Cancer that begins in the colon is called colon cancer, and cancer that begins in the rectum is called rectal cancer. Cancer that starts in either of these organs may also be called colorectal cancer.
In 2013, about 143,000 people in the United States will be diagnosed with colorectal cancer. It is the fourth most common cancer in men, after skin, prostate, and lung cancer. It is also the fourth most common cancer in women, after skin, breast, and lung cancer.
You will read about possible risk factors, screening, symptoms, diagnosis, and treatment. You will also find lists of questions to ask your doctor. It may help to take this booklet with you to your next appointment.
Cancer begins in cells, the building blocks that make up all tissues and organs of the body, including the breast.
Normal cells in the breast and other parts of the body grow and divide to form new cells as they are needed. When normal cells grow old or get damaged, they die, and new cells take their place. .
Sometimes, this process goes wrong. New cells form when the body doesn’t need them, and old or damaged cells don’t die as they should. The buildup of extra cells often forms a mass of tissue called a lump, growth, or tumor.
Tumors in the breast can be benign (not cancer) or malignant (cancer):
- Are usually not harmful
- Rarely invade the tissues around them
- Don’t spread to other parts of the body
- Can be removed and usually don’t grow back
- May be a threat to life
- Can invade nearby organs and tissues (such as the chest wall)
- Can spread to other parts of the body
- Often can be removed but sometimes grow back
When colorectal cancer spreads outside the colon or rectum, cancer cells are often found in nearby lymph nodes. If cancer cells have reached these nodes, they may also have spread to other lymph nodes or other organs. Colorectal cancer cells most often spread to the liver.
When cancer spreads from its original place to another part of the body, the new tumor has the same kind of abnormal cells and the same name as the original tumor. For example, if colorectal cancer spreads to the liver, the cancer cells in the liver are actually colorectal cancer cells. The disease is metastatic colorectal cancer, not liver cancer. For that reason, it is treated as colorectal cancer, not liver cancer. Doctors call the new tumor “distant” or metastatic disease.
No one knows the exact causes of colorectal cancer. Doctors often cannot explain why one person develops this disease and another does not. However, it is clear that colorectal cancer is not contagious. No one can catch this disease from another person.
Research has shown that people with certain risk factors are more likely than others to develop colorectal cancer. A risk factor is something that may increase the chance of developing a disease.
Studies have found the following risk factors for colorectal cancer:
- Age over 50: Colorectal cancer is more likely to occur as people get older. More than 90 percent of people with this disease are diagnosed after age 50. The average age at diagnosis is 72.
- Colorectal polyps: Polyps are growths on the inner wall of the colon or rectum. They are common in people over age 50. Most polyps are benign (not cancer), but some polyps (adenomas) can become cancer. Finding and removing polyps may reduce the risk of colorectal cancer.
- Family history of colorectal cancer: Close relatives (parents, brothers, sisters, or children) of a person with a history of colorectal cancer are somewhat more likely to develop this disease themselves, especially if the relative had the cancer at a young age. If many close relatives have a history of colorectal cancer, the risk is even greater.
- Genetic alterations: Changes in certain genes increase the risk of colorectal cancer.
- Hereditary nonpolyposis colon cancer (HNPCC) is the most common type of inherited (genetic) colorectal cancer. It accounts for about 2 percent of all colorectal cancer cases. It is caused by changes in an HNPCC gene. Most people with an altered HNPCC gene develop colon cancer, and the average age at diagnosis of colon cancer is 44.
- Familial adenomatous polyposis (FAP) is a rare, inherited condition in which hundreds of polyps form in the colon and rectum. It is caused by a change in a specific gene called APC. Unless FAP is treated, it usually leads to colorectal cancer by age 40. FAP accounts for less than 1 percent of all colorectal cancer cases.
Family members of people who have HNPCC or FAP can have genetic testing to check for specific genetic changes. For those who have changes in their genes, health care providers may suggest ways to try to reduce the risk of colorectal cancer, or to improve the detection of this disease. For adults with FAP, the doctor may recommend an operation to remove all or part of the colon and rectum.
