Last Modified : 2005-10-21
The rectum is part of
the body’s digestive system. The
digestive system removes and processes nutrients (vitamins, minerals,
carbohydrates, fats, proteins, and water) from foods and helps pass waste
material out of the body. The digestive system is made up of the
esophagus,
stomach, and the
small and
large intestines. The first 6 feet of the
large intestine are called the large bowel or colon. The last 6 inches are the rectum and the
anal canal. The anal canal ends at the anus (the opening of the large intestine to the
outside of the body).
enlarge
Anatomy of the lower digestive system, showing the colon and other organs.
The following are possible risk factors for rectal cancer:
These and other symptoms may be caused by rectal cancer. Other conditions may cause the same symptoms. A doctor should be consulted if any of the following problems occur:
Tests used in diagnosing rectal cancer include the following:
enlarge
enlarge
enlarge
enlarge
The prognosis (chance of recovery) and treatment options depend on the following:
The process used to find out whether cancer has spread within the rectum or to other parts of the body is called staging. The information gathered from the staging process determines the stage of the disease. It is important to know the stage in order to plan treatment. The following tests and procedures may be used in the staging process:
enlarge
In stage 0, cancer is found only in the innermost lining of the rectum. Stage 0 cancer is also called carcinoma in situ.
Stage IIn stage I, cancer has spread beyond the innermost lining of the rectum to the second and third layers and involves the inside wall of the rectum, but it has not spread to the outer wall of the rectum or outside the rectum. Stage I rectal cancer is sometimes called Dukes’ A rectal cancer.
Stage IIIn stage II, cancer has spread outside the rectum to nearby tissue, but it has not gone into the lymph nodes (small, bean-shaped structures found throughout the body that filter substances in a fluid called lymph and help fight infection and disease). Stage II rectal cancer is sometimes called Dukes’ B rectal cancer.
Stage IIIIn stage III, cancer has spread to nearby lymph nodes, but it has not spread to other parts of the body. Stage III rectal cancer is sometimes called Dukes’ C rectal cancer.
Stage IVIn stage IV, cancer has spread to other parts of the body, such as the liver, lungs, or ovaries. Stage IV rectal cancer is sometimes called Dukes’ D rectal cancer.
Recurrent rectal cancer is cancer that has recurred (come back) after it has been treated. The cancer may come back in the rectum or in other parts of the body, such as the colon, pelvis, liver, or lungs.
Different types of treatment are available for patients with rectal cancer. Some treatments are standard (the currently used treatment), and some are being tested in clinical trials. Before starting treatment, patients may want to think about taking part in a clinical trial. 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
Clinical trials are taking place in many parts of the country. Information about ongoing clinical trials is available from the NCI Web site. Choosing the most appropriate cancer treatment is a decision that ideally involves the patient, family, and health care team.
Three types of standard treatment are used:Surgery is the most common treatment for all stages of rectal cancer. A doctor may remove the cancer using one of the following types of surgery:
Even if the doctor removes all the cancer that can be seen at the time of the operation, some patients may be given chemotherapy or radiation therapy after surgery to kill any cancer cells that are left. Treatment given after surgery to increase the chances of a cure is called adjuvant therapy.
Radiation therapyRadiation 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 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.
ChemotherapyChemotherapy 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 in the spinal column, 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.
After treatment, a blood test to measure amounts of carcinoembryonic antigen (a substance in the blood that may be increased when cancer is present) may be done to see if the cancer has come back.
New types of treatment are being tested in clinical trials. These include the following:Biologic therapy is a treatment that uses the patient’s immune system to fight cancer. Substances made by the body or made in a laboratory are used to boost, direct, or restore the body’s natural defenses against cancer. This type of cancer treatment is also called biotherapy or immunotherapy.
This summary section refers to specific treatments under study in clinical trials, but it may not mention every new treatment being studied. Information about ongoing clinical trials is available from the NCI Web site.
Treatment of stage 0 (carcinoma in situ) rectal cancer may include the following:
Treatment of stage I rectal cancer may include the following:
Treatment of stage II rectal cancer may include the following:
Information about ongoing clinical trials is available from the NCI Web site.
Treatment of stage III rectal cancer may include the following:
Information about ongoing clinical trials is available from the NCI Web site.
Treatment of stage IV rectal cancer may include the following:
This summary section refers to specific treatments under study in clinical trials, but it may not mention every new treatment being studied. Information about ongoing clinical trials is available from the NCI Web site.
Treatment of recurrent rectal cancer may include the following: