Colorectal (Bowel) Cancer

Colorectal Cancer

 

The following information is provided by the US National Cancer Institute.

Definition of colorectal cancer: Cancer that develops in the colon (the longest part of the large intestine) and/or the rectum (the last several inches of the large intestine before the anus).

colon cancer: Cancer that forms in the tissues of the colon (the longest part of the large intestine). Most colon cancers are adenocarcinomas (cancers that begin in cells that make and release mucus and other fluids).

rectal cancer: Cancer that forms in the tissues of the rectum (the last several inches of the large intestine closest to the anus).


General Information About Colon Cancer

Colon cancer is a disease in which malignant (cancer) cells form in the tissues of the colon.

The colon 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 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 about 6-8 inches long. The anal canal ends at the anus (the opening of the large intestine to the outside of the body).

Health history can affect the risk of developing colon 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:

  • Having a family history of colon or rectal cancer in a first-degree relative (parent, sibling, or child).
  • Having a personal history of cancer of the colon, rectum, or ovary.
  • Having a personal history of high-risk adenomas (colorectal polyps that are 1 centimeter or larger in size or that have cells that look abnormal under a microscope).
  • Having inherited changes in certain genes that increase the risk of familial adenomatous polyposis (FAP) or Lynch syndrome (hereditary nonpolyposis colorectal cancer).
  • Having a personal history of chronic ulcerative colitis or Crohn disease for 8 years or more.
  • Having three or more alcoholic drinks per day.
  • Smoking cigarettes.
  • Being black.
  • Being obese.
  • Older age is a main risk factor for most cancers. The chance of getting cancer increases as you get older.

    What are the symptoms of Colon Cancer?

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

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

    • A change in bowel habits.
    • Blood (either bright red or very dark) in the stool.
    • Diarrhea, constipation, or feeling that the bowel does not empty all the way.
    • Stools that are narrower than usual.
    • Frequent gas pains, bloating, fullness, or cramps.
    • Weight loss for no known reason.
    • Feeling very tired.
    • Vomiting.

    What Tests are used to diagnose Colon Cancer?

    The following tests and procedures may be used:

    • Physical exam and history : An exam of the body to check general signs of health, including checking for signs of disease, such as lumps or anything else that seems unusual. A history of the patient’s health habits and past illnesses and treatments will also be taken.
    • Digital rectal exam : An exam of the rectum. The doctor or nurse inserts a lubricated, gloved finger into the rectum to feel for lumps or anything else that seems unusual.
    • Fecal occult blood test (FOBT): A test to check stool (solid waste) for blood that can only be seen with a microscope. A small sample of stool is placed on a special card or in a special container and returned to the doctor or laboratory for testing. Blood in the stool may be a sign of polyps, cancer, or other conditions.
      There are two types of FOBTs:
    • Guaiac FOBT : The sample of stool on the special card is tested with a chemical. If there is blood in the stool, the special card changes color.
    • Immunochemical FOBT : A liquid is added to the stool sample. This mixture is injected into a machine that contains antibodies that can detect blood in the stool. If there is blood in the stool, a line appears in a window in the machine. This test is also called fecal immunochemical test or FIT.
  • Barium enema : A series of x-rays of the lower gastrointestinal tract. A liquid that contains barium (a silver-white metallic compound) is put into the rectum. The barium coats the lower gastrointestinal tract and x-rays are taken. This procedure is also called a lower GI series.
  • Sigmoidoscopy : A procedure to look inside the rectum and sigmoid (lower) colon for polyps (small areas of bulging tissue), other abnormal areas, or cancer. A sigmoidoscope is inserted through the rectum into the sigmoid colon. A sigmoidoscope 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.
  • Colonoscopy : A procedure to look inside the rectum and colon for polyps, abnormal areas, or cancer. A colonoscope is inserted through the rectum into the colon. 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.
  • Virtual colonoscopy : A procedure that uses a series of x-rays called computed tomography to make a series of pictures of the colon. A computer puts the pictures together to create detailed images that may show polyps and anything else that seems unusual on the inside surface of the colon. This test is also called colonography or CT colonography.
  • Biopsy : The removal of cells or tissues so they can be viewed under a microscope by a pathologist to check for signs of cancer.
  • Certain factors affect prognosis (chance of recovery) and treatment options.

