Rectal Cancer

Rectal Cancer Treatment (PDQ®)–Patient Version

General Information About Rectal Cancer

Key Points

  • Rectal cancer is a disease in which malignant (cancer) cells form in the tissues of the rectum.
  • Health history affects the risk of developing rectal cancer.
  • Signs of rectal cancer include a change in bowel habits or blood in the stool.
  • Tests that examine the rectum and colon are used to diagnose rectal cancer.
  • Certain factors affect prognosis (chance of recovery) and treatment options.

Rectal cancer is a disease in which malignant (cancer) cells form in the tissues of the rectum.

The rectum is part of the body’s digestive system. The digestive system takes in 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 colon (large bowel) is the first part of the large intestine and is about 5 feet long. Together, the rectum and anal canal make up the last part of the large intestine and are 6 to 8 inches long. The anal canal ends at the anus (the opening of the large intestine to the outside of the body).

EnlargeGastrointestinal (digestive) system anatomy; drawing shows the esophagus, liver, stomach, colon, small intestine, rectum, and anus.
Anatomy of the lower gastrointestinal (digestive) system showing the colon, rectum, and anus. Other organs that make up the digestive system are also shown.

Health history affects the risk of developing rectal cancer.

Anything that increases your chance of getting a disease is called a risk factor. Having a risk factor does not mean that you will get cancer; not having risk factors doesn’t mean that you will not get cancer. Talk to your doctor if you think you may be at risk for colorectal cancer.

Risk factors for colorectal cancer include the following:

Older age is a main risk factor for most cancers. The chance of getting cancer increases as you get older.

Signs of rectal cancer include a change in bowel habits or blood in the stool.

These and other signs and symptoms may be caused by rectal cancer or by other conditions. Check with your doctor if you have any of the following:

  • Blood (either bright red or very dark) in the stool.
  • A change in bowel habits.
    • Diarrhea.
    • Constipation.
    • Feeling that the bowel does not empty completely.
    • Stools that are narrower or have a different shape than usual.
  • General abdominal discomfort (frequent gas pains, bloating, fullness, or cramps).
  • Change in appetite.
  • Weight loss for no known reason.
  • Feeling very tired.

Tests that examine the rectum and colon are used to diagnose rectal cancer.

In addition to asking about your personal and family health history and doing a physical exam, your doctor may perform the following tests and procedures:

  • Digital rectal exam (DRE): An exam of the rectum. The doctor or nurse inserts a lubricated, gloved finger into the lower part of the rectum to feel for lumps or anything else that seems unusual. In women, the vagina may also be examined.
  • Colonoscopy: A procedure to look inside the rectum and colon for polyps (small pieces of bulging tissue), abnormal areas, or cancer. A colonoscope is a thin, tube-like instrument with a light and a lens for viewing. It may also have a tool to remove polyps or tissue samples, which are checked under a microscope for signs of cancer.
    EnlargeColonoscopy; drawing shows a colonoscope inserted through the anus and rectum and into the colon. An inset shows a patient lying on a table having a colonoscopy.
    Colonoscopy. A thin, lighted tube is inserted through the anus and rectum and into the colon to look for abnormal areas.
  • Biopsy: The removal of cells or tissues so they can be viewed under a microscope to check for signs of cancer. Tumor tissue that is removed during the biopsy may be checked to see if the patient is likely to have the gene mutation that causes HNPCC. This may help to plan treatment.
  • Immunohistochemistry: A laboratory test that uses antibodies to check for certain antigens (markers) in a sample of a patient’s tissue. The antibodies are usually linked to an enzyme or a fluorescent dye. After the antibodies bind to a specific antigen in the tissue sample, the enzyme or dye is activated, and the antigen can then be seen under a microscope. This type of test is used to help diagnose cancer and to help tell one type of cancer from another type of cancer.
  • Carcinoembryonic antigen (CEA) assay: A test that measures the level of CEA in the blood. CEA is released into the bloodstream from both cancer cells and normal cells. When found in higher than normal amounts, it can be a sign of rectal cancer or other conditions.
  • Microsatellite instability (MSI): A laboratory test in which tumor tissue is checked for cells that may have a defect in genes involved in DNA repair. The findings may indicate whether or not the patient has a type of cancer linked to an inherited cancer syndrome such as HNPCC (also known as Lynch syndrome).

