An estimated 5290 new cases (2100 men and 3190 women) of anal cancer (involving the anus, anal canal, or anorectum) will occur in the United States in 2009, accounting for approximately 1.9% of digestive system cancers, and an estimated 710 deaths due to anal cancer. Although considered to be a rare type of cancer, the incidence rate of invasive anal carcinoma in the United States increased by approximately 1.6-fold for men and 1.5-fold for women from 1973-1979 to 1994-2000 (see Risk Factors, facing page).
This manuscript summarizes the NCCN Clinical Practice Guidelines in Oncology for managing squamous cell anal carcinoma, which represents the most common histologic form of the disease. Other types of cancers occurring in the anal region are addressed in other NCCN guidelines (i.e., anal adenocarcinoma and anal melanoma are managed according to the NCCN Clinical Practice Guidelines in Oncology on Rectal Cancer and Melanoma, respectively). Except where noted, the recommendations in these guidelines are classified as category 2A, meaning that uniform NCCN consensus was present among the panel based on lower-level evidence that the recommendation is appropriate. The panel unanimously endorses patient participation in a clinical trial over standard or accepted therapy.
Anal carcinoma has been associated with human papilloma virus (HPV) infection (anal-genital warts); history of receptive anal intercourse or sexually transmitted disease; history of cervical, vulvar, or vaginal cancer; immunosuppression after solid organ transplantation or HIV infection; and smoking. Currently, the association between anal carcinoma and persistent infection with a high-risk form...