    The prognosis (chance of recovery) and treatment options depend on the following:

    • The stage of the cancer (whether the cancer is in the inner lining of the colon only or has spread through the colon wall, or has spread to lymph nodes or other places in the body).
    • Whether the cancer has blocked or made a hole in the colon.
    • Whether there are any cancer cells left after surgery.
    • Whether the cancer has recurred.
    • The patient’s general health.

    The prognosis also depends on the blood levels of carcinoembryonic antigen (CEA) before treatment begins. CEA is a substance in the blood that may be increased when cancer is present.

    Stages of Colon Cancer

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

    The process used to find out if cancer has spread within the colon 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:

    • CT scan (CAT scan): A procedure that makes a series of detailed pictures of areas inside the body, such as the abdomen 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 colon. A substance called gadolinium is injected into the patient through a vein. The gadolinium collects around the cancer cells so they show up brighter in the picture. 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.
    • 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.
    • Surgery : A procedure to remove the tumor and see how far it has spread through the colon.
    • Lymph node biopsy : The removal of all or part of a lymph node. A pathologist views the tissue under a microscope to look for cancer cells.
    • Complete blood count (CBC): A procedure in which a sample of blood is drawn and checked for the following:
      • The number of red blood cells, white blood cells, and platelets.
      • The amount of hemoglobin (the protein that carries oxygen) in the red blood cells.
      • The portion of the blood sample made up of red blood cells.
    • 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 colon cancer or other conditions.

    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 colon cancer spreads to the lung, the cancer cells in the lung are actually colon cancer cells. The disease is metastatic colon cancer, not lung cancer.

    The following stages are used for colon cancer:

    Stage 0 (Carcinoma in Situ)

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

    Stage I

    In stage I, cancer has formed in the mucosa (innermost layer) of the colon wall and has spread to the submucosa (layer of tissue under the mucosa). Cancer may have spread to the muscle layer of the colon wall.

    Stage II

    Stage II colon cancer is divided into stage IIA, stage IIB, and stage IIC.

    • Stage IIA: Cancer has spread through the muscle layer of the colon wall to the serosa (outermost layer) of the colon wall.
    • Stage IIB: Cancer has spread through the serosa (outermost layer) of the colon wall but has not spread to nearby organs.
    • Stage IIC: Cancer has spread through the serosa (outermost layer) of the colon wall to nearby organs.

    Stage III

    Stage III colon cancer is divided into stage IIIA, stage IIIB, and stage IIIC.

    • In stage IIIA:
    • Cancer may have spread through the mucosa (innermost layer) of the colon wall to the submucosa (layer of tissue under the mucosa) and may have spread to the muscle layer of the colon wall. Cancer has spread to at least one but not more than 3 nearby lymph nodes or cancer cells have formed in tissues near the lymph nodes; or
    • Cancer has spread through the mucosa (innermost layer) of the colon wall to the submucosa (layer of tissue under the mucosa). Cancer has spread to at least 4 but not more than 6 nearby lymph nodes.

    In stage IIIB:

    • Cancer has spread through the muscle layer of the colon wall to the serosa (outermost layer) of the colon wall or has spread through the serosa but not to nearby organs. Cancer has spread to at least one but not more than 3 nearby lymph nodes or cancer cells have formed in tissues near the lymph nodes; or
    • Cancer has spread to the muscle layer of the colon wall or to the serosa (outermost layer) of the colon wall. Cancer has spread to at least 4 but not more than 6 nearby lymph nodes; or
    • Cancer has spread through the mucosa (innermost layer) of the colon wall to the submucosa (layer of tissue under the mucosa) and may have spread to the muscle layer of the colon wall. Cancer has spread to 7 or more nearby lymph nodes.

