The anal canal is a short tube surrounded by muscle at the end of your rectum. The rectum is the bottom section of your colon large intestine. When you have a bowel movement, stool leaves your body from the rectum through the anal canal. As the cancer grows, it may stay in nearby tissues or spread to other parts of the body, a process called metastasis.
A risk factor is something that increases the risk of developing cancer. It could be a behaviour, substance or condition. Most cancers are the result of many risk factors. Human papillomavirus HPV infection is the most important risk factor for anal cancer. The risk of developing anal cancer increases with age.
A risk factor is anything that affects your chance of getting a disease such as cancer. Different cancers have different risk factors. Some risk factors, like smoking or diet, can be changed.
To examine the incidence and risk factors for anal cancer in a multicenter cohort of HIV-positive and negative men who have sex with men followed between and MACS. Prospective analysis using Poisson regression and Cox proportional hazard models, and a nested case-control study using conditional logistic regression. There were 28 cases of anal cancer among the 6, men who were evaluated. HIV-positive men had increased risk of anal cancer.