Anal cancer rates are rising among people living with HIV. The goal of the ANCHOR study is to find the best way to prevent anal cancer among HIV positive men and women. During a screening visit, you will be screened for pre-cancerous anal lesions. If lesions are found, you will be enrolled and randomized to either have the lesions treated or monitored every six months. Both groups will be followed for a minimum of five years. You will be compensated $100 for the screening visit.