Certain factors affect prognosis (chance of recovery) and treatment options.

The prognosis and treatment options depend on the following:

  • The stage of the cancer (whether it affects the inner lining of the rectum only, involves the whole rectum, or has spread to lymph nodes, nearby organs, or other places in the body).
  • Whether the cancer is related to a defect in genes involved in DNA repair.
  • Whether the tumor has spread into or through the bowel wall.
  • Where the cancer is found in the rectum.
  • Whether the bowel is blocked or has a hole in it.
  • Whether all of the tumor can be removed by surgery.
  • The patient’s general health.
  • Whether the cancer has just been diagnosed or has recurred (come back).

Stages of Rectal Cancer

Key Points

  • After rectal cancer has been diagnosed, tests are done to find out if cancer cells have spread within the rectum or to other parts of the body.
  • There are three ways that cancer spreads in the body.
  • Cancer may spread from where it began to other parts of the body.
  • The following stages are used for rectal cancer:
    • Stage 0 (Carcinoma in Situ)
    • Stage I
    • Stage II
    • Stage III
    • Stage IV
  • Rectal cancer can recur (come back) after it has been treated.

After rectal cancer has been diagnosed, tests are done to find out if cancer cells have spread within the rectum or to other parts of the body.

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:

  • Chest x-ray: An x-ray of the organs and bones inside the chest. An x-ray is a type of energy beam that can go through the body and onto film, making a picture of areas inside the body.
  • Colonoscopy: A procedure to look inside the rectum and colon for polyps (small pieces of bulging tissue). abnormal areas, or cancer. A colonoscope is a thin, tube-like instrument with a light and a lens for viewing. It may also have a tool to remove polyps or tissue samples, which are checked under a microscope for signs of cancer.
    EnlargeColonoscopy; drawing shows a colonoscope inserted through the anus and rectum and into the colon. An inset shows a patient lying on a table having a colonoscopy.
    Colonoscopy. A thin, lighted tube is inserted through the anus and rectum and into the colon to look for abnormal areas.
  • CT scan (CAT scan): A procedure that makes a series of detailed pictures of areas inside the body, such as the abdomen, pelvis, or chest, taken from different angles. The pictures are made by a computer linked to an x-ray machine. A dye may be injected into a vein or swallowed to help the organs or tissues show up more clearly. This procedure is also called computed tomography, computerized tomography, or computerized axial tomography.
  • MRI (magnetic resonance imaging): A procedure that uses a magnet, radio waves, and a computer to make a series of detailed pictures of areas inside the body. This procedure is also called nuclear magnetic resonance imaging (NMRI).
  • PET scan (positron emission tomography scan): A procedure to find malignant tumor cells in the body. A small amount of radioactive glucose (sugar) is injected into a vein. The PET scanner rotates around the body and makes a picture of where glucose is being used in the body. Malignant tumor cells show up brighter in the picture because they are more active and take up more glucose than normal cells do.
  • Endorectal ultrasound: A procedure used to examine the rectum and nearby organs. An ultrasound transducer (probe) is inserted into the rectum and used to bounce high-energy sound waves (ultrasound) off internal tissues or organs and make echoes. The echoes form a picture of body tissues called a sonogram. The doctor can identify tumors by looking at the sonogram. This procedure is also called transrectal ultrasound.

There are three ways that cancer spreads in the body.

Cancer can spread through tissue, the lymph system, and the blood:

  • Tissue. The cancer spreads from where it began by growing into nearby areas.
  • Lymph system. The cancer spreads from where it began by getting into the lymph system. The cancer travels through the lymph vessels to other parts of the body.
  • Blood. The cancer spreads from where it began by getting into the blood. The cancer travels through the blood vessels to other parts of the body.

