Colorectal CancerLast Updated: January 11, 2012 This section has been reviewed and approved by the Cancer.Net Editorial Board, 12/11 Overview
Colorectal cancer begins when normal cells in the lining of the colon or rectum change and grow uncontrollably, forming a mass called a tumor. A tumor can be benign (noncancerous) or malignant (cancerous, meaning it can spread to other parts of the body). These changes usually take years to develop; however, when a person has an uncommon inherited syndrome, changes can occur within months to years. Both genetic and environmental factors can cause the changes. Anatomy of the colon and rectum The colon and rectum make up the large intestine, which plays an important role in the body's ability to process waste. The colon makes up the first five to six feet of the large intestine, and the rectum makes up the last six inches, ending at the anus. The colon has four sections. The ascending colon is the portion that extends from a pouch called the cecum (the beginning of the large intestine into which the small intestine empties) on the right side of the abdomen. The transverse colon crosses the top of the abdomen. The descending colon takes waste down the left side. Finally, the sigmoid colon at the bottom takes waste a few more inches, down to the rectum. Waste leaves the body through the anus. About colorectal polyps Colorectal cancer most often begins as a polyp, a noncancerous growth that may develop on the inner wall of the colon or rectum as people get older. If not treated or removed, a polyp can become a potentially life-threatening cancer. Recognizing and removing precancerous polyps can prevent colorectal cancer. There are several forms of polyps. Adenomatous polyps, or adenomas, are growths that may become cancerous and can be detected with a colonoscopy (see Risk Factors and Prevention). Polyps are most easily found during colonoscopy because they usually bulge into the colon, forming a mound on the wall of the colon that can be found by the doctor. About 10% of colon polyps are flat and hard to find with a colonoscopy, unless a dye is used to highlight them. These flat polyps have a high risk of becoming cancerous, regardless of their size. Types of colorectal cancer Colorectal cancer can begin in either the colon or the rectum. Cancer that begins in the colon is called colon cancer, and cancer that begins in the rectum is called rectal cancer. Most colon and rectal cancers are a type of tumor called adenocarcinoma, which is cancer of the cells that line the inside tissue of the colon and rectum. This section specifically covers adenocarcinoma. Other types of cancer that occur far less often but can begin in the colon or rectum include carcinoid tumor, gastrointestinal stromal tumor (GIST), and lymphoma. Find out more about basic cancer terms used in this section. Looking for More of an Overview? If you would like additional introductory information, explore these related items on Cancer.Net:
Or, choose “Next” (below, right) to continue reading this detailed section. To select a specific topic within this section, use the icon panel located on the right side of your screen. Statistics
Colorectal cancer is the third most common cancer among both men and women in the United States. It is also the third most common cause of cancer death among men and women separately (and the second most common cause of cancer death total in men and women combined) in the United States. This year, an estimated 143,460 adults in the United States will be diagnosed with colorectal cancer. These numbers include 103,170 new cases of colon cancer and 40,290 new cases of rectal cancer. It is estimated that 51,690 deaths (26,470 men and 25,220 women) will occur. When colorectal cancer is found early, it can often be cured. The death rate from this type of cancer has been declining for most of the past 20 years, possibly because it is usually diagnosed earlier now and treatments have improved. Survival rates for colorectal cancer can vary based on a variety of factors, particularly the stage. If the cancer is found at an early, localized stage, the five-year survival rate (the percentage of people who survive at least five years after the cancer is detected, excluding those who die from other diseases) for people with colorectal cancer is 90%. If the cancer has spread to nearby lymph nodes or organs, the five-year survival rate is 69%. If the cancer has spread to distant parts of the body, the five-year survival rate is 12%. However, for patients who have just one or a few tumors that have spread from the colon to the lung or liver, surgical removal of these tumors can eliminate the cancer, which greatly improves the five-year survival rate for these patients. Cancer survival statistics should be interpreted with caution. These estimates are based on data from thousands of people with this type of cancer in the United States each year, but the actual risk for a particular individual may differ. It is not possible to tell a person how long he or she will live with colorectal cancer. Because the survival statistics are measured in five-year intervals, they may not represent advances made in the treatment or diagnosis of this cancer. Learn more about understanding statistics. Statistics adapted from the American Cancer Society's publication, Cancer Facts & Figures 2012. Medical Illustrations
Risk Factors and Prevention
A risk factor is anything that increases a person’s chance of developing cancer. Although risk factors can influence the development of cancer, most do not directly cause cancer. Some people with several risk factors never develop cancer, while others with no known risk factors do. However, knowing your risk factors and talking about them with your doctor may help you make more informed lifestyle and health care choices. The cause of colorectal cancer is not known, but certain factors appear to increase the risk of developing the disease. The following factors may raise a person’s risk of developing colorectal cancer: Age. The risk of colorectal cancer increases as people get older. Colorectal cancer can occur in young adults and teenagers, but more than 90% of colorectal cancers occur in people older than 50. The average age of diagnosis in the United States is 72. Family history of cancer. Colorectal cancer is more likely to develop in a person who has had a parent, sibling, or child with colorectal cancer, particularly if the family member was diagnosed with colorectal cancer before age 60. Members of families with certain uncommon inherited conditions also have a significant increased risk of colorectal cancer; these include familial adenomatous polyposis (FAP), attenuated familial adenomatous polyposis (AFAP), Gardner syndrome, hereditary nonpolyposis colorectal cancer (HNPCC), Juvenile Polyposis syndrome (JPS), Muir-Torre syndrome, MYH-associated polyposis (MAP), Peutz-Jeghers syndrome (PJS), and Turcot syndrome. Relatives of women with uterine cancer may also be at higher risk. Learn more about the genetics of colorectal cancer. Inflammatory bowel disease (IBD). People with IBD, such as ulcerative colitis or Crohn’s disease, may develop chronic inflammation of the large intestine, which increases the risk of colon cancer. IBD is not the same as irritable bowel syndrome. Adenomatous polyps (adenomas). Polyps are not cancer, but some types of polyps called adenomas are most likely to develop into colorectal cancer. Polyps can often be completely removed using a tool during a colonoscopy, a test in which a doctor looks through a lighted tube into the colon after the patient has been sedated. Polyp removal can prevent colon cancer. People who have had adenomas have a greater risk of additional polyps and of colon cancer, and they