    In stage IIIC:

    • Cancer has spread through the serosa (outermost layer) of the colon wall but has not spread to nearby organs. Cancer has spread to at least 4 but not more than 6 nearby lymph nodes; or
    • Cancer has spread through the muscle layer of the colon wall to the serosa (outermost layer) of the colon wall or has spread through the serosa but has not spread to nearby organs. Cancer has spread to 7 or more nearby lymph nodes; or
    • Cancer has spread through the serosa (outermost layer) of the colon wall and has spread to nearby organs. Cancer has spread to one or more nearby lymph nodes or cancer cells have formed in tissues near the lymph nodes.

    Stage IV

    Stage IV colon cancer is divided into stage IVA and stage IVB.

    • Stage IVA: Cancer may have spread through the colon wall and may have spread to nearby organs or lymph nodes. Cancer has spread to one organ that is not near the colon, such as the liver, lung, or ovary, or to a distant lymph node.
    • Stage IVB: Cancer may have spread through the colon wall and may have spread to nearby organs or lymph nodes. Cancer has spread to more than one organ that is not near the colon or into the lining of the abdominal wall.

    Recurrent Colon Cancer

    Recurrent colon cancer is cancer that has recurred (come back) after it has been treated. The cancer may come back in the colon or in other parts of the body, such as the liver, lungs, or both.

    Treatment for Colon cancer.

    There are different types of treatment for patients with colon cancer.

    Different types of treatment are available for patients with colon 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.

    Six types of standard treatment are used:

    Surgery

    Surgery (removing the cancer in an operation) is the most common treatment for all stages of colon cancer. A doctor may remove the cancer using one of the following types of surgery:

    • Local excision: If the cancer is found at a very early stage, the doctor may remove it without cutting through the abdominal wall. Instead, the doctor may put a tube with a cutting tool through the rectum into the colon and cut the cancer out. This is called a local excision. If the cancer is found in a polyp (a small bulging area of tissue), the operation is called a polypectomy.
    • Resection of the colon with anastomosis: If the cancer is larger, the doctor will perform a partial colectomy (removing the cancer and a small amount of healthy tissue around it). The doctor may then perform an anastomosis (sewing the healthy parts of the colon together). The doctor will also usually remove lymph nodes near the colon and examine them under a microscope to see whether they contain cancer.Enlarge
    • Resection of the colon with colostomy: If the doctor is not able to sew the 2 ends of the colon back together, a stoma (an opening) is made on the outside of the body for waste to pass through. This procedure is called a colostomy. A bag is placed around the stoma to collect the waste. Sometimes the colostomy is needed only until the lower colon has healed, and then it can be reversed. If the doctor needs to remove the entire lower colon, however, the colostomy may be permanent.

    After 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 the surgery, to lower the risk that the cancer will come back, is called adjuvant therapy.

    Radiofrequency ablation

    Radiofrequency ablation is 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

    Cryosurgery is a treatment that uses an instrument to freeze and destroy abnormal tissue. This type of treatment is also called cryotherapy.

    Chemotherapy

    Chemotherapy is a cancer treatment that uses drugs to stop the growth of cancer cells, either by killing the cells or by stopping them 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).

    Chemoembolization of the hepatic artery may be used to treat cancer that has spread to the liver. This involves 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 deliver the drugs throughout 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.

    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.

    Targeted therapy

    Targeted therapy is a type of treatment that uses drugs or other substances to identify and attack specific cancer cells without harming normal cells.

