user: What are the treatments for Anal Cancer ?

assistant: Key Points
                    - There are different types of treatment for patients with anal cancer.    - Three types of standard treatment are used:         - Radiation therapy     - Chemotherapy     - Surgery        - Having the human immunodeficiency virus can affect treatment of anal cancer.    - New types of treatment are being tested in clinical trials.          - Radiosensitizers        - Patients may want to think about taking part in a clinical trial.    - Patients can enter clinical trials before, during, or after starting their cancer treatment.    - Follow-up tests may be needed.
                
                
                    There are different types of treatment for patients with anal cancer.
                    Different types of treatments are available for patients with anal cancer. Some treatments are standard (the currently used treatment), and some are being tested in clinical trials. A treatment clinical trial is a research study meant to help improve current treatments or obtain information on new treatments for patients with cancer. When clinical trials show that a new treatment is better than the standard treatment, the new treatment may become the standard treatment. Patients may want to think about taking part in a clinical trial. Some clinical trials are open only to patients who have not started treatment.
                
                
                    Three types of standard treatment are used:
                    Radiation therapy     Radiation therapy is a cancer treatment that uses high-energy x-rays or other types of radiation to kill cancer cells or keep them from growing. 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 placed directly into or near the cancer.           The way the radiation therapy is given depends on the type and stage of the cancer being treated. External and internal radiation therapy are used to treat anal cancer.       Chemotherapy     Chemotherapy is a cancer treatment that uses drugs to stop the growth of cancer cells, either by killing the cells or by stopping the cells from dividing. When chemotherapy is taken by mouth 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 way the chemotherapy is given depends on the type and stage of the cancer being treated.        Surgery            -  Local resection: A surgical procedure in which the tumor 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. Tumors 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 of the body. This is called a colostomy. Lymph nodes that contain cancer may also be removed during this operation.
                
                
                    Having the human immunodeficiency virus can affect treatment of anal cancer.
                    Cancer therapy can further damage the already weakened immune systems of patients who have the human immunodeficiency virus (HIV). For this reason, patients who have anal cancer and HIV are usually treated with lower doses of anticancer drugs and radiation than patients who do not have HIV.
                
                
                    New types of treatment are being tested in clinical trials.
                    This summary section describes treatments that are being studied in clinical trials. It may not mention every new treatment being studied. Information about clinical trials is available from the NCI website.     Radiosensitizers     Radiosensitizers are drugs that make tumor cells more sensitive to radiation therapy. Combining radiation therapy with radiosensitizers may kill more tumor cells.
                
                
                    Patients may want to think about taking part in a clinical trial.
                    For some patients, taking part in a clinical trial may be the best treatment choice. Clinical trials are part of the cancer research process. Clinical trials are done to find out if new cancer treatments are safe and effective or better than the standard treatment.   Many of today's standard treatments for cancer are based on earlier clinical trials. Patients who take part in a clinical trial may receive the standard treatment or be among the first to receive a new treatment.   Patients who take part in clinical trials also help improve the way cancer will be treated in the future. Even when clinical trials do not lead to effective new treatments, they often answer important questions and help move research forward.
                
                
                    Patients can enter clinical trials before, during, or after starting their cancer treatment.
                    Some clinical trials only include patients who have not yet received treatment. Other trials test treatments for patients whose cancer has not gotten better. There are also clinical trials that test new ways to stop cancer from recurring (coming back) or reduce the side effects of cancer treatment.   Clinical trials are taking place in many parts of the country. See the Treatment Options section that follows for links to current treatment clinical trials. These have been retrieved from NCI's listing of clinical trials.
                
                
                    Follow-up tests may be needed.
                    Some of the tests that were done to diagnose the cancer or to find out the stage of the cancer may be repeated. Some tests will be repeated in order to see how well the treatment is working. Decisions about whether to continue, change, or stop treatment may be based on the results of these tests.   Some of the tests will continue to be done from time to time after treatment has ended. The results of these tests can show if your condition has changed or if the cancer has recurred (come back). These tests are sometimes called follow-up tests or check-ups.
                