should have follow-up screening tests regularly (see below). Personal history of certain types of cancer. People with a personal history of colon cancer and women who have had ovarian cancer or uterine cancer are more likely to develop colon cancer. Race. Black people have the highest rates of sporadic (non-hereditary) colorectal cancer in the United States, and colon cancer is a leading cause of cancer-related deaths among black people. Black women are more likely to die from colorectal cancer than women from any other racial group, and black men are even more likely to die from colorectal cancer than black women. The reasons for these differences are unclear. Noting that black people are more likely to be diagnosed with colon cancer at a younger age, the American College of Gastroenterology suggests that black people begin screening with colonoscopies at age 45 (see below). Earlier screening may find changes in the colon at a more treatable stage. Physical inactivity and obesity. People who lead an inactive lifestyle (no regular exercise and a lot of sitting) and people who are overweight may have an increased risk of colorectal cancer. Smoking. Recent studies have shown that smokers are more likely to die from colorectal cancer than nonsmokers. The following may lower a person’s risk of colorectal cancer: Nonsteroidal anti-inflammatory drugs (NSAIDs). Some studies suggest that aspirin and other NSAIDs may reduce the development of polyps in people with a history of colorectal cancer or polyps. However, regular use of NSAIDs may cause major side effects, including bleeding of the stomach lining and blood clots leading to stroke or heart attack. Taking aspirin or other NSAIDs cannot be substituted for regular colorectal cancer screening. People should talk with their doctor about the risks and benefits of taking aspirin on a regular basis. Diet and supplements. A diet rich in fruits and vegetables and low in red meat may help reduce the risk of colon cancer. Some studies have also found that people who take calcium and vitamin D supplements have a lower risk of colorectal cancer. Screening and Prevention Colorectal cancer can often be prevented through regular screening, which can find precancerous polyps. Talk with your doctor about when screening should begin based on your age and family history of the disease. Although some people should be screened earlier, people of average risk should begin screening at age 50, and black people should start at age 45 (because they are more commonly diagnosed at a younger age). Because most colorectal cancer occurs without symptoms until the disease is advanced, it is important for people to talk with their doctor about the pros and cons of each screening test and how often each test should be given. Under these guidelines, people should begin colorectal cancer screening earlier and/or undergo screening more often if they have any of the following colorectal cancer risk factors:
The tests used to screen for colorectal cancer are described below: Colonoscopy. This test allows the doctor to look inside the entire rectum and colon while a patient is sedated. A colonoscope (a flexible, lighted tube) is inserted into the rectum and the entire colon to look for polyps or cancer. During this procedure, a doctor can remove polyps or other tissue for examination (see biopsy in the Diagnosis section). This is the only screening test that allows the removal of polyps, which can also prevent colorectal cancer. Computed tomography (CT or CAT) scan. CT colonography (sometimes called virtual colonoscopy) is a screening method being studied in some centers. It requires interpretation by a skilled radiologist (a doctor who specializes in obtaining and interpreting medical images) to be used to the best advantage. However, it may be an alternative for people who cannot have a standard colonoscopy due to the risk of anesthesia or if a person has an obstruction in the colon that prevents a full examination. Sigmoidoscopy. A sigmoidoscope (a flexible, lighted tube) is inserted into the rectum and lower colon to check for polyps, cancer, and other abnormalities. During this procedure, a doctor can remove polyps or other tissue for later examination. The doctor cannot check the upper part of the colon (ascending and transverse colon) with this test. If polyps or cancer is found using this test, a colonoscopy to view the entire colon is recommended. Fecal occult blood test (FOBT). This is a test used to find blood in the feces (stool), which can be a sign of polyps or cancer. A positive FOBT test (meaning that blood is found) can be from causes other than a colon polyp or cancer, including bleeding in the stomach or upper GI tract and even ingestion of rare meat or other foods. There are two types of tests: guaiac and immunochemical. Polyps and cancers do not bleed continually, so the FOBT must be done on several stool samples each year and should be repeated each year. Even then, the reduction in deaths from colorectal cancer is fairly small (around 30% if done yearly and 18% if done every other year). Double contrast barium enema (DCBE). For patients who cannot have a colonoscopy, an enema containing barium is given, which helps the outline of the colon and rectum stand out on x-rays. A series of x-rays is then taken of the colon and rectum. In general practice, most doctors would recommend other screening tests because a barium enema has a lower likelihood of detecting precancerous polyps than a colonoscopy, sigmoidoscopy, or CT colonography. Stool DNA tests. This test analyzes the DNA from a person’s stool sample to look for cancer. It uses changes in the DNA that occur in polyps and cancers to determine whether a colonoscopy should be done. Recommendations Different organizations have made different recommendations for colorectal cancer screening. Talk with your doctor about the best test and time between tests based on your health history and personal cancer risk. The American Gastroenterological Association, the American College of Gastroenterology, the American Society for Gastrointestinal Endoscopy, the American Cancer Society, and the American College of Radiology have developed consensus guidelines for screening for colorectal cancer, with the goal of cancer prevention. Beginning at age 50, both men and women of average risk should follow one of these testing schedules. The following tests detect both polyps and cancer:
These tests primarily detect cancer:
The U.S. Preventive Health Services Task Force (USPSTF) also has guidelines for colon cancer screening, which differ somewhat from those mentioned above. The USPSTF recommends one of the following testing methods:
In addition, this task force did not think there was enough evidence of benefit or harm to recommend virtual colonography and fecal DNA testing. According to the USPSTF, adults between ages 76 and 85 should not have routine screening, because the risks outweigh the benefits, and adults older than 85 can forgo colorectal cancer screening. It is important to note that, regardless of the screening test and schedule, any test that indicates an abnormality should be followed up with a colonoscopy. Symptoms and Signs
By being alert to the symptoms of colorectal cancer, it may be possible to detect the disease early, when it is most likely to be treated successfully. However, many people with colorectal cancer do not have any symptoms until the disease is advanced, so people need to be screened regularly. People with colorectal cancer may experience the following symptoms or signs. It is also possible that these symptoms may be caused by a medical condition that is not cancer, especially for the general symptoms of abdominal discomfort, bloating, and irregular bowel movements.