Cancer may spread from where it began to other parts of the body.

When cancer spreads to another part of the body, it is called metastasis. Cancer cells break away from where they began (the primary tumor) and travel through the lymph system or blood.

  • Lymph system. The cancer gets into the lymph system, travels through the lymph vessels, and forms a tumor (metastatic tumor) in another part of the body.
  • Blood. The cancer gets into the blood, travels through the blood vessels, and forms a tumor (metastatic tumor) in another part of the body.

The metastatic tumor is the same type of cancer as the primary tumor. For example, if rectal cancer spreads to the lung, the cancer cells in the lung are actually rectal cancer cells. The disease is metastatic rectal cancer, not lung cancer.

Many cancer deaths are caused when cancer moves from the original tumor and spreads to other tissues and organs. This is called metastatic cancer. This animation shows how cancer cells travel from the place in the body where they first formed to other parts of the body.

The following stages are used for rectal cancer:

Stage 0 (Carcinoma in Situ)

EnlargeStage 0 colorectal carcinoma in situ; drawing shows a cross-section of the colon/rectum. An inset shows the layers of the colon/rectum wall with abnormal cells in the mucosa layer. Also shown are the submucosa, muscle layers, serosa, a blood vessel, and lymph nodes.
Stage 0 (rectal carcinoma in situ). Abnormal cells are shown in the mucosa of the rectum wall.

In stage 0 rectal cancer, abnormal cells are found in the mucosa (innermost layer) of the rectum wall. These abnormal cells may become cancer and spread into nearby normal tissue. Stage 0 is also called carcinoma in situ.

Stage I

EnlargeStage I colorectal cancer; drawing shows a cross-section of the colon/rectum. An inset shows the layers of the colon/rectum wall with cancer in the mucosa and submucosa. Also shown are the muscle layers, serosa, a blood vessel, and lymph nodes.
Stage I rectal cancer. Cancer has spread from the mucosa of the rectum wall to the submucosa or to the muscle layer.

In stage I rectal cancer, cancer has formed in the mucosa (innermost layer) of the rectum wall and has spread to the submucosa (layer of tissue next to the mucosa) or to the muscle layer of the rectum wall.

Stage II

EnlargeStage II colorectal cancer; drawing shows a cross-section of the colon/rectum and a three-panel inset. Each panel shows the layers of the colon/rectum wall: the mucosa, submucosa, muscle layers, and serosa. Also shown are a blood vessel and lymph nodes. The first panel shows stage IIA with cancer in the mucosa, submucosa, muscle layers, and serosa. The second panel shows stage IIB with cancer in all layers and spreading through the serosa to the visceral peritoneum. The third panel shows stage IIC with cancer in all layers and spreading through the serosa to nearby organs.
Stage II rectal cancer. In stage IIA, cancer has spread through the muscle layer of the rectum wall to the serosa. In stage IIB, cancer has spread through the serosa but has not spread to nearby organs. In stage IIC, cancer has spread through the serosa to nearby organs.

Stage II rectal cancer is divided into stages IIA, IIB, and IIC.

Stage III

Stage III rectal cancer is divided into stages IIIA, IIIB, and IIIC.

EnlargeStage IIIA colorectal cancer; drawing shows a cross-section of the colon/rectum and a two-panel inset. Each panel shows the layers of the colon/rectum wall: the mucosa, submucosa, muscle layers, and serosa. Also shown are a blood vessel and lymph nodes. The first panel shows cancer in the mucosa, submucosa, and muscle layers and in 2 lymph nodes. The second panel shows cancer in the mucosa and submucosa and in 5 lymph nodes.
Stage IIIA rectal cancer. Cancer has spread through the mucosa of the rectum wall to the submucosa and may have spread to the muscle layer, and has spread to one to three nearby lymph nodes or tissues near the lymph nodes. OR, cancer has spread through the mucosa to the submucosa and four to six nearby lymph nodes.