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

    • Monoclonal antibodies: Monoclonal antibodies are made in the laboratory from a single type of immune system cell. These antibodies can identify substances on cancer cells or normal substances that may help cancer cells grow. The antibodies attach to the substances and 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:
    • Vascular endothelial growth factor (VEGF) inhibitor therapy: Cancer cells make a substance called VEGF, which causes new blood vessels to form (angiogenesis) and helps the cancer grow. VEGF inhibitors block VEGF and stop new blood vessels from forming. This may kill cancer cells because they need new blood vessels to grow. Bevacizumab and ramucirumab are VEGF inhibitors and angiogenesis inhibitors.
    • Epidermal growth factor receptor (EGFR) inhibitor therapy: EGFRs are proteins found on the surface of certain cells, including cancer cells. Epidermal growth factor attaches to the EGFR on the surface of the cell and causes the cells to grow and divide. EGFR inhibitors block the receptor and stop the epidermal growth factor from attaching to the cancer cell. This stops the cancer cell from growing and dividing. Cetuximab and panitumumab are EGFR inhibitors.
    • Immune checkpoint inhibitor therapy: PD-1 is a protein on the surface of T cells that helps keep the body’s immune responses in check. When PD-1 attaches to another protein called PDL-1 on a cancer cell, it stops the T cell from killing the cancer cell. PD-1 inhibitors attach to PDL-1 and allow the T cells to kill cancer cells. Pembrolizumab is a type of immune checkpoint inhibitor.
  • 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.
  • 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. Patients who take part in a clinical trial may receive the standard treatment or be among the first to receive a new 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.

    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. This is sometimes called re-staging.

    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 for Colon Cancer

    Stage 0 (Carcinoma in Situ)

    Treatment of stage 0 (carcinoma in situ) may include the following types of surgery:

    • Local excision or simple polypectomy.
    • Resection and anastomosis. This is done when the tumor is too large to remove by local excision.

    Stage I Colon Cancer

    Treatment of stage I colon cancer usually includes the following:

    • Resection and anastomosis.

    Stage II Colon Cancer

    Treatment of stage II colon cancer may include the following:

    • Resection and anastomosis.

    Stage III Colon Cancer

    Treatment of stage III colon cancer may include the following:

    • Resection and anastomosis which may be followed by chemotherapy.
    • Clinical trials of new chemotherapy regimens after surgery.

    Stage IV and Recurrent Colon Cancer

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

    • Local excision for tumors that have recurred.
    • Resection with or without anastomosis.
    • Surgery to remove parts of other organs, such as the liver, lungs, and ovaries, where the cancer may have recurred or spread. Treatment of cancer that has spread to the liver may also include the following:
      • Chemotherapy given before surgery to shrink the tumor, after surgery, or both before and after.
      • Radiofrequency ablation or cryosurgery, for patients who cannot have surgery.
      • Chemoembolization of the hepatic artery.
    • Radiation therapy or chemotherapy may be offered to some patients as palliative therapy to relieve symptoms and improve quality of life.
    • Chemotherapy and/or targeted therapy with a monoclonal antibody or an angiogenesis inhibitor.
    • Clinical trials of chemotherapy and/or targeted therapy.

    Updated: May 4, 2018


    General Information About Rectal Cancer

    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 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 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 6-8 inches long. The anal canal ends at the anus (the opening of the large intestine to the outside of the body).

    Age and family history can affect the risk of 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 with your doctor if you think you may be at risk. The following are possible risk factors for rectal cancer:

  • Having a family history of colon or rectal cancer in a first-degree relative (parent, sibling, or child).
  • Having a personal history of cancer of the colon, rectum, or ovary.
  • Having a personal history of high-risk adenomas (colorectal polyps that are 1 centimeter or larger in size or that have cells that look abnormal under a microscope).
  • Having inherited changes in certain genes that increase the risk of familial adenomatous polyposis (FAP) or Lynch syndrome (hereditary nonpolyposis colorectal cancer).
  • Having a personal history of chronic ulcerative colitis or Crohn disease for 8 years or more.
  • Having three or more alcoholic drinks per day.
  • Smoking cigarettes.
  • Being black.
  • Being obese.
  • Older age is a main risk factor for most cancers. The chance of getting cancer increases as you get older.