Talk with your doctor if these symptoms last for several weeks or become more severe. And talk with your doctor if you are concerned about any symptom or sign on this list and ask to schedule a colonoscopy to find the underlying reason(s). Since colon cancer can occur in people younger than the recommended screening age and in older people between screenings, anyone at any age who experiences these symptoms should be evaluated by a doctor, to determine if he/she should have a colonoscopy. Your doctor will ask you questions about the symptoms you are experiencing to help find out the cause of the problem, called a diagnosis. This may include how long you’ve been experiencing the symptom(s) and how often. If cancer is diagnosed, relieving symptoms and side effects remains an important part of cancer care and treatment. This may also be called symptom management, palliative care, or supportive care. Be sure to talk with your health care team about symptoms you experience, including any new symptoms or a change in symptoms. Diagnosis
Doctors use many tests to diagnose cancer and to find out if it has metastasized (spread). Some tests may also determine which treatments may be the most effective. For most types of cancer, a biopsy is the only way to make a definitive diagnosis of cancer. If a biopsy is not possible, the doctor may suggest other tests that will help make a diagnosis. Imaging tests may be used to find out whether the cancer has metastasized. Your doctor may consider these factors when choosing a diagnostic test:
In addition to a physical examination, the following tests may be used to diagnose colorectal cancer. The doctor will also ask about the person's medical and family history. Colonoscopy. As described in Screening, this test allows the doctor to look inside the entire rectum and colon while a patient is sedated. A colonoscopist is a doctor who specializes in performing this test. If colorectal cancer is present, a complete diagnosis that accurately describes the location and spread of the cancer may not be possible until the tumor is surgically removed. Biopsy. A biopsy is the removal of a small amount of tissue for examination under a microscope. Other tests can suggest that cancer is present, but only a biopsy can make a definite diagnosis of colorectal cancer. The sample removed from the biopsy is analyzed by a pathologist (a doctor who specializes in interpreting laboratory tests and evaluating cells, tissues, and organs to diagnose disease). A biopsy may be performed during a colonoscopy, or it may be done on any tissue that is removed during surgery. Sometimes, a CT scan or ultrasound is used to perform a needle biopsy (removing tissue through the skin with a needle that is guided into the tumor). Blood tests. Because colorectal cancer often bleeds into the large intestine or rectum, people with the disease may become anemic. A test of the number of red cells in the blood, which is part of a complete blood count (CBC), can indicate that bleeding may be occurring. Another blood test detects the levels of a protein called carcinoembryonic antigen (CEA). High levels of CEA may indicate that a cancer has spread to other parts of the body. CEA is not an absolute test for colorectal cancer because levels are high for only about 60% of people with colorectal cancer that has spread to other organs from the colon. In addition, other medical conditions can cause CEA to increase. CEA tests are most often used to monitor colorectal cancer for patients already receiving treatment and are not screening tests. Learn more about tumor markers for colorectal cancer. CT scan. A CT scan creates a three-dimensional picture of the inside of the body with an x-ray machine. A computer then combines these images into a detailed, cross-sectional view that shows any abnormalities or tumors. Sometimes, a contrast medium (a special dye) is injected into a patient’s vein to provide better detail. In a person with colon cancer, a CT scan can check for the spread of cancer in the lungs, liver, and other organs. It is often done before surgery (see Treatment). Magnetic resonance imaging (MRI). An MRI uses magnetic fields, not x-rays, to produce detailed images of the body. A contrast medium (a special dye) may be injected into a patient’s vein to create a clearer picture. MRI is the best imaging test to find where the colorectal cancer has grown. Ultrasound. Ultrasound is a procedure that uses sound waves to create a picture of the internal organs to tell if cancer has spread. Endorectal ultrasound is commonly used to find out how deeply the rectal cancer has grown and can be used to help plan treatment; however, this test cannot accurately detect metastatic lymph nodes (cancer that has spread to nearby lymph nodes) or cancer that has spread beyond the pelvis. Ultrasound can also be used to view the liver, although CT scans or MRIs (see above) are preferred because they are better for finding tumors in the liver. Chest x-ray. An x-ray is a way to create a picture of the structures inside of your body, using a small amount of radiation. An x-ray of the chest can help doctors find out if the cancer has spread to the lungs. Positron emission tomography (PET) scan. A PET scan is a way to create pictures of organs and tissues inside the body. A small amount of a radioactive substance is injected into a patient’s body. This substance is absorbed mainly by organs and tissues that use the most energy. Because cancer tends to use energy actively, it absorbs more of the radioactive substance. A scanner then detects this substance to produce images of the inside of the body. Learn more about what to expect when having common tests, procedures, and scans. After these diagnostic tests are done, your doctor will review all of the results with you. If the diagnosis is cancer, these results also help the doctor describe the cancer; this is called staging. Learn more about the first steps to take after a diagnosis of cancer. Staging With Illustrations