- Personal history of cancer: A person who has already had colorectal cancer may develop colorectal cancer a second time. Also, women with a history of cancer of the ovary, uterus (endometrium), or breast are at a somewhat higher risk of developing colorectal cancer.
- Ulcerative colitis or Crohn disease: A person who has had a condition that causes inflammation of the colon (such as ulcerative colitis or Crohn’s disease) for many years is at increased risk of developing colorectal cancer.
- Diet: Studies suggest that diets high in fat (especially animal fat) and low in calcium, folate, and fiber may increase the risk of colorectal cancer. Also, some studies suggest that people who eat a diet very low in fruits and vegetables may have a higher risk of colorectal cancer. However, results from diet studies do not always agree, and more research is needed to better understand how diet affects the risk of colorectal cancer.
Because people who have colorectal cancer may develop colorectal cancer a second time, it is important to have checkups. If you have colorectal cancer, you also may be concerned that your family members may develop the disease. People who think they may be at risk should talk to their doctor. The doctor may be able to suggest ways to reduce the risk and can plan an appropriate schedule for checkups. See the “Screening” section to learn more about tests that can find polyps or colorectal cancer.
Screening tests help your doctor find polyps or cancer before you have symptoms. Finding and removing polyps may prevent colorectal cancer. Also, treatment for colorectal cancer is more likely to be effective when the disease is found early.
To find polyps or early colorectal cancer:
- People in their 50s and older should be screened.
- People who are at higher-than-average risk of colorectal cancer should talk with their doctor about whether to have screening tests before age 50, what tests to have, the benefits and risks of each test, and how often to schedule appointments.
The following screening tests can be used to detect polyps, cancer, or other abnormal areas.
Your doctor can explain more about each test:
- Fecal occult blood test (FOBT): Sometimes cancers or polyps bleed, and the FOBT can detect tiny amounts of blood in the stool. If this test detects blood, other tests are needed to find the source of the blood. Benign conditions (such as hemorrhoids) also can cause blood in the stool.
- Sigmoidoscopy: Your doctor checks inside your rectum and the lower part of the colon with a lighted tube called a sigmoidoscope. If polyps are found, the doctor removes them. The procedure to remove polyps is called a polypectomy.
- Colonoscopy: Your doctor examines inside the rectum and entire colon using a long, lighted tube called a colonoscope. Your doctor removes polyps that may be found.
- Double-contrast barium enema: You are given an enema with a barium solution, and air is pumped into your rectum. Several x-ray pictures are taken of your colon and rectum. The barium and air help your colon and rectum show up on the pictures. Polyps or tumors may show up.
- Digital rectal exam: A rectal exam is often part of a routine physical examination. Your doctor inserts a lubricated, gloved finger into your rectum to feel for abnormal areas.
- Virtual colonoscopy: This method is under study.
You may find it helpful to read the NCI fact sheet Tests to Detect Colorectal Cancer and Polyps.
You may want to ask your doctor the following questions about screening:
- Which tests do you recommend for me? Why?
- How much do the tests cost? Will my health insurance plan help pay for screening tests?
- Are the tests painful?
- How soon after the tests will I learn the results?
A common symptom of colorectal cancer is a change in bowel habits. Symptoms include:
- Having diarrhea or constipation
- Feeling that your bowel does not empty completely
- Finding blood (either bright red or very dark) in your stool
- Finding your stools are narrower than usual
- Frequently having gas pains or cramps, or feeling full or bloated
- Losing weight with no known reason
- Feeling very tired all the time
- Having nausea or vomiting
Most often, these symptoms are not due to cancer. Other health problems can cause the same symptoms. Anyone with these symptoms should see a doctor to be diagnosed and treated as early as possible.
