Causes of Anal Cancer

There are some known causes of anal cancer that at least in part contribute to the development of the disease. Like most cancers' causes, these tumors are caused by mutations of the DNA in cells that lead to the ability of the cells to grow uncontrollably into a tumor. There are many things that can cause these mutations including aging, environmental toxins and viruses.

In the case of causes of anal cancer, there are at least a couple known risk factors that contribute to the development of these cancers. Probably one of the most common causes is infection by a virus called human papilloma virus (HPV). There are many different types of papilloma viruses that can infect the skin and other tissues. Some produce no outward symptoms or signs. Some produce warts. Anal warts produced by HPV increase the risk for development of anal cancer. Most notably, a form called HPV-16 is most associated with squamous cell carcinoma of the anus. However, it should be noted that warts are common and most people with warts do not develop cancer. HPV is spread by direct contact. Therefore, most anal warts are sexually transmitted. People with a history of anal warts can have them tested for the presence of the highest risk types of HPV and can get screened regularly to catch early cancer should it develop.

Smoking can also contribute to the development of anal cancer, particularly in people who have other risk factors like anal warts. Older age, as with most cancers, also increase the risk of these cancers.

While these risk factors partially explain the causes of anal cancer, they do not explain the development of the disease in all individuals. In fact, some patients with anal cancer may not have any of these risk factors and the cause of their cancer may be unknown or just assumed to be due to random mutations not associated with HPV or smoking.