Staging is a way of describing a cancer, such as where it is located, if or where it has spread, and whether it is affecting the functions of other organs in the body. Doctors use diagnostic tests to determine the cancer's stage, so staging may not be complete until all of the tests are finished. Knowing the stage helps the doctor to decide what kind of treatment is best and can help predict a patient's prognosis (chance of recovery). There are different stage descriptions for different types of cancer. One tool that doctors use to describe the stage is the TNM system. This system judges three factors: the tumor itself, the lymph nodes around the tumor, and if the tumor has spread to other parts of the body. The results are combined to determine the stage of cancer for each person. There are five stages: stage 0 (zero) and stages I through IV (one through four). The stage provides a common way of describing the cancer, so doctors can work together to plan the best treatments. TNM is an abbreviation for tumor (T), node (N), and metastasis (M). Doctors look at these three factors to determine the stage of cancer:
Tumor. Using the TNM system, the "T" plus a letter or number (0 to 4) is used to describe how deeply the primary tumor has grown into the bowel lining. Some stages are also divided into smaller groups that help describe the tumor in even more detail. Specific tumor information is listed below. TX: The primary tumor cannot be evaluated. T0: There is no evidence of cancer in the colon or rectum. Tis: Refers to carcinoma in situ (also called cancer in situ). Cancer cells are found only in the epithelium or lamina propria (the top layers lining the inside of the colon or rectum). T1: The tumor has grown into the submucosa (the layer of tissue underneath the mucosa or lining of the colon). T2: The tumor has grown into the muscularis propria (a deeper, thick layer of muscle that contracts to force the contents of the intestines along). T3: The tumor has grown through the muscularis propria and into the subserosa (a thin layer of connective tissue beneath the outer layer of some parts of the large intestine) or into tissues surrounding the colon or rectum. T4a: The tumor has grown into the surface of the visceral peritoneum (through all layers of the colon). T4b: The tumor directly has grown into or has attached to other organs or structures. Node. The "N" in the TNM system stands for lymph nodes. The lymph nodes are tiny, bean-shaped organs that are located throughout the body that help the body fight infections as part of the body's immune system. There are regional lymph nodes (lymph nodes near the colon and rectum). All others are distant lymph nodes (lymph nodes found in other parts of the body). NX: The regional lymph nodes cannot be evaluated. N0: There is no spread to regional lymph nodes. N1a: There are tumor cells found in one regional lymph node. N1b: There are tumor cells found in two to three regional lymph nodes. N1c: There are nodules made up of tumor cells found in the structures near the colon that do not appear to be lymph nodes. N2a: There are tumor cells found in four to six regional lymph nodes. N2b: There are tumor cells found in seven or more regional lymph nodes. Distant metastasis. The "M" in the TNM system describes cancer that has spread to other parts of the body (such as the liver or lungs). MX: Distant metastasis cannot be evaluated. M0: The disease has not spread to a distant part of the body. M1a: The cancer has spread to one other part of the body beyond the colon or rectum. M1b: The cancer has spread to more than one part of the body other than the colon or rectum. Cancer stage grouping Doctors assign the stage of the cancer by combining the T, N, and M classifications. Stage 0: This is called cancer in situ. The cancer cells are only in the mucosa (the inner lining) of the colon or rectum.
Stage I: The cancer has grown through the mucosa and has invaded the muscular layer of the colon or rectum. It has not spread into nearby tissue or lymph nodes (T1 or T2, N0, M0).
Stage IIA: The cancer has grown through the wall of the colon or rectum and has not spread to nearby tissue or to the nearby lymph nodes (T3, N0, M0).
Stage IIB: The cancer has grown through the layers of the muscle to the lining of the abdomen (called the visceral peritoneum). It has not spread to the nearby lymph nodes or elsewhere (T4a, N0, M0).
Stage IIC: The tumor has spread through the wall of the colon or rectum and has grown into nearby structures. It has not spread to the nearby lymph nodes or elsewhere (T4b, N0, M0).
Stage IIIA: The cancer has grown through the inner lining or into the muscle layers of the intestine and spread to one to three lymph nodes, or to a nodule of tumor in tissues around the colon or rectum that do not appear to be lymph nodes but has not spread to other parts of the body (T1 or T2; N1 or N1c, M0 or T1, N2a, M0).
Stage IIIB: The cancer has grown through the bowel wall or to surrounding organs and into one to three lymph nodes or to a nodule of tumor in tissues around the colon or rectum that do not appear to be lymph nodes, but has not spread to other parts of the body (T3 or T4a, N1 or N1c, M0; T2 or T3, N2a, M0; or T1 or T2, N2b, M0).
Stage IIIC: The cancer of the colon, regardless of how deep it has grown, has spread to four or more lymph nodes, but not to other distant parts of the body (T4a, N2a, M0; T3 or T4a, N2b, M0; or T4b, N1 or N2, M0).
Stage IVA: The cancer has spread to a single distant part of the body, such as the liver or lungs (any T, any N, M1a).
Stage IVB: The cancer has spread to more than one part of the body (any T, any N, M1b).