In stage IIIA, cancer has spread:

  • through the mucosa (innermost layer) of the rectum wall to the submucosa (layer of tissue next to the mucosa) or to the muscle layer of the rectum wall. Cancer has spread to one to three nearby lymph nodes or cancer cells have formed in tissue near the lymph nodes; or
  • through the mucosa (innermost layer) of the rectum wall to the submucosa (layer of tissue next to the mucosa). Cancer has spread to four to six nearby lymph nodes.
EnlargeStage IIIB colorectal cancer; drawing shows a cross-section of the colon/rectum and a three-panel inset. Each panel shows the layers of the colon/rectum wall: the mucosa, submucosa, muscle layers, and serosa. Also shown are a blood vessel and lymph nodes. The first panel shows cancer in all layers, in 3 nearby lymph nodes, and in the visceral peritoneum. The second panel shows cancer in all layers and in 5 nearby lymph nodes. The third panel shows cancer in the mucosa, submucosa, and muscle layers and in 7 nearby lymph nodes.
Stage IIIB rectal cancer. Cancer has spread through the muscle layer of the rectum wall to the serosa or has spread through the serosa but not to nearby organs; cancer has spread to one to three nearby lymph nodes or to tissues near the lymph nodes. OR, cancer has spread to the muscle layer or to the serosa, and to four to six nearby lymph nodes. OR, cancer has spread through the mucosa to the submucosa and may have spread to the muscle layer; cancer has spread to seven or more nearby lymph nodes.

In stage IIIB, cancer has spread:

  • through the muscle layer of the rectum wall to the serosa (outermost layer) of the rectum wall or has spread through the serosa to the tissue that lines the organs in the abdomen (visceral peritoneum). Cancer has spread to one to three nearby lymph nodes or cancer cells have formed in tissue near the lymph nodes; or
  • to the muscle layer or to the serosa (outermost layer) of the rectum wall. Cancer has spread to four to six nearby lymph nodes; or
  • through the mucosa (innermost layer) of the rectum wall to the submucosa (layer of tissue next to the mucosa) or to the muscle layer of the rectum wall. Cancer has spread to seven or more nearby lymph nodes.
EnlargeStage IIIC colorectal cancer; drawing shows a cross-section of the colon/rectum and a three-panel inset. Each panel shows the layers of the colon/rectum wall: the mucosa, submucosa, muscle layers, and serosa. Also shown are a blood vessel and lymph nodes. The first panel shows cancer in all layers, in 4 lymph nodes, and in the visceral peritoneum. The second panel shows cancer in all layers and in 7 lymph nodes. The third panel shows cancer in all layers, in 2 lymph nodes, and spreading to nearby organs.
Stage IIIC rectal cancer. Cancer has spread through the serosa of the rectum wall but not to nearby organs; cancer has spread to four to six nearby lymph nodes. OR, cancer has spread through the muscle layer to the serosa or has spread through the serosa but not to nearby organs; cancer has spread to seven or more nearby lymph nodes. OR, cancer has spread through the serosa to nearby organs and to one or more nearby lymph nodes or to tissues near the lymph nodes.

In stage IIIC, cancer has spread:

  • through the serosa (outermost layer) of the rectum wall to the tissue that lines the organs in the abdomen (visceral peritoneum). Cancer has spread to four to six nearby lymph nodes; or
  • through the muscle layer of the rectum wall to the serosa (outermost layer) of the rectum wall or has spread through the serosa to the tissue that lines the organs in the abdomen (visceral peritoneum). Cancer has spread to seven or more nearby lymph nodes; or
  • through the serosa (outermost layer) of the rectum wall to nearby organs. Cancer has spread to one or more nearby lymph nodes or cancer cells have formed in tissue near the lymph nodes.

Stage IV

Stage IV rectal cancer is divided into stages IVA, IVB, and IVC.

EnlargeStage IV rectal cancer; drawing shows other parts of the body where rectal cancer may spread, including the distant lymph nodes, lung, liver, abdominal wall, and prostate. An inset shows cancer cells spreading from the rectum, through the blood and lymph system, to another part of the body where metastatic cancer has formed.
Stage IV rectal cancer. The cancer has spread through the blood and lymph nodes to other parts of the body, such as the lung, liver, abdominal wall, or prostate.