Usually, early cancer does not cause pain. It is important not to wait to feel pain before seeing a doctor
Women with breast cancer have many treatment options. Treatment options include…
If your physical exam and test results do not suggest cancer, your doctor may decide that no further tests are needed and no treatment is necessary. However, your doctor may recommend a schedule for checkups.
If tests show an abnormal area (such as a polyp), a biopsy to check for cancer cells may be necessary. Often, the abnormal tissue can be removed during colonoscopy or sigmoidoscopy. A pathologist checks the tissue for cancer cells using a microscope.
You may want to ask your doctor these questions before having a biopsy:
- How will the biopsy be done?
- Will I have to go to the hospital for the biopsy?
- How long will it take? Will I be awake? Will it hurt?
- Are there any risks? What are the chances of infection or bleeding after the biopsy?
- How long will it take me to recover? When can I resume a normal diet?
- How soon will I know the results?
- If I do have cancer, who will talk to me about the next steps? When?
If the biopsy shows that cancer is present, your doctor needs to know the extent (stage) of the disease to plan the best treatment. The stage is based on whether the tumor has invaded nearby tissues, whether the cancer has spread and, if so, to what parts of the body.
Your doctor may order some of the following tests:
- Blood tests: Your doctor checks for carcinoembryonic antigen (CEA) and other substances in the blood. Some people who have colorectal cancer or other conditions have a high CEA level.
- Colonoscopy: If colonoscopy was not performed for diagnosis, your doctor checks for abnormal areas along the entire length of the colon and rectum with a colonoscope.
- Endorectal ultrasound: An ultrasound probe is inserted into your rectum. The probe sends out sound waves that people cannot hear. The waves bounce off your rectum and nearby tissues, and a computer uses the echoes to create a picture. The picture may show how deep a rectal tumor has grown or whether the cancer has spread to lymph nodes or other nearby tissues.
- Chest x-ray: X-rays of your chest may show whether cancer has spread to your lungs.
- CT Scan: An x-ray machine linked to a computer takes a series of detailed pictures of areas inside your body. You may receive an injection of dye. A CT scan may show whether cancer has spread to the liver, lungs, or other organs.
Your doctor may also use other tests (such as MRI) to see whether the cancer has spread. Sometimes staging is not complete until after surgery to remove the tumor. (Surgery for colorectal cancer is described in the “Treatment” section.)
Doctors describe colorectal cancer by the following stages:
- Stage 0: The cancer is found only in the innermost lining of the colon or rectum. Carcinoma in situ is another name for Stage 0 colorectal cancer.
- Stage I: The tumor has grown into the inner wall of the colon or rectum. The tumor has not grown through the wall.
- Stage II: The tumor extends more deeply into or through the wall of the colon or rectum. It may have invaded nearby tissue, but cancer cells have not spread to the lymph nodes.
- Stage III: The cancer has spread to nearby lymph nodes, but not to other parts of the body.
- Stage IV: The cancer has spread to other parts of the body, such as the liver or lungs.
- Recurrence: This is cancer that has been treated and has returned after a period of time when the cancer could not be detected. The disease may return in the colon or rectum, or in another part of the body.
Many people with colorectal cancer want to take an active part in making decisions about their medical care. It is natural to want to learn all you can about your disease and treatment choices. However, shock and stress after the diagnosis can make it hard to think of everything you want to ask your doctor. It often helps to make a list of questions before an appointment.
To help remember what your doctor says, you may take notes or ask whether you may use a tape recorder. You may also want to have a family member or friend with you when you talk to your doctor — to take part in the discussion, to take notes, or just to listen.
You do not need to ask all your questions at once. You will have other chances to ask your doctor or nurse to explain things that are not clear and to ask for more details.
Your doctor may refer you to a specialist who has experience treating colorectal cancer, or you may ask for a referral. Specialists who treat colorectal cancer include gastroenterologists (doctors who specialize in diseases of the digestive system), surgeons, medical oncologists, and radiation oncologists. You may have a team of doctors.