Recurrent: Recurrent cancer is cancer that has come back after treatment. The disease may be found in the colon, rectum, or in another part of the body. If there is a recurrence, the cancer may need to be staged again (re-staging) using the system above. Tumor grade. Doctors may also use the term "grade," which describes how much the tumor appears like normal tissue. The grade of a cancer can help the doctor predict how quickly the cancer might grow. In cancer that resembles normal tissue, doctors can clearly see different types of cells grouped together. In a higher-grade cancer, the cancer cells usually look less like normal cells, or "wilder"). In general, a lower-grade cancer means a better prognosis. GX: The tumor grade cannot be identified. G1: The cells are more like normal cells (called well differentiated). G2: The cells are somewhat like normal cells (called moderately differentiated). G3: The cells look less like normal cells (called poorly differentiated). G4: The cells barely look like normal cells (called undifferentiated). Used with permission of the American Joint Committee on Cancer (AJCC), Chicago, Illinois. The original source for this material is the AJCC Cancer Staging Manual, Seventh Edition (2010) published by Springer-Verlag New York, www.cancerstaging.net. Treatment
This section outlines treatments that are the standard of care (the best proven treatments available) for colorectal cancer. When making treatment plan decisions, patients are also encouraged to consider clinical trials as an option. A clinical trial is a research study to test a new treatment to evaluate whether it is safe, effective, and possibly better than standard treatment. Your doctor can help you review all treatment options. For more information, visit the Clinical Trials and Current Research sections. Treatment overview In cancer care, different types of doctors often work together to create a patient’s overall treatment plan that combines different types of treatments. This is called a multidisciplinary team. For colorectal cancer, this often includes a gastroenterologist (a doctor who specializes in the function and disorders of the gastrointestinal tract), surgeon, medical oncologist, and radiation oncologist. Descriptions of the most common treatment options for colorectal cancer are listed below, followed by a brief outline of treatment options listed by stage. Treatment options and recommendations depend on several factors, including the type and stage of cancer, possible side effects, and the patient’s preferences and overall health. Learn more about making treatment decisions. Surgery Surgery is the removal of the tumor and surrounding tissue during an operation. This is the most common treatment for colorectal cancer and is often called surgical resection. Part of the healthy colon or rectum and nearby lymph nodes will also be removed. While both general surgeons and specialists may perform colorectal surgery, many people talk with specialists who have additional training and experience in colorectal surgery. A surgical oncologist is a doctor who specializes in treating cancer using surgery, and a colorectal surgeon has additional training beyond education in general surgery. Some patients may be able to have laparoscopic colorectal cancer surgery. With this technique, several viewing scopes are passed into the abdomen while a patient is under anesthesia. The incisions are smaller and the recovery time is often shorter than with standard colon surgery. Laparoscopic surgery is as effective as conventional colon surgery in removing the cancer. Surgeons who perform laparoscopic surgery have been specially trained in that technique. Less often, a person with rectal cancer may need to have a colostomy. This is a surgical opening, or stoma, through which the colon is connected to the abdominal surface to provide a pathway for waste to exit the body; such waste is collected in a pouch worn by the patient. Sometimes, the colostomy is only temporary to allow the rectum to heal, but it may be permanent. With modern surgical techniques and the use of radiation therapy and chemotherapy before surgery when needed, most people treated for rectal cancer do not need a permanent colostomy. Learn more about colostomies. Some patients may be able to have surgery on the liver or lungs to remove tumors that have spread to those organs. Another way is to use energy in the form of radiofrequency waves to heat the tumors (called radiofrequency ablation or RFA). Not all liver or lung tumors can be treated with this approach. Sometimes, RFA can be done through the skin or during surgery. While this can preserve the liver and lung tissue that might be removed in a regular surgical resection, there is also a chance that parts of tumor will be left behind. In general, the side effects of surgery include pain and tenderness in the area of the operation. The operation may also cause constipation or diarrhea, which usually goes away after a while. People who have a colostomy may have irritation around the stoma. The doctor, nurse, or a specialist in colostomy management (called an enterostomal therapist) can teach the patient how to clean the area and prevent infection. Many people need to retrain their bowel after surgery, which may take some time and assistance. People should talk with their doctor if they do not regain good control of bowel function. Learn more about cancer surgery. Radiation therapy Radiation therapy is the use of high-energy x-rays to kill cancer cells and is commonly used for treating rectal cancer because this tumor tends to recur near where it originally started. A doctor who specializes in giving radiation therapy to treat cancer is called a radiation oncologist. A radiation therapy regimen (schedule) usually consists of a specific number of treatments given over a set period of time. External-beam radiation therapy uses a machine to deliver x-rays to where the cancer is located. Radiation treatment is usually given five days a week for several weeks and may be given in the doctor's office or at the hospital. For some people, specialized radiation therapy techniques, such as intraoperative radiation therapy (a high, single dose of radiation therapy given during surgery) or brachytherapy (placing radioactive "seeds" inside the body), may help get rid of small areas of tumor that could not be removed during surgery. In one type of brachytherapy with a product called SIR-Spheres, tiny amounts of yttrium-90 (a radioactive substance) are injected into the liver to treat colorectal cancer that has spread to the liver when surgery is not an option. While limited information is available about how effective this approach is, some studies suggest that it may help slow the growth of cancer cells. For rectal cancer, radiation therapy may be used before surgery (called neoadjuvant therapy) to shrink the tumor so that it is easier to remove or after surgery to destroy any remaining cancer cells, as both have worked to treat this disease. Chemotherapy is often given at the same time as radiation therapy (called chemoradiation therapy) to increase the effectiveness of the radiation therapy. Chemoradiation therapy is often used in rectal cancer before surgery to avoid colostomy or reduce the chance that the cancer will recur. One recent study found that radiation therapy plus chemotherapy before surgery worked better than the same radiation therapy and chemotherapy given after surgery. The main benefits included a lower rate of the