Description of Anal Cancer

Anal cancer, an uncommon cancer, is a disease in which cancer (malignant) cells are found in the anus. The anus is the opening at the end of the rectum (the end part of the large intestine) through which body waste passes. Cancer in the outer part of the anus is more likely to occur in men; cancer of the inner part of the rectum (anal canal) is more likely to occur in women. If your anus is often red, swollen, and sore, you have a greater chance of getting anal cancer. Tumors found in the area of skin with hair on it just outside the anus are skin tumors, not anal cancer.

Like most cancers, anal cancer is best treated when it is found (diagnosed) early. You should see your doctor if you have one or more of the following symptoms: bleeding from the rectum (even a small amount), pain or pressure in the area around the anus, itching or discharge from the anus, or a lump near the anus.

If you have signs of cancer, your doctor will usually examine the outside part of the anus and give you a rectal examination. In a rectal examination, your doctor, wearing thin gloves, puts a greased finger into the rectum and gently feels for lumps. Your doctor may also check any material on the glove to see if there is blood in it. If you feel pain when touched in the anal area, your doctor may give you medicine to put you to sleep (general anesthesia) in order to continue the examination. Your doctor may cut out a small piece of tissue and look at it under a microscope to see if there are any cancer cells. This procedure is called a biopsy.

Your prognosis (chance of recovery) and choice of treatment depend on the stage of your cancer (whether it is just in the anus or has spread to other places in the body) and your general state of health.

Stages Of Anal Cancer

Once anal cancer is found (diagnosed), more tests will be done to find out if cancer cells have spread to other parts of the body. This testing is called staging. To plan treatment, your doctor needs to know the stage of your disease. The following stages are used for anal cancer.

Stage 0 Or Carcinoma In Situ Stage 0 anal cancer is very early cancer. The cancer is found only in the top layer of anal tissue.

Stage I The cancer has spread beyond the top layer of anal tissue and is smaller than 2 centimeters (less than 1 inch).

Stage II Cancer has spread beyond the top layer of anal tissue and is larger than 2 centimeters (about 1 inch), but it has not spread to nearby organs or lymph nodes. (Lymph nodes are small, bean-shaped structures found throughout the body. They produce and store infection-fighting cells.)

-- Stage IIIA -- Cancer has spread to the lymph nodes around the rectum or to nearby organs such as the vagina or bladder.

Stage IIIB Cancer has spread to the lymph nodes in the middle of the abdomen or in the groin, or the cancer has spread to both nearby organs and the lymph nodes around the rectum.

Stage IV Cancer has spread to distant lymph nodes within the abdomen or to organs in other parts of the body.

Recurrent Recurrent disease means that the cancer has come back (recurred) after it has been treated. It may come back in the anus or in another part of the body.

How Anal Cancer Is Treated

There are treatments for all patients with anal cancer. Three kinds of treatment are used: surgery (taking out the cancer in an operation) radiation therapy (using high-dose x-rays or other high-energy rays to kill cancer cells) chemotherapy (using drugs to kill cancer cells).

Surgery is a common way to diagnose and treat anal cancer. Your doctor may take out the cancer using one of the following methods:

Local resection is an operation that takes out only the cancer. Often the ring of muscle around the anus that opens and closes it (the sphincter muscle) can be saved during surgery so that you will be able to pass your body wastes as before.

Abdominoperineal resection is an operation in which the doctor removes the anus and the lower part of the rectum by cutting into the abdomen and the perineum, which is the space between the anus and the scrotum (in men) or the anus and the vulva (in women). Your doctor will then make an opening (stoma) on the outside of the body for waste to pass out of the body. This opening is called a colostomy. Although this operation was once commonly used for anal cancer, it is not used as much today because radiation therapy with or without chemotherapy is an equally effective treatment option but does not require a colostomy. If you have a colostomy, you will need to wear a special bag to collect body wastes. This bag, which sticks to the skin around the stoma with a special glue, can be thrown away after it is used. This bag does not show under clothing, and most people take care of these bags themselves. Lymph nodes may also be taken out at the same time or in a separate operation (lymph node dissection).

Radiation therapy uses x-rays or other high-energy rays to kill cancer cells and shrink tumors. Radiation may come from a machine outside the body (external radiation therapy) or from putting materials that produce radiation (radioisotopes) through thin plastic tubes in the area where the cancer cells are found (internal radiation therapy). Radiation can be used alone or in addition to other treatments.

Chemotherapy uses drugs to kill cancer cells. Chemotherapy may be taken by pill, or it may be put into the body by a needle in a vein or muscle. Chemotherapy is called a systemic treatment because the drugs enter the bloodstream, travel through the body, and can kill cancer cells throughout the body. Some chemotherapy drugs can also make cancer cells more sensitive to radiation therapy. Radiation therapy and chemotherapy can be used together to shrink tumors and make an abdominoperineal resection unnecessary. When only limited surgery is required, the sphincter muscle can often be saved.

Treatment By Stage

Treatments for anal cancer depend on the type of disease, stage of disease, your age, and your general health.

You may receive treatment that is considered standard based on its effectiveness in a number of patients in past studies, or you may choose to go into a clinical trial. Not all patients are cured with standard therapy, and some standard treatments may have more side effects than are desired. For these reasons, clinical trials are designed to find better ways to treat cancer patients and are based on the most up-to-date information. Clinical trials are going on in most parts of the country for most stages of anal cancer. If you wish to know more about clinical trials, call the Cancer Information Service at 1-800-4-CANCER (1-800-422-6237); TTY at 1-800-332-8615.

STAGE 0 ANAL CANCER

Your treatment will probably be local resection.

STAGE I ANAL CANCER

Your treatment may be one of the following: 1. Local resection (for some small tumors). 2. External radiation therapy with chemotherapy. Some patients may also receive internal radiation therapy. 3. If cancer cells remain following therapy, you may need surgery of the anal canal to remove the cancer.

STAGE II ANAL CANCER

Your treatment may be one of the following: 1. Local resection (for small tumors). 2. External radiation therapy with chemotherapy. Some patients may also receive internal radiation therapy. 3. If cancer cells remain following therapy, you may need surgery of the anal canal to remove the cancer.

STAGE IIIA ANAL CANCER

Your treatment may be one of the following: 1. Radiation therapy with chemotherapy. 2. Surgery. Depending on how much cancer remains following chemotherapy and radiation, local resection or surgery to remove cancer in the anal canal may be done. 3. Clinical trials of surgery (resection) followed by external radiation therapy. 4. Clinical trials of surgery followed by chemotherapy if chemotherapy has not been used prior to surgery.

STAGE IIIB ANAL CANCER

Your treatment will probably be radiation therapy and chemotherapy followed by surgery. Depending on how much cancer remains following chemotherapy and radiation, local resection or surgery to remove the anus and the lower part of the rectum (abdominoperineal resection) may be done. During surgery, the lymph nodes in the groin may be removed (lymph node dissection).

STAGE IV ANAL CANCER

Your treatment may be one of the following: 1. Surgery to relieve symptoms. 2. Radiation therapy to relieve symptoms. 3. Chemotherapy and radiation therapy to relieve symptoms. 4. Clinical trials.

RECURRENT ANAL CANCER

Your choice of treatment will be based on what treatment you received when the cancer was first treated. If you were treated with surgery, you may receive radiation therapy if the cancer recurs. If you were treated with radiation, you may have surgery if the cancer recurs. Clinical trials are studying new chemotherapy drugs with or without radiation therapy