    What are the symptoms of Rectal Cancer?

    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:

    • 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.
    • Blood (either bright red or very dark) in the stool.
    • General abdominal discomfort (frequent gas pains, bloating, fullness, or cramps).
    • Change in appetite.
    • Weight loss for no known reason.
    • Feeling very tired.

    What Tests are used to diagnose Rectal Cancer?

    Tests used to diagnose rectal cancer include the following:

    • Physical exam and history : An exam of the body to check general signs of health, including checking for signs of disease, such as lumps or anything else that seems unusual. A history of the patient’s health habits and past illnesses and treatments will also be taken.
    • 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.
    • 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. The following tests may be used:
      • Reverse-transcription polymerase chain reaction (RT-PCR) test: A laboratory test in which cells in a sample of tissue are studied using chemicals to look for certain changes in the structure or function of genes.
      • Immunohistochemistry : A test that uses antibodies to check for certain antigens in a sample of tissue. The antibody is usually linked to a radioactive substance or a dye that causes the tissue to light up under a microscope. This type of test may be used to tell the difference between different types 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

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

    The prognosis (chance of recovery) 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 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

    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.
    • 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.

    Stages of rectal cancer:

    Stage 0 (Carcinoma in Situ)

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

    Stage I

    In stage I, cancer has formed in the mucosa (innermost layer) of the rectum wall and has spread to the submucosa (layer of tissue under the mucosa). Cancer may have spread to the muscle layer of the rectum wall.

    Stage II

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

    • Stage IIA: Cancer has spread through the muscle layer of the rectum wall to the serosa (outermost layer) of the rectum wall.
    • Stage IIB: Cancer has spread through the serosa (outermost layer) of the rectum wall but has not spread to nearby organs.
    • Stage IIC: Cancer has spread through the serosa (outermost layer) of the rectum wall to nearby organs.

    Stage III

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

    Stage IIIA rectal cancer. Cancer may have spread through the mucosa of the rectum wall to the submucosa and 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 may have spread through the mucosa (innermost layer) of the rectum wall to the submucosa (layer of tissue under the mucosa) and may have spread to the muscle layer of the rectum wall. Cancer has spread to at least one but not more than 3 nearby lymph nodes or cancer cells have formed in tissues near the lymph nodes; or
    • Cancer has spread through the mucosa (innermost layer) of the rectum wall to the submucosa (layer of tissue under the mucosa). Cancer has spread to at least 4 but not more than 6 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 but not to nearby organs. Cancer has spread to at least one but not more than 3 nearby lymph nodes or cancer cells have formed in tissues near the lymph nodes; or
    • Cancer has spread to the muscle layer of the rectum wall or to the serosa (outermost layer) of the rectum wall. Cancer has spread to at least 4 but not more than 6 nearby lymph nodes; or
    • Cancer has spread through the mucosa (innermost layer) of the rectum wall to the submucosa (layer of tissue under the mucosa) and may have spread to the muscle layer of the rectum wall. Cancer has spread to 7 or more nearby lymph nodes.

    In stage IIIC:

    • Cancer has spread through the serosa (outermost layer) of the rectum wall but has not spread to nearby organs. Cancer has spread to at least 4 but not more than 6 nearby lymph nodes; or
    • 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 but has not spread to nearby organs. Cancer has spread to 7 or more nearby lymph nodes; or
    • Cancer has spread through the serosa (outermost layer) of the rectum wall and has spread to nearby organs. Cancer has spread to one or more nearby lymph nodes or cancer cells have formed in tissues near the lymph nodes.

    Stage IV

    Stage IV rectal cancer is divided into stage IVA and stage IVB.

    • Stage IVA: Cancer may have spread through the rectum wall and may have spread to nearby organs or lymph nodes. Cancer has spread to one organ that is not near the rectum, such as the liver, lung, or ovary, or to a distant lymph node.
    • Stage IVB: Cancer may have spread through the rectum wall and may have spread to nearby organs or lymph nodes. Cancer has spread to more than one organ that is not near the rectum or into the lining of the abdominal wall.