Rectal cancer can recur (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.

Treatment Option Overview

Key Points

  • There are different types of treatment for patients with rectal cancer.
  • The following types of treatment are used:
    • Surgery
    • Radiation therapy
    • Chemotherapy
    • Active surveillance
    • Targeted therapy
    • Immunotherapy
  • Other types of treatment are being tested in clinical trials.
  • Treatment for rectal cancer may cause side effects.
  • 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 rectal cancer.

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. 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.

The following types of treatment are used:

Surgery

Surgery is the most common treatment for all stages of rectal cancer. The cancer is removed using one of the following types of surgery:

  • Polypectomy: If the cancer is found in a polyp (a small piece of bulging tissue), the polyp is often removed during a colonoscopy.
  • Local excision: If the cancer is found on the inside surface of the rectum and has not spread into the wall of the rectum, the cancer and a small amount of surrounding healthy tissue is removed.
  • Resection: If the cancer has spread into the wall of the rectum, the section of the rectum with cancer and nearby healthy tissue is removed. Sometimes the tissue between the rectum and the abdominal wall is also removed. The lymph nodes near the rectum are removed and checked under a microscope for signs of cancer.
  • Radiofrequency ablation: The use of a special probe with tiny electrodes that kill cancer cells. Sometimes the probe is inserted directly through the skin and only local anesthesia is needed. In other cases, the probe is inserted through an incision in the abdomen. This is done in the hospital with general anesthesia.
  • Cryosurgery: A treatment that uses an instrument to freeze and destroy abnormal tissue. This type of treatment is also called cryotherapy.
  • Pelvic exenteration: If the cancer has spread to other organs near the rectum, the lower colon, rectum, and bladder are removed. In women, the cervix, vagina, ovaries, and nearby lymph nodes may be removed. In men, the prostate may be removed. Artificial openings (stoma) are made for urine and stool to flow from the body to a collection bag.

After the cancer is removed, the surgeon will either:

  • do an anastomosis (sew the healthy parts of the rectum together, sew the remaining rectum to the colon, or sew the colon to the anus);
    EnlargeThree-panel drawing showing rectal cancer surgery with anastomosis; the first panel shows area of rectum with cancer, the middle panel shows cancer and nearby tissue removed, and the last panel shows the colon and anus joined.
    Resection of the rectum with anastomosis. The rectum and part of the colon are removed, and then the colon and anus are joined.
    or
  • make a stoma (an opening) from the rectum to the outside of the body for waste to pass through. This procedure is done if the cancer is too close to the anus and is called a colostomy. A bag is placed around the stoma to collect the waste. Sometimes the colostomy is needed only until the rectum has healed, and then it can be reversed. If the entire rectum is removed, however, the colostomy may be permanent.

Radiation therapy and/or chemotherapy may be given before surgery to shrink the tumor, make it easier to remove the cancer, and help with bowel control after surgery. Treatment given before surgery is called neoadjuvant therapy. After all the cancer that can be seen at the time of the surgery is removed, some patients may be given radiation therapy and/or chemotherapy after surgery to kill any cancer cells that are left. Treatment given after the surgery, to lower the risk that the cancer will come back, is called adjuvant therapy.

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. External radiation therapy uses a machine outside the body to send radiation toward the cancer.

Short-course preoperative radiation therapy is used in some types of rectal cancer. This treatment uses fewer and lower doses of radiation than standard treatment, followed by surgery several days after the last dose.

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 in the cerebrospinal fluid, an organ, or a body cavity such as the abdomen, the drugs mainly affect cancer cells in those areas (regional chemotherapy).