tumor coming back in the area where it started, fewer patients that needed permanent colostomies, and fewer problems with scarring of the bowel in the area where the radiation therapy was given. Side effects from radiation therapy may include fatigue, mild skin reactions, upset stomach, and loose bowel movements. It may also cause bloody stools (bleeding through the rectum) or blockage of the bowel. Most side effects go away soon after treatment is finished. Sexual problems, as well as infertility (the inability to have a child) in both men and women, may occur after radiation therapy to the pelvis. Before treatment begins, talk with your doctor about the possible sexual and fertility-related side effects of your treatment and the available options for preserving fertility. Learn more about radiation therapy. Chemotherapy Chemotherapy is the use of drugs to kill cancer cells, usually by stopping the cancer cells’ ability to grow and divide. Systemic chemotherapy is delivered through the bloodstream to reach cancer cells throughout the body. Chemotherapy is usually given by a medical oncologist, a doctor who specializes in treating cancer with medication. A chemotherapy regimen (schedule) usually consists of a specific number of cycles given over a set period of time. Chemotherapy for colorectal cancer is usually injected directly into a vein, although some chemotherapy can be given as a pill. A patient may receive one drug at a time or combinations of different drugs at the same time. Chemotherapy may be given after surgery to eliminate any remaining cancer cells. For some people with rectal cancer, the doctor will give chemotherapy and radiation therapy before surgery to reduce the size of a rectal tumor and reduce the chance of cancer returning. Currently, seven drugs are approved by the U.S. Food and Drug Administration (FDA) to treat colorectal cancer in the United States. Your doctor may recommend one or several of them at different times during treatment. These drugs are fluorouracil (5-FU, Adrucil), capecitabine (Xeloda), irinotecan (Camptosar), oxaliplatin (Eloxatin), bevacizumab (Avastin), cetuximab (Erbitux), and panitumumab (Vectibix). (These last three are described under “Targeted therapy” below.) Some common treatments are:
Chemotherapy may cause vomiting, nausea, diarrhea, or mouth sores. However, medications to prevent these side effects are available. Because of the way drugs are given, these side effects are less severe than they have been in the past for most patients. In addition, patients may be unusually tired, and there is an increased risk of infection. Neuropathy (tingling or numbness in feet or hands) may also occur with some drugs. Hair loss is an uncommon side effect with the drugs used to treat colorectal cancer. Medications are available to ease most side effects, including nausea, neuropathy, and diarrhea. If side effects are particularly difficult, the dose of drug may be lowered or a treatment session may be postponed. Patients should talk with their health care team to understand when to call their doctor about side effects. Read more about managing side effects. The side effects from chemotherapy usually go away once treatment is finished. Learn more about chemotherapy and preparing for treatment. The medications used to treat cancer are continually being evaluated. Talking with your doctor is often the best way to learn about the medications prescribed for you, their purpose, and their potential side effects or interactions with other medications. Learn more about your prescriptions by using searchable drug databases. Targeted therapy Targeted therapy is a treatment that targets the cancer’s specific genes, proteins, or the tissue environment that contributes to cancer growth and survival. This type of treatment blocks the growth and spread of cancer cells while limiting damage to normal cells, usually leading to fewer side effects than other cancer medications. Recent studies show that not all tumors have the same targets. To find the most effective treatment, your doctor may run tests to identify the genes, proteins, and other factors in your tumor. As a result, doctors can better match each patient with the most effective treatment whenever possible. In addition, many research studies are taking place now to find out more about specific molecular targets and new treatments directed at them. These drugs are becoming more important in the treatment of colorectal cancer. Learn more about targeted treatments. Anti-angiogenesis therapy. Anti-angiogenesis therapy is a type of targeted therapy. It is focused on stopping angiogenesis, which is the process of making new blood vessels. Because a tumor needs the nutrients found in blood vessels to grow and spread, the goal of anti-angiogenesis therapies is to “starve” the tumor. Bevacizumab is a type of anti-angiogenesis therapy called a monoclonal antibody. When given with chemotherapy, bevacizumab increases the length of time patients with advanced colorectal cancer live. In 2004, the FDA approved bevacizumab along with chemotherapy for the first-line (first treatment given) treatment of patients with advanced colorectal cancer. Recent studies have shown it is also effective as second-line therapy along with chemotherapy. Epidermal growth factor receptor (EGFR) inhibitors. An EGFR inhibitor is a type of targeted therapy. Researchers have found that drugs that block EGFR may be effective in stopping or slowing the growth of colorectal cancer. Researchers have found that drugs that block EGFR may be effective in shrinking or stabilizing the growth of colorectal cancer. Cetuximab and panitumumab are monoclonal antibodies that block EGFR. Cetuximab is an antibody made from mouse cells that still has some of the mouse structure. Panitumumab is made entirely from human proteins and is less likely to cause an allergic reaction than cetuximab. Recent studies show that cetuximab and panitumumab do not work as well for tumors that have specific mutations (changes) to a gene called KRAS. ASCO released a provisional clinical opinion recommending that all patients with metastatic colorectal cancer who may receive anti-EFGR therapy, such as cetuximab and panitumumab, have their tumors tested for KRAS gene mutations. If a patient’s tumor has a mutated form of the KRAS gene, ASCO recommends against the use of anti-EFGR antibody therapy. Furthermore, the FDA now recommends that both cetuximab and panitumumab only be given to patients with tumors with non-mutated (sometimes called wild type) KRAS genes. Research is underway to determine what role cetuximab and panitumumab might play in patients with metastatic colorectal cancer who’ve had surgery and who have not previously been given chemotherapy. The side effects of targeted treatments include a rash to the face and upper body, which can be prevented or reduced with various treatments. Find out more about skin reactions to targeted therapies. Treatment options by stage Stage 0 colorectal cancer The usual treatment is a polypectomy (removal of a polyp) during a colonoscopy. There is no additional surgery unless the polyp cannot be fully removed. Stage I colorectal cancer Surgical removal of the tumor and lymph nodes is usually the only treatment needed. Stage II colorectal cancer Patients should talk with their doctor about whether more treatment is needed after surgery, as some patients receive adjuvant chemotherapy. This is treatment after surgery with chemotherapy aimed at trying to destroy any remaining