    Recurrent 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.

    Treatment for Rectal Cancer

    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.

    Four types of standard 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);

    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 or chemotherapy may be given before surgery to shrink the tumor, make it easier to remove the cancer, and lessen problems with bowel control after surgery. Treatment given before surgery is called neoadjuvant therapy. Even if all the cancer that can be seen at the time of the operation is removed, some patients may be given radiation therapy 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. 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.

    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.

    Targeted therapy

    Targeted therapy is a type of treatment that uses drugs or other substances to identify and attack specific cancer cells without harming normal cells.

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

  • Monoclonal antibodies: Monoclonal antibody therapy is a type of targeted therapy being used for the treatment of rectal cancer. Monoclonal antibody therapy uses antibodies made in the laboratory from a single type of immune system cell. These antibodies can identify substances on cancer cells or normal substances that may help cancer cells grow. The antibodies attach to the substances and 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:

  • Vascular endothelial growth factor (VEGF) inhibitor therapy: Cancer cells make a substance called VEGF, which causes new blood vessels to form (angiogenesis) and helps the cancer grow. VEGF inhibitors block VEGF and stop new blood vessels from forming. This may kill cancer cells because they need new blood vessels to grow. Bevacizumab and ramucirumab are VEGF inhibitors and angiogenesis inhibitors.
  • Epidermal growth factor receptor (EGFR) inhibitor therapy: EGFRs are proteins found on the surface of certain cells, including cancer cells. Epidermal growth factor attaches to the EGFR on the surface of the cell and causes the cells to grow and divide. EGFR inhibitors block the receptor and stop the epidermal growth factor from attaching to the cancer cell. This stops the cancer cell from growing and dividing. Cetuximab and panitumumab are EGFR inhibitors.
  • Immune checkpoint inhibitor therapy: PD-1 is a protein on the surface of T cells that helps keep the body’s immune responses in check. When PD-1 attaches to another protein called PDL-1 on a cancer cell, it stops the T cell from killing the cancer cell. PD-1 inhibitors attach to PDL-1 and allow the T cells to kill cancer cells. Pembrolizumab is a type of immune checkpoint inhibitor.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.
  • 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. This is sometimes called re-staging.

    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 Options by Stage

    Stage 0 (Carcinoma in Situ)

    Treatment of stage 0 may include the following:

    • Simple polypectomy.
    • Local excision.
    • Resection (when the tumor is too large to remove by local excision).

    Stage I Rectal Cancer

    Treatment of stage I rectal cancer may include the following:

    • Local excision.
    • Resection.
    • Resection with radiation therapy and chemotherapy before or after surgery.

    Stages II and III Rectal Cancer

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

  • Surgery.
  • Chemotherapy combined with radiation therapy, followed by surgery.
  • Short-course radiation therapy followed by surgery and chemotherapy.
  • Resection followed by chemotherapy combined with radiation therapy.
  • Chemotherapy combined with radiation therapy, followed by active surveillance. Surgery may be done if the cancer recurs (comes back).
  • A clinical trial of a new treatment.
  • Stage IV and Recurrent Rectal Cancer

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

  • Surgery with or without chemotherapy or radiation therapy.
  • Systemic chemotherapy with or without targeted therapy (a monoclonal antibody or angiogenesis inhibitor).
  • Chemotherapy to control the growth of the tumor.
  • Radiation therapy, chemotherapy, or a combination of both, as palliative therapy to relieve symptoms and improve the quality of life.
  • Placement of a stent to help keep the rectum open if it is partly blocked by the tumor, as palliative therapy to relieve symptoms and improve the quality of life.
  • A clinical trial of a new anticancer drug.
  • Treatment of rectal cancer that has spread to other organs depends on which organ the cancer has spread to.

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

    Updated: June 8, 2018


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