Anal Cancer

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Treating Anal Cancer TOPICS

Treatment of anal cancer by stage

The type of treatment your cancer care team will recommend depends on the type of cancer and how far it has spread. This section sums up the options for anal cancer treatment according to the stage of disease. Anal tumors affecting the anal margin or the perianal skin (and not the anal canal) are considered to be skin cancers. Information about their treatment can be found in our document, Skin Cancer: Basal and Squamous Cell. These cancers are not treated in the same way as anal canal cancers.

Stage 0

Stage 0 tumors can often be completely removed by surgery (local resection). Radiation therapy and chemotherapy (chemo) are rarely needed.

Stages I and II

Local resection can be used to remove small tumors (usually less than 1 centimeter or ½ inch) that do not involve the sphincter. In some cases, resection may be followed with chemo and radiation therapy.

The standard treatment for anal cancers that can't be removed without harming the anal sphincter is radiation therapy combined with chemo (chemoradiation). Chemoradiation is as good as (or even better than) removing the cancer as part of a radical surgery called abdominoperineal resection (APR). APR involves removing the anus and rectum and requires a colostomy to be formed. Chemoradiation can work just as well and avoid the need for a colostomy.

Using radiation therapy combined with chemo has been shown to be better than using radiation alone in the treatment of anal cancer. The 2 treatments are given over the same time period. The chemo usually consists of 5-FU with mitomycin C. The mitomycin is given as a short intravenous (IV) injection, usually at the start of radiation treatment and then again near the end, at around 4 to 6 weeks. The 5-FU is often given by a long IV infusion over 4 to 5 days and repeated in 4 to 6 weeks. In some cases, your doctor may suggest internal radiation along with the external beam radiation.

If the cancer has not completely gone away after radiation and chemo have been completed, more treatment may be needed. But it is important to know that it may take several weeks or even months after completing radiation therapy to see the full effects of treatment on the cancer. Doctors may observe any possible remaining cancer for up to 6 months as it may continue to shrink and even go away without further treatment. Sometimes additional chemo (with or without extra radiation) may be given to try to shrink any cancer remaining. Any cancer that is left will then be removed with surgery.

Stages IIIA and IIIB

In most cases, the first treatment will be combined radiation therapy and chemo (as is used in stage I and II disease).

If the tumor shrinks but some cancer remains after the chemoradiation, it may be watched closely for up to 6 months to see if it gets larger. If it does, more treatment is needed. Some patients are given more chemo. The drugs most often used are 5-FU plus cisplatin. Sometimes more radiation is given as well (this is called a radiation boost). Another option is to remove the cancer with surgery. This is most often an APR, but sometimes only a local resection is needed. If the cancer has spread to local lymph nodes, these may be removed with surgery or treated with radiation therapy.

Some doctors treat patients with larger tumors with chemo prior to starting chemoradiation. The chemo often consists of the drugs 5-FU and cisplatin, which may be given for a few cycles to shrink the cancer before starting chemoradiation.

Stage IIIB anal cancer can be hard to treat, so patients with this stage might be helped by taking part in a clinical trial.

Stage IV

In this stage, the cancer has spread to distant organs or tissues. Most often, anal cancer first spreads to the lungs, but it can spread anywhere, including the liver, brain, and bones.

Stage IV anal cancer is not thought to be curable. Treatment is aimed at controlling the disease and relieving symptoms. To do this, doctors may recommend surgery, radiation therapy, chemo, or some combination of these methods. People with this stage of anal cancer might also want to think about taking part in a clinical trial.

Anal melanoma

Melanoma doesn't respond well to chemotherapy or radiation, so surgery to remove the cancer is the main treatment when possible. Early stage anal melanomas are treated with surgery to remove the tumor and a rim of surrounding normal tissue (local excision). If the tumor is large or has grown into deeper tissues (such as the sphincter muscle) a bigger operation, such as an abdominoperineal resection may be needed. If the melanoma has spread to other organs, it is treated like skin melanoma that has spread. For more information about the treatment of advanced melanoma, see our document, Melanoma Skin Cancer.

Recurrent anal cancer

Cancer is called recurrent when it come backs after treatment. Recurrence can be local (in or near the same place it started) or distant (spread to organs such as the lungs or bone). If your cancer returns in the anus or nearby lymph nodes after treatment, your treatment depends on what treatment you had the first time. For example, if you had surgery alone, you may receive radiation therapy and chemo. If you first had chemoradiation, then you can be treated with surgery and/or chemo. Treating recurrent anal cancer often requires an abdominoperineal resection (APR). Again, clinical trials may prove to be valuable for people with recurrent anal cancer.

In some people, the cancer will come back in distant sites or organs in the body. The most common sites are the liver and lungs. Another common site is the lung. The main treatment for this is chemo, but in rare cases surgery to remove the cancer might be an option. The typical chemo drugs used are 5-FU and cisplatin. Chemo might not be curative, but it can help to reduce any symptoms from the disease.

HIV-infected patients

Most people with HIV infection can be given the same treatment as others with anal cancer, and they can have a good outcome. Patients who have advanced HIV disease and weakened immune systems may need to have less intensive chemotherapy.


Last Medical Review: 01/02/2013
Last Revised: 01/02/2013