Human papillomavirus, smoking, and sexual practices in the etiology of anal cancer

The incidence of anal cancer has increased among both men (160%) and women (78%) from 1973 to 2000 in the U.S. The authors conducted a population-based case-control study of anal cancer to examine factors that may account for this increase.

Men (n = 119 patients) and women (n = 187 patients) who were diagnosed with anal cancer between 1986 and 1998 in the Seattle area were ascertained through the local Surveillance, Epidemiology, and End Results registry. Control participants (n = 1700) were ascertained through random-digit telephone dialing. Participants were interviewed in person and provided blood samples. Archival tumor tissue was tested for human papilloma virus (HPV) DNA, and serum samples were tested for HPV type 16 (HPV-16).