Chemoembolization of the hepatic artery is a type of regional chemotherapy that may be used to treat cancer that has spread to the liver. This is done by blocking the hepatic artery (the main artery that supplies blood to the liver) and injecting anticancer drugs between the blockage and the liver. The liver’s arteries then carry the drugs into the liver. Only a small amount of the drug reaches other parts of the body. The blockage may be temporary or permanent, depending on what is used to block the artery. The liver continues to receive some blood from the hepatic portal vein, which carries blood from the stomach and intestine.

The way the chemotherapy is given depends on the type and stage of the cancer being treated.

For more information, see Drugs Approved for Colon and Rectal Cancer.

Active surveillance

Active surveillance is closely following a patient's condition without giving any treatment unless there are changes in test results. It is used to find early signs that the condition is getting worse. In active surveillance, patients are given certain exams and tests to check if the cancer is growing. When the cancer begins to grow, treatment is given to cure the cancer. Tests include the following:

Targeted therapy

Targeted therapy is a type of treatment that uses drugs or other substances to identify and attack specific cancer cells.

Types of targeted therapies used in the treatment of rectal cancer include the following:

  • Monoclonal antibodies: Monoclonal antibodies are immune system proteins made in the laboratory to treat many diseases, including cancer. As a cancer treatment, these antibodies can attach to a specific target on cancer cells or other cells that may help cancer cells grow. The antibodies are able to then kill the cancer cells, block their growth, or keep them from spreading. Monoclonal antibodies are given by infusion. They may be used alone or to carry drugs, toxins, or radioactive material directly to cancer cells.

    There are different types of monoclonal antibody therapy:

    How do monoclonal antibodies work to treat cancer? This video shows how monoclonal antibodies, such as trastuzumab, pembrolizumab, and rituximab, block molecules cancer cells need to grow, flag cancer cells for destruction by the body’s immune system, or deliver harmful substances to cancer cells.
  • Angiogenesis inhibitors: Angiogenesis inhibitors stop the growth of new blood vessels that tumors need to grow.
    • Ziv-aflibercept is a vascular endothelial growth factor trap that blocks an enzyme needed for the growth of new blood vessels in tumors.
    • Regorafenib is used to treat colorectal cancer that has spread to other parts of the body and has not gotten better with other treatment. It blocks the action of certain proteins, including vascular endothelial growth factor. This may help keep cancer cells from growing and may kill them. It may also prevent the growth of new blood vessels that tumors need to grow.
  • Protein kinase inhibitor therapy: This treatment blocks a protein needed for cancer cells to divide. Protein kinase inhibitors include:

For more information, see Drugs Approved for Colon and Rectal Cancer.

Immunotherapy

Immunotherapy 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.

Immune checkpoint inhibitor therapy: Immune checkpoint inhibitors block proteins called checkpoints that are made by some types of immune system cells, such as T cells, and some cancer cells. These checkpoints help keep immune responses from being too strong and sometimes can keep T cells from killing cancer cells. When these checkpoints are blocked, T cells can kill cancer cells better. They are used to treat some patients with metastatic colorectal cancer.

There are two types of immune checkpoint inhibitor therapy:

  • CTLA-4 inhibitor therapy: CTLA-4 is a protein on the surface of T cells that helps keep the body’s immune responses in check. When CTLA-4 attaches to another protein called B7 on a cancer cell, it stops the T cell from killing the cancer cell. CTLA-4 inhibitors attach to CTLA-4 and allow the T cells to kill cancer cells. Ipilimumab is a type of CTLA-4 inhibitor.
    EnlargeImmune checkpoint inhibitor; the panel on the left shows the binding of the T-cell receptor (TCR) to antigen and MHC proteins on the antigen-presenting cell (APC) and the binding of CD28 on the T cell to B7-1/B7-2 on the APC. It also shows the binding of B7-1/B7-2 to CTLA-4 on the T cell, which keeps the T cells in the inactive state. The panel on the right shows immune checkpoint inhibitor (anti-CTLA antibody) blocking the binding of B7-1/B7-2 to CTLA-4, which allows the T cells to be active and to kill tumor cells.
    Immune checkpoint inhibitor. Checkpoint proteins, such as B7-1/B7-2 on antigen-presenting cells (APC) and CTLA-4 on T cells, help keep the body’s immune responses in check. When the T-cell receptor (TCR) binds to antigen and major histocompatibility complex (MHC) proteins on the APC and CD28 binds to B7-1/B7-2 on the APC, the T cell can be activated. However, the binding of B7-1/B7-2 to CTLA-4 keeps the T cells in the inactive state so they are not able to kill tumor cells in the body (left panel). Blocking the binding of B7-1/B7-2 to CTLA-4 with an immune checkpoint inhibitor (anti-CTLA-4 antibody) allows the T cells to be active and to kill tumor cells (right panel).
  • PD-1 and PD-L1 inhibitor therapy: PD-1 is a protein on the surface of T cells that helps keep the body’s immune responses in check. PD-L1 is a protein found on some types of cancer cells. When PD-1 attaches to PD-L1, it stops the T cell from killing the cancer cell. PD-1 and PD-L1 inhibitors keep PD-1 and PD-L1 proteins from attaching to each other. This allows the T cells to kill cancer cells. Pembrolizumab and nivolumab are types of PD-1 inhibitors. Dostarlimab is a PD-1 inhibitor being studied in clinical trials.
EnlargeImmune checkpoint inhibitor; the panel on the left shows the binding of proteins PD-L1 (on the tumor cell) to PD-1 (on the T cell), which keeps T cells from killing tumor cells in the body. Also shown are a tumor cell antigen and T cell receptor. The panel on the right shows immune checkpoint inhibitors (anti-PD-L1 and anti-PD-1) blocking the binding of PD-L1 to PD-1, which allows the T cells to kill tumor cells.
Immune checkpoint inhibitor. Checkpoint proteins, such as PD-L1 on tumor cells and PD-1 on T cells, help keep immune responses in check. The binding of PD-L1 to PD-1 keeps T cells from killing tumor cells in the body (left panel). Blocking the binding of PD-L1 to PD-1 with an immune checkpoint inhibitor (anti-PD-L1 or anti-PD-1) allows the T cells to kill tumor cells (right panel).
Immunotherapy uses the body’s immune system to fight cancer. This animation explains one type of immunotherapy that uses immune checkpoint inhibitors to treat cancer.

For more information, see Drugs Approved for Colon and Rectal Cancer.

Other types of treatment are being tested in clinical trials.

Information about clinical trials is available from the NCI website.

Treatment for rectal cancer may cause side effects.

For information about side effects caused by treatment for cancer, see our Side Effects page.

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. Information about clinical trials supported by NCI can be found on NCI’s clinical trials search webpage. Clinical trials supported by other organizations can be found on the ClinicalTrials.gov website.

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.

After treatment for rectal cancer, 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.

Treatment of Stage 0 (Carcinoma in Situ)

For information about the treatments listed below, see the Treatment Option Overview section.

Treatment of stage 0 may include the following:

Use our clinical trial search to find NCI-supported cancer clinical trials that are accepting patients. You can search for trials based on the type of cancer, the age of the patient, and where the trials are being done. General information about clinical trials is also available.

Treatment of Stage I Rectal Cancer

For information about the treatments listed below, see the Treatment Option Overview section.

Treatment of stage I rectal cancer may include the following:

Use our clinical trial search to find NCI-supported cancer clinical trials that are accepting patients. You can search for trials based on the type of cancer, the age of the patient, and where the trials are being done. General information about clinical trials is also available.

Treatment of Stages II and III Rectal Cancer

For information about the treatments listed below, see the Treatment Option Overview section.

Treatment of stage II and stage III rectal cancer may include the following:

Use our clinical trial search to find NCI-supported cancer clinical trials that are accepting patients. You can search for trials based on the type of cancer, the age of the patient, and where the trials are being done. General information about clinical trials is also available.

Treatment of Stage IV and Recurrent Rectal Cancer

For information about the treatments listed below, see the Treatment Option Overview section.

Treatment of stage IV and recurrent rectal cancer may include the following:

Treatment of rectal cancer that has spread to other organs depends on where the cancer has spread.