cancer cells. However, cure rates for surgery alone are quite good, and there are few benefits of additional treatment for people with this stage of colon cancer. Learn more about adjuvant therapy for stage II colorectal cancer. A clinical trial is also an option after surgery. For patients with rectal cancer, radiation therapy is usually given in combination with chemotherapy, either before or after surgery. Stage III colorectal cancer Treatment usually involves surgical removal of the tumor followed by adjuvant chemotherapy. A clinical trial is also an option. For patients with rectal cancer, radiation therapy may be used along with chemotherapy before or after surgery. Recurrent colorectal cancer Once your treatment is complete and there is a remission (absence of cancer symptoms; also called “no evidence of disease” or NED), talk with your doctor about the possibility of the cancer returning. Many survivors feel worried or anxious that the cancer will come back. Learn more about coping with this fear. If the cancer does return after the original treatment, it is called recurrent cancer. It may come back in the same place (called a local recurrence), nearby (regional recurrence), or in another place (distant recurrence). When this occurs, a cycle of testing will begin again to learn as much as possible about the recurrence. After testing is done, you and your doctor will talk about your treatment options. Often the treatment plan will include the therapies described above (such as surgery, chemotherapy, and radiation therapy) but may be used in a different combination or given at a different pace. Your doctor may also suggest clinical trials that are studying new ways to treat this type of recurrent cancer. Generally, the treatment options for recurrent cancer are the same as those for metastatic cancer (see below) and include surgery, radiation therapy, and chemotherapy. People with recurrent cancer often experience emotions such as disbelief or fear. Patients are encouraged to talk with their health care team about these feelings and ask about support services to help them cope. Learn more about dealing with cancer recurrence. Metastatic (stage IV) colorectal cancer If cancer has spread to another location in the body, it is called metastatic cancer. Colorectal cancer can spread to distant organs, such as the liver, lungs, peritoneum (the tissue lining the abdomen), or a woman’s ovaries. Patients with this diagnosis are encouraged to talk with doctors who are experienced in treating this stage of cancer, because there can be different opinions about the best treatment plan. Learn more about seeking a second opinion before starting treatment, so you are comfortable with the treatment plan chosen. This discussion may include clinical trials. Your health care team may recommend a treatment plan that includes a combination of surgery, radiation therapy, and chemotherapy, which can be used to slow the spread of the disease and often temporarily shrink a cancerous tumor. At this stage, surgery to remove the portion of the colon where the cancer started usually cannot cure the cancer, but it can help relieve blockage of the colon or other complications. Surgery may also be used to remove parts of other organs that contain cancer (called resection) and can cure some people if a limited amount of cancer spreads to a single organ, such as the liver or lung. In colon cancer, if the cancer has spread only to the liver and if surgery is possible–either before or after chemotherapy–the patient has a chance of complete cure. Even when curing the cancer is not possible, surgery may add months or even years to a person’s life. Determining who can benefit from surgery for cancer that has spread to the liver is often a complicated process that involves doctors of multiple specialties working together to plan the best option. In addition to treatment to slow, stop, or eliminate the cancer (also called disease-directed treatment), an important part of cancer care is relieving a person’s symptoms and side effects. It includes supporting the patient with his or her physical, emotional, and social needs, an approach called palliative or supportive care. People often receive disease-directed therapy and treatment to ease symptoms at the same time. Chemotherapy and radiation therapy at this stage can rarely cure cancer, but they may help to relieve pain and other symptoms and lengthen a person’s life. If disease-directed treatment is not successful, this may also be called advanced cancer. This diagnosis is stressful, and it may be difficult to discuss. However, it is important to have open and honest conversations with your doctor and health care team to express your feelings, preferences, and concerns. The health care team is there to help, and many team members have special skills, experience, and knowledge to support patients and their families. Learn more about advanced cancer care planning. Find out more about common terms used during cancer treatment. About Clinical Trials
Doctors and scientists are always looking for better ways to treat patients with colorectal cancer. To make scientific advances, doctors create research studies involving people, called clinical trials. Many clinical trials are focused on new treatments, evaluating whether a new treatment is safe, effective, and possibly better than the current (standard) treatment. These types of studies evaluate new drugs, different combinations of existing treatments, new approaches to radiation therapy or surgery, and new methods of treatment. Patients who participate in clinical trials are often among the first to receive new treatments before they are widely available. However, there is no guarantee that the new treatment will be safe, effective, or better than a standard treatment. There are also clinical trials that study new ways to ease symptoms and side effects during treatment and manage the late effects that may occur after treatment. Talk with your doctor about clinical trials regarding side effects. In addition, there are ongoing studies about ways to prevent the disease. Patients decide to participate in clinical trials for many reasons. For some patients, a clinical trial is the best treatment option available. Because standard treatments are not perfect, patients are often willing to face the added uncertainty of a clinical trial in the hope of a better result. Other patients volunteer for clinical trials because they know that these studies are the only way to make progress in treating colorectal cancer. Even if they do not benefit directly from the clinical trial, their participation may benefit future patients with colorectal cancer. Sometimes people have concerns that, by participating in a clinical trial, they may receive no treatment by being given a placebo or a “sugar pill.” The use of placebos in cancer clinical trials is rare. When a placebo is used in a study, it is done with the full knowledge of the participants. Find out more about placebos in cancer clinical trials. To join a clinical trial, patients must participate in a process known as informed consent. During informed consent, the doctor should list all of the patient’s options, so that the person understands how the new treatment differs from the standard treatment. The doctor must also list all of the risks of the new treatment, which may or may not be different from the risks of standard treatment. Finally, the doctor must explain what will be required of each patient in order to participate in the clinical trial, including the number of doctor visits, tests, and the schedule of treatment. Learn more about clinical trials, including patient safety, phases of a clinical trial, deciding to participate in a clinical trial, questions to ask the research team, and links to find clinical trials. For specific topics being studied for colorectal cancer, learn more in the Current Research section. Patients who participate in a clinical trial may stop participating at any time for any personal or medical reason. This may include that the new treatment is not working or there are serious side effects. It is important that patients participating in a clinical trial talk with their doctor and researchers about who will be providing their treatment and care during the clinical trial, after the clinical trials ends, and/or if the patient chooses to leave the clinical trial before it ends. Side Effects
