Though it is infrequent at a rate of 1 per 100 000, anal SCC is on the rise in the general population. It occurs at significantly higher rates in HIV-positive MSM with an estimated rate of 60 to 160 per 100 000. Rates of anal cancer among HIV infected MSM are comparable to rates of cervical cancer in women prior to the adoption of routine screening for cervical dysplasia. Anal cancer shares many similarities with cervical cancer.