  • Treatment for areas of cancer that have spread to the liver includes the following:
    • Surgery to remove the tumor. Chemotherapy may be given before surgery, to shrink the tumor.
    • Cryosurgery or radiofrequency ablation.
    • Chemoembolization and/or systemic chemotherapy.
    • A clinical trial of chemoembolization combined with radiation therapy to the tumors in the liver.

Use our clinical trial search to find NCI-supported cancer clinical trials that are accepting patients. You can search for trials based on the type of cancer, the age of the patient, and where the trials are being done. General information about clinical trials is also available.

To Learn More About Rectal Cancer

About This PDQ Summary

About PDQ

Physician Data Query (PDQ) is the National Cancer Institute's (NCI's) comprehensive cancer information database. The PDQ database contains summaries of the latest published information on cancer prevention, detection, genetics, treatment, supportive care, and complementary and alternative medicine. Most summaries come in two versions. The health professional versions have detailed information written in technical language. The patient versions are written in easy-to-understand, nontechnical language. Both versions have cancer information that is accurate and up to date and most versions are also available in Spanish.

PDQ is a service of the NCI. The NCI is part of the National Institutes of Health (NIH). NIH is the federal government’s center of biomedical research. The PDQ summaries are based on an independent review of the medical literature. They are not policy statements of the NCI or the NIH.

Purpose of This Summary

This PDQ cancer information summary has current information about the treatment of rectal cancer. It is meant to inform and help patients, families, and caregivers. It does not give formal guidelines or recommendations for making decisions about health care.

Reviewers and Updates

Editorial Boards write the PDQ cancer information summaries and keep them up to date. These Boards are made up of experts in cancer treatment and other specialties related to cancer. The summaries are reviewed regularly and changes are made when there is new information. The date on each summary ("Updated") is the date of the most recent change.

The information in this patient summary was taken from the health professional version, which is reviewed regularly and updated as needed, by the PDQ Adult Treatment Editorial Board.

Clinical Trial Information

A clinical trial is a study to answer a scientific question, such as whether one treatment is better than another. Trials are based on past studies and what has been learned in the laboratory. Each trial answers certain scientific questions in order to find new and better ways to help cancer patients. During treatment clinical trials, information is collected about the effects of a new treatment and how well it works. If a clinical trial shows that a new treatment is better than one currently being used, the new treatment may become "standard." 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.

Clinical trials can be found online at NCI's website. For more information, call the Cancer Information Service (CIS), NCI's contact center, at 1-800-4-CANCER (1-800-422-6237).

Permission to Use This Summary

PDQ is a registered trademark. The content of PDQ documents can be used freely as text. It cannot be identified as an NCI PDQ cancer information summary unless the whole summary is shown and it is updated regularly. However, a user would be allowed to write a sentence such as “NCI’s PDQ cancer information summary about breast cancer prevention states the risks in the following way: [include excerpt from the summary].”

The best way to cite this PDQ summary is:

PDQ® Adult Treatment Editorial Board. PDQ Rectal Cancer Treatment. Bethesda, MD: National Cancer Institute. Updated <MM/DD/YYYY>. Available at: /types/colorectal/patient/rectal-treatment-pdq. Accessed <MM/DD/YYYY>. [PMID: 26389378]

Images in this summary are used with permission of the author(s), artist, and/or publisher for use in the PDQ summaries only. If you want to use an image from a PDQ summary and you are not using the whole summary, you must get permission from the owner. It cannot be given by the National Cancer Institute. Information about using the images in this summary, along with many other images related to cancer can be found in Visuals Online. Visuals Online is a collection of more than 3,000 scientific images.

Disclaimer

The information in these summaries should not be used to make decisions about insurance reimbursement. More information on insurance coverage is available on Cancer.gov on the Managing Cancer Care page.

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More information about contacting us or receiving help with the Cancer.gov website can be found on our Contact Us for Help page. Questions can also be submitted to Cancer.gov through the website’s E-mail Us.

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