Although rare, anal cancer is becoming more prevalent in the United States and many other developing countries. The condition develops in the tissues of the anus, which is a short tube that connects the lower part of the large intestine, known as the rectum, to the outside of the body. The anus allows the controlled disposal of body waste during bowel movements. Like cervical cancer , the principal cause of anal cancer is human papillomavirus HPV , a common virus that causes changes in the skin. Anal HPV infection is most commonly acquired through anal intercourse, but it can also be acquired from other genital areas that are infected, particularly from the vulva in women, or from the penis in men.
The aim of this study was to systematically review the findings of publications addressing the epidemiology of anal HPV infection, anal intraepithelial neoplasia and anal cancer in women. We conducted a systematic review among publications published from January 1, to September 30, in order to limit to publications from the combined antiretroviral therapy cART era. Publications were included in the review if they addressed any of the following outcomes: 1 prevalence, incidence, or clearance of anal HPV infection, 2 prevalence of anal cytological or histological neoplastic abnormalities, or 3 incidence or risk of anal cancer. Thirty-seven publications addressing anal HPV infection and anal cytology remained after applying selection criteria, and 23 anal cancer publications met the selection criteria.
Human papillomavirus HPV , the primary cause of cervical cancer, is also associated with the development of anal cancer. Relatively little is known about the epidemiology of anal HPV infection among healthy females and its relationship to cervical infection. We sought to characterize anal HPV infection in a cohort of adult women in Hawaii. Concurrent anal and cervical HPV infection was most prevalent among the youngest women and steadily decreased through age 50 years.
Anal cancer typically develops over a period of years, beginning with a precancerous condition called anal dysplasia. Anal dysplasia occurs when clusters of abnormal cells form lesions in the mucosa lining of the anal canal between the anus and the rectum. The lesions typically form inside the anal canal or just outside the anal opening. Although there are over different types of the human papillomavirus HPV , anal dysplasia is usually caused by certain strains of HPV which can be transmitted sexually.