Cancer of the anus, not to be confused with rectal cancer, is a cancer that is located in the anal canal. It represents 1-2% of colorectal tumors. It usually appears after the age of 60. It is generally more common in women for in men, the incidence appears to be higher among homosexuals affected by human immunodeficiency virus (HIV). It develops as a result of an infection with the "HPV" virus, transmitted by direct contact, usually during sexual intercourse. Smoking and AIDS are also risk factors.
Symptoms of anal cancer are:
- rectal bleeding, found at the anal orifice or on toilet paper;
- the presence of a lump;
- pain during defecation;
- bowel movement disorders.
Anal cancer can be detected by rectal examination or anoscopy, examination of the anus using an endoscope to check the extent of the lesion. A biopsy sample from the tumor lesion is taken and will confirm the diagnosis of cancer. If the diagnosis is proven, other tests such as a CT scan or MRI may be necessary to search for the spreading of tumor to other glands or organs.
Radiotherapy and chemotherapy are often used, depending on the size of the tumor and its location. Radiotherapy reduces the risk of local recurrence, facilitates the removal of the tumor via surgery if needed and relieves symptoms. In addition, chemotherapy, used before or after surgery, reduces the risk of recurrence more extensively.