Two muscles shaped like rings, called the sphincter muscles, open and close the anal orifice to allow the fecal matter to be eliminated from the body. The anal channel, the anus segment found between the rectum and the anal orifice, has a length of some 1.5 inches. The tegument around the anus is called the perianal area. Tumors in this area can be skin cancers, not anal cancer.
The presence of a human papilloma virus (HPV) infection is a risk factor in the occurrence of anal cancer. Risk factors for the occurrence of anal cancer are: age above 50, the presence of a human papilloma virus infection, multiple sexual partners, the practice of anal sex, the frequent presence of anal redness, inflammation and itchiness, the presence of anal fistulas (abnormal connection between two cavities), smoking.
Possible signs of anal cancer include bleeding from the anus or from the rectum, or a bump near the anus. There are also other reasons for such symptoms, not just anal cancer. You need to go to a doctor if you see one of the following signs: bleeding from the anus or from the rectum, pain or pressure in the perianal area, itchiness or secretions from the anus, a bump near the anus, changes in the stool (diarrhea or constipation. Tests that examine the rectum and anus are used to find and diagnose anal cancer.
The tests that can be used in these cases include:
- objective examination and the patient’s family history: a general physical examination searching for any signs of illness, such as bumps or other unusual aspects; the diseases contracted before and the treatment followed; a bit of information about the lifestyle and eating habits of the patient
- rectal digital examination: this is an examination of the anus or rectum; the doctor or nurse, using surgical gloves, introduces a lubricated finger in the lower side of the rectum, searching for potential bumps or peculiarities
- anoscopy: this is an examination of the anus and of the rectum in the lower side using a short tube, with a led at the end, called an anoscope
- proctoscopy: this is an examination of the rectum using a short tube, with a led at the end, called a proctoscope
- endoanal and endorectal ultrasonic scan: this is a procedure in which an ultrasound transducer is introduced in the anus or rectum, the ultrasound hits the internal tissue ot the organs and produces various echoes depending on consistency, thus achieving a sonogram
- biopsy: this procedure consists of collecting cells or tissue, which is later studied under a microscope by a pathologist searching for signs of cancer;