Anal Carcinoma Surveillance Counterpoint: USA

Anal cancer accounts for 4 % of all lower gastrointestinal tract malignancies in the United States [1]. The incidence of anal cancer appears to be on the rise, with increases in incidence rates of 2.6 % per year reported between 1992 and 2000 [2]. Over 5,000 new cases of anal cancer are diagnosed in the U.S. annually [3]. The overall 5-year survival rate is 66.5 % [4]. This varies by stage at diagnosis (82 % for local disease; 59 % for regional disease and 19 % for distant disease) [3]. The vast majority (65–85 %) of anal malignancies are squamous cell carcinomas, which include various histological subtypes such as cloacogenic, basaloid, and transitional cell cancers [2]. Cancers of the anus have been categorized as those arising in the anal canal, or intraanal, and those arising at the anal margin, or perianal region [5].