Pathophysiology of Anal Cancer.

The pathophysiology of the development of anal cancer is thought to be linked to chronic inflammation, a possible consequence of infections with human papillomavirus (HPV) or HIV, or inflammation from inflammatory bowel disease. Anal HPV-induced carcinogenesis bears similarities to its cervical counterpart via viral integration into the host genome and the development of precursor lesions termed anal intraepithelial neoplasia. HPV-16 and -18 are the most common HPV genotypes associated with anal cancer. Other risk factors for the development of anal cancer include chronic immunosuppression, sexual activity and sexually transmitted diseases, female gender, history of anogenital dysplasia, and smoking.