Anal cancer cause

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.

Anal cancer occurs in the anus, which is at the end of the gastrointestinal tract. It is different from and less common than colorectal cancer, which is cancer of the colon or rectum. Anal cancer is rare, but the number of new cases is rising. Of these, 5, will affect females, and 2, will affect males.

If you have symptoms of cancer contact your doctor. Read our information about coronavirus and cancer. Your risk of developing anal cancer depends on many things, including age and lifestyle factors. Having HPV is the biggest risk factor for anal cancer. Most of us have HPV at some point during our life.

Researchers continue to investigate the causes of anal cancer. Known risk factors that have been identified include chronic infection with high-risk types of human papillomavirus HPV , gender and age. HPV, a collection of more than viruses spread primarily by contact during vaginal, oral or anal sexual activity, is responsible for the majority of anal cancers. HPV may be asymptomatic for years, and persistent HPV infections may cause cell changes that, left untreated, may become cancer. The HPV vaccine provides protection against numerous strains of the virus, including subtypes 16 and 18, which are responsible for most HPV-related cancers.