Cancer and its treatment can cause a variety of side effects. However, doctors have made major strides in recent years in reducing pain, nausea and vomiting, and other physical side effects of cancer treatments. Many treatments used today are less intensive but as effective as treatments used in the past. Doctors also have many ways to provide relief to patients when such side effects occur. Fear of treatment side effects is common after a diagnosis of cancer, but it may be helpful to know that preventing and controlling side effects is a major focus of your health care team. Before treatment begins, talk with your doctor about possible side effects of the specific treatments you will be receiving. The specific side effects that can occur depend on a variety of factors, including the type of cancer, its location, the individual treatment plan (including the length and dosage of treatment), and your overall health. Common side effects for each treatment option are described in detail within the Treatment section. Ask your doctor which side effects are most likely to happen (and which are not), when side effects are likely to occur, and how they will be addressed by the health care. Also, be sure to communicate with the doctor about side effects you experience during and after treatment. Care of a patient’s symptoms and side effects is an important part of a person’s overall treatment plan; this is called palliative or supportive care. It helps people with cancer at any stage of illness be as comfortable as possible. Learn more about the most common side effects of cancer and different treatments, along with ways to prevent or control them. Be sure to talk with your doctor about the level of caregiving you may need during treatment and recovery, as family members and friends often play an important role in the care of a person with colorectal cancer. Learn more about caregiving. In addition to physical side effects, there may be psychosocial (emotional and social) effects as well. For many patients, a diagnosis of colorectal cancer is stressful and can bring difficult emotions. Patients and their families are encouraged to share their feelings with a member of their health care team who can help with coping strategies. Learn more about the importance of addressing such needs, including concerns about managing the cost of your cancer care. A side effect that occurs months or years after treatment is called a late effect. Treatment of late effects is an important part of survivorship care. Learn more about late effects or long-term side effects by reading the After Treatment section or talking with your doctor. After Treatment
After treatment for colorectal cancer ends, talk with your doctor about developing a follow-up care plan. This plan may include regular physical examinations and/or medical tests to monitor your recovery for the coming months and years. Get specific recommendations for follow-up care for colorectal cancer. In addition, ASCO offers cancer treatment summary forms to help keep track of the colorectal cancer treatment you received and develop a survivorship care plan once treatment ends. People recovering from colorectal cancer are encouraged to follow established guidelines for good health, such as maintaining a healthy weight, not smoking, eating a balanced diet, and having recommended cancer screening tests. Talk with your doctor to develop a plan that is best for your needs. Moderate exercise can help rebuild your strength and energy level. Your doctor can help you create a safe exercise plan based upon your needs, physical abilities, and fitness level. Learn more about the next steps to take in survivorship,including making positive lifestyle changes. Current Research
Doctors are working to learn more about colorectal cancer, ways to prevent it, how to best treat it, and how to provide the best care to people diagnosed with this disease. The following areas of research may include new options for patients through clinical trials. Always talk with your doctor about the diagnostic and treatment options best for you. Improved detection methods. Researchers are developing tests to analyze stool samples to find genetic changes associated with colorectal cancer. By finding and removing polyps or identifying cancer early, doctors have a better chance of curing the disease. Tests to predict the risk of cancer recurrence. Tests that analyze various genes important to tumor growth and spread can help doctors and patients make decisions about whether to use chemotherapy after treatment. Researchers hope that these tests can spare people with a lower risk of recurrence from the side effects of additional treatment. Cancer vaccines. Cancer vaccines are a type of immunotherapy (also called biologic therapy). Immunotherapy is designed to boost the body's natural defenses to fight the cancer. It uses materials made either by the body or in a laboratory to bolster, target, or restore immune system function. New drugs. Many new drugs are being tested for colorectal cancer, including advanced colon and rectal cancers. New types of chemotherapy and targeted therapy are being studied. Most are only available through clinical trials. Supportive care. Clinical trials are underway to find better ways of reducing symptoms and side effects of current colorectal cancer treatments in order to improve patients’ comfort and quality of life. Learn more about common statistical terms used in cancer research. Looking for More about Current Research? If you would like additional information about the latest areas of research regarding colorectal cancer, explore these related items:
Or, choose “Next” (below, right) to continue reading this detailed section. Questions to Ask the Doctor
Talking often with the doctor is important to make informed decisions about your health care. These suggested questions are a starting point to help you learn more about your cancer care and treatment. You are also encouraged to ask additional questions that are important to you. General
Before surgery
For rectal cancer
After surgery
Question related to a colostomy (if needed)
Patient Information Resources
In addition to Cancer.Net, there are other sources of information about this type of cancer available online. Cancer.Net maintains a list of national, not-for-profit organizations that may be helpful in finding additional information, services, and support. As always, be sure to talk with your doctor about questions you may have about information you find about this disease. View organizations that offer information on this specific type of cancer. |
