cancer and to facilitate the early diagnosis of anal cancer. Principles of HRA, how to perform HRA, findings during HRA, and the use of HRA in the operating room are described. HRA coupled with DRE is an effective way to manage patients at risk for anal cancer. Several cases are described illustrating the practical application of HRA in managing patients with anal HSIL and diagnosing anal cancer. Increased awareness and, at the very least, performance of regular DRE in patients at risk and training more providers in HRA may help to decrease the incidence of anal cancer in populations at risk.