                
						            Treatment Options by Stage
						            
						                
						                    Stage 0 (Carcinoma in Situ)
						                    Treatment of stage 0 is usually local resection.   Check the list of NCI-supported cancer clinical trials that are now accepting patients with stage 0 anal cancer. For more specific results, refine the search by using other search features, such as the location of the trial, the type of treatment, or the name of the drug. Talk with your doctor about clinical trials that may be right for you. General information about clinical trials is available from the NCI website.
						                
						                
						                    Stage I Anal Cancer
						                    Treatment of stage I anal cancer may include the following:         -  Local resection.    -  External-beam radiation therapy with or without chemotherapy. If cancer remains after treatment, more chemotherapy and radiation therapy may be given to avoid the need for a permanent colostomy.    -  Internal radiation therapy.     -  Abdominoperineal resection, if cancer remains or comes back after treatment with radiation therapy and chemotherapy.     - Internal radiation therapy for cancer that remains after treatment with external-beam radiation therapy.        Patients who have had treatment that saves the sphincter muscles may receive follow-up exams every 3 months for the first 2 years, including rectal exams with endoscopy and biopsy, as needed.   Check the list of NCI-supported cancer clinical trials that are now accepting patients with stage I anal cancer. For more specific results, refine the search by using other search features, such as the location of the trial, the type of treatment, or the name of the drug. Talk with your doctor about clinical trials that may be right for you. General information about clinical trials is available from the NCI website.
						                
						                
						                    Stage II Anal Cancer
						                    Treatment of stage II anal cancer may include the following:         -  Local resection.    -  External-beam radiation therapy with chemotherapy. If cancer remains after treatment, more chemotherapy and radiation therapy may be given to avoid the need for a permanent colostomy.    -  Internal radiation therapy.    -  Abdominoperineal resection, if cancer remains or comes back after treatment with radiation therapy and chemotherapy.     - A clinical trial of new treatment options.        Patients who have had treatment that saves the sphincter muscles may receive follow-up exams every 3 months for the first 2 years, including rectal exams with endoscopy and biopsy, as needed.   Check the list of NCI-supported cancer clinical trials that are now accepting patients with stage II anal cancer. For more specific results, refine the search by using other search features, such as the location of the trial, the type of treatment, or the name of the drug. Talk with your doctor about clinical trials that may be right for you. General information about clinical trials is available from the NCI website.
						                
						                
						                    Stage IIIA Anal Cancer
						                    Treatment of stage IIIA anal cancer may include the following:         -  External-beam radiation therapy with chemotherapy. If cancer remains after treatment, more chemotherapy and radiation therapy may be given to avoid the need for a permanent colostomy.     -  Internal radiation therapy.    -  Abdominoperineal resection, if cancer remains or comes back after treatment with chemotherapy and radiation therapy.    - A clinical trial of new treatment options.        Check the list of NCI-supported cancer clinical trials that are now accepting patients with stage IIIA anal cancer. For more specific results, refine the search by using other search features, such as the location of the trial, the type of treatment, or the name of the drug. Talk with your doctor about clinical trials that may be right for you. General information about clinical trials is available from the NCI website.
						                
						                
						                    Stage IIIB Anal Cancer
						                    Treatment of stage IIIB anal cancer may include the following:         -  External-beam radiation therapy with chemotherapy.     -  Local resection or abdominoperineal resection, if cancer remains or comes back after treatment with chemotherapy and radiation therapy. Lymph nodes may also be removed.    - A clinical trial of new treatment options.        Check the list of NCI-supported cancer clinical trials that are now accepting patients with stage IIIB anal cancer. For more specific results, refine the search by using other search features, such as the location of the trial, the type of treatment, or the name of the drug. Talk with your doctor about clinical trials that may be right for you. General information about clinical trials is available from the NCI website.
						                
						                
						                    Stage IV Anal Cancer
						                    Treatment of stage IV anal cancer may include the following:         -  Surgery as palliative therapy to relieve symptoms and improve the quality of life.    -  Radiation therapy as palliative therapy.    -  Chemotherapy with radiation therapy as palliative therapy.    - A clinical trial of new treatment options.        Check the list of NCI-supported cancer clinical trials that are now accepting patients with stage IV anal cancer. For more specific results, refine the search by using other search features, such as the location of the trial, the type of treatment, or the name of the drug. Talk with your doctor about clinical trials that may be right for you. General information about clinical trials is available from the NCI website.