Anal Canal and Perianal Tumors

Anal Canal and Perianal Tumors

The anus is the name for the muscular opening at the very end of the large bowel.

It is controlled by a ring of muscle called a sphincter that opens and closes to control bowel movements. The area that connects the anus to the rectum is called the anal canal and is around 3-4cm (1-1�in) long.

Cancer of the anus is rare. Around 930 people are diagnosed with anal cancer each year in the UK.

The most common type of anal cancer is squamous cell carcinoma. Other rarer types are basal cell carcinoma, adenocarcinoma and melanoma. This information is about squamous cell carcinoma.

Anal cancer is slightly more common in women than men. There are a number of factors that can increase your risk of developing anal cancer. These include:

Human papilloma virus (HPV)

Anal cancer is more likely to develop in people who have had a viral infection called the human papilloma virus (HPV). The risk of having HPV increases with the number of sexual partners you have.

Sexual activity

People who have anal intercourse are more likely to develop anal cancer. This may be because they are more likely to have anal HPV.

Lowered immunity

The immune system is part of the body's defence against infections and illnesses like cancer.

Anal cancer is more common in people who have a lowered immunity, such as people taking medicines to suppress their immune system after an organ transplant or people with conditions such as HIV.

Smoking

Smoking tobacco increases the risk of developing anal cancer.

However, many people who get anal cancer will not have these risk factors and the cause remains unknown.

The most common symptoms of anal cancer include:

bleeding from the anus
pain, discomfort and itching around the anus
small lumps around the anus, which may be confused with piles (hemorrhoids)
difficulty controlling your bowels (fecal incontinence)
discharge of a jelly-like substance from the anus (mucus)
Ulcers around the anus that can spread to the skin of the buttocks.

The National Institute for Health and Clinical Excellence (NICE) recommends that people with an anal cancer are treated by a specialist team. These teams aren't available in all hospitals, so you may have to travel to another hospital for your treatment. The main type of treatment for anal cancer is a combination of radiotherapy and chemotherapy. The two treatments may be given at the same time (chemoradiation) or in sequence, one treatment following the other. Combined treatment is usually very successful. If radiotherapy and chemotherapy are given at the same time, the side effects can be more severe.

Surgery may be used to treat small anal tumours or be used in combination with chemotherapy or radiotherapy for advanced anal cancer.

Consent

Before you have any treatment, your doctor will give you full information about what it involves and explain its aims to you. They will usually ask you to sign a form saying that you give permission (consent) for the hospital staff to give you the treatment. No medical treatment can be given without your consent.

Surgery

Surgery may be used for small tumors. It can also be used if your initial treatment does not completely get rid of the cancer, or if there are signs that your cancer has returned. There are two main types of surgery: local resection and abdominoperineal resection.

Local resection

This may be used for small tumors on the outside of the anus. This operation only removes the area of the anus containing the cancer cells. The anal sphincter is not usually affected, and so how their bowel works remains the same for most people.

Abdominoperineal resection

This is the removal of the anus and rectum. This operation requires a permanent colostomy, which involves diverting the open end of the bowel on to the surface of the abdomen to allow faces to be passed out of the body into a colostomy bag. The opening on the abdominal wall is known as a stoma.

Although the idea of a colostomy is often frightening and distressing at first, most people find that they adapt over time and can return to their normal activities.

You can get support and advice from the stoma nurse in your hospital. Our cancer support specialists can send you information about having a colostomy.

A stoma is an opening, either natural or surgically created, which connects a portion of the body cavity to the outside environment. Surgical procedures in which stomata are created are ended in the suffix -ostomy and begin with a prefix denoting the organ or area being operated on.

In anatomy, a natural stoma is any opening in the body, such as the mouth. Any hollow organ can be manipulated into an artificial stoma as necessary. This includes the esophagus, stomach, duodenum, ileum, colon, pleural cavity, ureters, urinary bladder, and kidney pelvis.

One well-known form of an artificial stoma is a colostomy, which is a surgically created opening in the large intestine that allows the removal of feces out of the body, bypassing the rectum, to drain into a pouch or other collection device.