Getting a Second Opinion
Before starting treatment, you might want a second opinion about your diagnosis and treatment plan. Many insurance companies cover a second opinion if you or your doctor requests it.
It may take some time and effort to gather medical records and arrange to see another doctor. Usually it is not a problem to take several weeks to get a second opinion. In most cases, the delay in starting treatment will not make treatment less effective. To make sure, you should discuss this delay with your doctor. Sometimes people with colorectal cancer need treatment right away.
The choice of treatment depends mainly on the location of the tumor in the colon or rectum and the stage of the disease. Treatment for colorectal cancer may involve surgery, chemotherapy, biological therapy, or radiation therapy. Some people have a combination of treatments. These treatments are described below.
Colon cancer sometimes is treated differently from rectal cancer. Treatments for colon and rectal cancer are described separately below.
Your doctor can describe your treatment choices and the expected results. You and your doctor can work together to develop a treatment plan that meets your needs.
Cancer treatment is either local therapy or systemic therapy:
- Local therapy: Surgery and radiation therapy are local therapies. They remove or destroy cancer in or near the colon or rectum. When colorectal cancer has spread to other parts of the body, local therapy may be used to control the disease in those specific areas.
- Systemic therapy: Chemotherapy and biological therapy are systemic therapies. The drugs enter the bloodstream and destroy or control cancer throughout the body.
Because cancer treatments often damage healthy cells and tissues, side effects are common. Side effects depend mainly on the type and extent of the treatment. Side effects may not be the same for each person, and they may change from one treatment session to the next. Before treatment starts, your health care team will explain possible side effects and suggest ways to help you manage them.
You may want to ask your doctor these questions before treatment begins:
- What is the stage of the disease? Has the cancer spread?
- What are my treatment choices? Which do you suggest for me? Will I have more than one kind of treatment?
- What are the expected benefits of each kind of treatment?
- What are the risks and possible side effects of each treatment? How can the side effects be managed?
- What can I do to prepare for treatment?
- How will treatment affect my normal activities? Am I likely to have urinary problems? What about bowel problems, such as diarrhea or rectal bleeding? Will treatment affect my sex life?
- What will the treatment cost? Is this treatment covered by my insurance plan?
Surgery is the most common treatment for colorectal cancer.
- Colonoscopy: A small malignant polyp may be removed from your colon or upper rectum with a colonoscope. Some small tumors in the lower rectum can be removed through your anus without a colonoscope.
- Laparoscopy: Early colon cancer may be removed with the aid of a thin, lighted tube (laparoscope). Three or four tiny cuts are made into your abdomen. The surgeon sees inside your abdomen with the laparoscope. The tumor and part of the healthy colon are removed. Nearby lymph nodes also may be removed. The surgeon checks the rest of your intestine and your liver to see if the cancer has spread.
- Open surgery: The surgeon makes a large cut into your abdomen to remove the tumor and part of the healthy colon or rectum. Some nearby lymph nodes are also removed. The surgeon checks the rest of your intestine and your liver to see if the cancer has spread.
When a section of your colon or rectum is removed, the surgeon can usually reconnect the healthy parts. However, sometimes reconnection is not possible. In this case, the surgeon creates a new path for waste to leave your body. The surgeon makes an opening (stoma) in the wall of the abdomen, connects the upper end of the intestine to the stoma, and closes the other end. The operation to create the stoma is called a colostomy. A flat bag fits over the stoma to collect waste, and a special adhesive holds it in place.
For most people, the stoma is temporary. It is needed only until the colon or rectum heals from surgery. After healing takes place, the surgeon reconnects the parts of the intestine and closes the stoma. Some people, especially those with a tumor in the lower rectum, need a permanent stoma.
People who have a colostomy may have irritation of the skin around the stoma. Your doctor, your nurse, or an enterostomal therapist can teach you how to clean the area and prevent irritation and infection. The “Rehabilitation” section has more information about how people learn to care for a stoma.
