Anal cancer occurs in the anus, the end of the gastrointestinal tract. Anal cancer is very different from colorectal cancer, which is much more common. Its causes, risk factors, clinical progression, staging and treatment, are all very different from colorectal cancer. Anal cancer, though rare, is a lump created by the abnormal and uncontrolled growth of cells in the anus.
The most common symptom associated with anal cancer is bleeding. Itching at the anal opening may also be a symptom, although many people, initially, attribute such bleeding and itching to haemorrhoids. This can delay the diagnosis of anal cancer. Other signs and symptoms of anal cancer may include:
Pressure in the anal area
Unusual discharges from the anus
Lump near the anus
Change in bowel habits
Factors that are known to affect the development of anal cancer are the following:
Age of 50 years or above
Human Papillomavirus (HPV) infection
Multiple sexual partners
Having receptive anal intercourse (anal sex)
Frequent anal redness, swelling, and soreness
Having anal fistulas (abnormal openings)
Anal cancer can be detected using the following tests and procedures:
Physical Examination and History
An exam of the body to check general signs of health, including checking for signs of disease, such as lumps or anything else that seems unusual, is more important than most people realize. A history of the patient's health habits and past illnesses, and treatments, is also taken.
Digital Rectal Examination (DRE)
DRE involves examination of the anus and rectum. A lubricated, gloved finger is inserted into the lower part of the rectum to feel for lumps or unusual masses.
There are different ways to treat anal cancer, depending upon which stage it is in, if the patient has HIV or if the cancer is a recurrence.
Radiation therapy is a cancer treatment that uses high-energy X-rays or other types of radiation to kill cancer cells. There are two types of radiation therapy. External radiation therapy uses a machine outside the body to send radiation toward the cancer. Internal radiation therapy uses a radioactive substance sealed in needles, seeds, wires, or catheters that are led directly into or near the cancer. The way radiation therapy is given depends on the type and stage of cancer.
Chemotherapy is a cancer treatment that uses drugs to stop the growth of cancer cells, either by killing them or by stopping them from dividing. When chemotherapy is taken orally or injected into a vein or muscle, the drugs enter the bloodstream and can reach cancer cells throughout the body (systemic chemotherapy). When chemotherapy is placed directly into the cerebrospinal fluid, an organ, or a body cavity such as the abdomen, the drugs mainly affect cancer cells in those areas (regional chemotherapy). The mode of administration of chemotherapy depends on the type and the stage of the cancer being treated.
Local resection - A surgical procedure in which the tumour is cut from the anus along with some of the healthy tissue around it. Local resection may be used if the cancer is small and has not spread. This procedure may save the sphincter muscles so the patient can still control bowel movements. Tumours that form in the lower part of the anus can often be removed with local resection.
Abdominoperineal resection - A surgical procedure in which the anus, the rectum, and part of the sigmoid colon are removed through an incision made in the abdomen. The doctor sews the end of the intestine to an opening, called a stoma, made in the surface of the abdomen so body waste can be collected in a disposable bag outside the body. This is called a colostomy. Lymph nodes that contain cancer may also be removed during this operation.