The time it takes to heal after surgery is different for each person. You may be uncomfortable for the first few days. Medicine can help control your pain. Before surgery, you should discuss the plan for pain relief with your doctor or nurse. After surgery, your doctor can adjust the plan if you need more pain relief.
It is common to feel tired or weak for a while. Also, surgery sometimes causes constipation or diarrhea. Your health care team monitors you for signs of bleeding, infection, or other problems requiring immediate treatment.
You may want to ask your doctor these questions before having surgery:
- What kind of operation do you recommend for me?
- Do I need any lymph nodes removed? Will other tissues be removed? Why?
- What are the risks of surgery? Will I have any lasting side effects?
- Will I need a colostomy? If so, will the stoma be permanent?
- How will I feel after the operation?
- If I have pain, how will it be controlled?
- How long will I be in the hospital?
- When can I get back to my normal activities
Chemotherapy uses anticancer drugs to kill cancer cells. The drugs enter the bloodstream and can affect cancer cells all over the body.
Anticancer drugs are usually given through a vein, but some may be given by mouth. You may be treated in an outpatient part of the hospital, at the doctor’s office, or at home. Rarely, a hospital stay may be needed.
The side effects of chemotherapy depend mainly on the specific drugs and the dose. The drugs can harm normal cells that divide rapidly:
- Blood cells: These cells fight infection, help blood to clot, and carry oxygen to all parts of your body. When drugs affect your blood cells, you are more likely to get infections, bruise or bleed easily, and feel very weak and tired.
- Cells in hair roots: Chemotherapy can cause hair loss. Your hair will grow back, but it may be somewhat different in color and texture.
- Cells that line the digestive tract: Chemotherapy can cause poor appetite, nausea and vomiting, diarrhea, or mouth and lip sores.
Chemotherapy for colorectal cancer can cause the skin on the palms of the hands and bottoms of the feet to become red and painful. The skin may peel off.
Your health care team can suggest ways to control many of these side effects. Most side effects usually go away after treatment ends.
You may find it helpful to read NCI’s booklet Chemotherapy and You.
Some people with colorectal cancer that has spread receive a monoclonal antibody, a type of biological therapy. The monoclonal antibodies bind to colorectal cancer cells. They interfere with cancer cell growth and the spread of cancer. People receive monoclonal antibodies through a vein at the doctor’s office, hospital, or clinic. Some people receive chemotherapy at the same time.
During treatment, your health care team will watch for signs of problems. Some people get medicine to prevent a possible allergic reaction. The side effects depend mainly on the monoclonal antibody used. Side effects may include rash, fever, abdominal pain, vomiting, diarrhea, blood pressure changes, bleeding, or breathing problems. Side effects usually become milder after the first treatment.
You may find it helpful to read NCI’s booklet Biological Therapy.
You may want to ask your doctor these questions before having chemotherapy or biological therapy:
- What drugs will I have? What will they do?
- When will treatment start? When will it end? How often will I have treatments?
- Where will I go for treatment? Will I be able to drive home afterward?
- What can I do to take care of myself during treatment?
- How will we know the treatment is working?
- Which side effects should I tell you about?
- Will there be long-term effects?
Radiation therapy (also called radiotherapy) uses high-energy rays to kill cancer cells. It affects cancer cells only in the treated area.
Doctors use different types of radiation therapy to treat cancer. Sometimes people receive two types:
- External radiation: The radiation comes from a machine. The most common type of machine used for radiation therapy is called a linear accelerator. Most patients go to the hospital or clinic for their treatment, generally 5 days a week for several weeks.
- Internal radiation (implant radiation or brachytherapy): The radiation comes from radioactive material placed in thin tubes put directly into or near the tumor. The patient stays in the hospital, and the implants generally remain in place for several days. Usually they are removed before the patient goes home.
- Intraoperative radiation therapy (IORT): In some cases, radiation is given during surgery.
Side effects depend mainly on the amount of radiation given and the part of your body that is treated. Radiation therapy to your abdomen and pelvis may cause nausea, vomiting, diarrhea, bloody stools, or urgent bowel movements. It also may cause urinary problems, such as being unable to stop the flow of urine from the bladder. In addition, your skin in the treated area may become red, dry, and tender. The skin near the anus is especially sensitive.
You are likely to become very tired during radiation therapy, especially in the later weeks of treatment. Resting is important, but doctors usually advise patients to try to stay as active as they can.
Although the side effects of radiation therapy can be distressing, your doctor can usually treat or control them. Also, side effects usually go away after treatment ends.
You may find it helpful to read NCI’s booklet Radiation Therapy and You.
You may want to ask your doctor these questions about radiation therapy:
- Why do I need this treatment?
- When will the treatments begin? When will they end?
- How will I feel during treatment?
- How will we know if the radiation treatment is working?
- What can I do to take care of myself during treatment?
- Can I continue my normal activities?
- Are there any lasting effects?
Treatment for Colon Cancer
Most patients with colon cancer are treated with surgery. Some people have both surgery and chemotherapy. Some with advanced disease get biological therapy.
A colostomy is seldom needed for people with colon cancer.
Although radiation therapy is rarely used to treat colon cancer, sometimes it is used to relieve pain and other symptoms.
Treatment for Rectal Cancer
For all stages of rectal cancer, surgery is the most common treatment. Some patients receive surgery, radiation therapy, and chemotherapy. Some with advanced disease get biological therapy.
About 1 out of 8 people with rectal cancer needs a permanent colostomy.
Radiation therapy may be used before and after surgery. Some people have radiation therapy before surgery to shrink the tumor, and some have it after surgery to kill cancer cells that may remain in the area. At some hospitals, patients may have radiation therapy during surgery. People also may have radiation therapy to relieve pain and other problems caused by the cancer.
Nutrition and Physical Activity
It is important to eat well and stay as active as you can.
You need the right amount of calories to maintain a good weight during and after cancer treatment. You also need enough protein, vitamins, and minerals. Eating well may help you feel better and have more energy.
Eating well can be hard. Sometimes, especially during or soon after treatment, you may not feel like eating. You may be uncomfortable or tired. You may find that foods do not taste as good as they used to. You also may have nausea, vomiting, diarrhea, or mouth sores.
Your doctor, dietitian, or other health care provider can suggest ways to deal with these problems. The NCI booklet Eating Hints has many useful ideas and recipes.
Many people find they feel better when they stay active. Walking, yoga, swimming, and other activities can keep you strong and increase your energy. Whatever physical activity you choose, be sure to talk to your doctor before you start. Also, if your activity causes you pain or other problems, be sure to let your doctor or nurse know about it.
Rehabilitation is an important part of cancer care. Your health care team makes every effort to help you return to normal activities as soon as possible.
If you have a stoma, you need to learn to care for it. Doctors, nurses, and enterostomal therapists can help. Often, enterostomal therapists visit you before surgery to discuss what to expect. They teach you how to care for the stoma after surgery. They talk about lifestyle issues, including emotional, physical, and sexual concerns. Often they can provide information about resources and support groups.
Follow-up care after treatment for colorectal cancer is important. Even when the cancer seems to have been completely removed or destroyed, the disease sometimes returns because undetected cancer cells remained somewhere in the body after treatment. Your doctor monitors your recovery and checks for recurrence of the cancer. Checkups help ensure that any changes in health are noted and treated if needed.
Checkups may include a physical exam (including a digital rectal exam), lab tests (including fecal occult blood test and CEA test), colonoscopy, x-rays, CT scans, or other tests.
If you have any health problems between checkups, you should contact your doctor.
You may wish to get the NCI booklet Facing Forward: Life After Cancer Treatment. It answers questions about follow-up care and other concerns. It also describes how to talk with your doctor about making a plan of action for recovery and future health.