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. 

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. 

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 who receive treatment for rectal cancer do not need a permanent colostomy. 

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 spare the liver and lung tissue that might be removed in a regular surgery, 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.

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.

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 the cancer returning.

Currently, eight 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), panitumumab (Vectibix), and aflibercept (Zaltrap). (These last four are described under “Targeted therapy” below.) Some common treatments are:

5-FU

5-FU with leucovorin (Wellcovorin), a vitamin that improves the effectiveness of 5-FU

Capecitabine, an oral form of 5-FU

5-FU with leucovorin and oxaliplatin (called FOLFOX)

5-FU with leucovorin and irinotecan (called FOLFIRI)

Irinotecan alone

Capecitabine with either irinotecan or oxaliplatin

Any of the above with either cetuximab or bevacizumab

FOLFIRI with aflibercept

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.The side effects from chemotherapy usually go away once treatment is finished.

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. 

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.

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. 

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 delivered by 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 advanced colorectal cancer. Recent studies have shown it is also effective as second-line therapy along with chemotherapy. Aflibercept is another type of angiogenesis therapy that is used along with FOLFIRI chemotherapy as a second-line treatment for metastatic colorectal cancer. In addition, the drug regorafenib (Stivarga) was approved in 2012 for patients with metastatic colorectal cancer who have already received certain types of chemotherapy and other targeted therapies.

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. 

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.

Talk with your doctor about possible side effects for a specific medication and how they can be managed. The side effects of targeted treatments include a rash to the face and upper body, which can be prevented or reduced with various treatments. 

Palliative/supportive care

Cancer and its treatment often cause side effects. In addition to treatment to slow, stop, or eliminate the cancer, an important part of cancer care is relieving a person’s symptoms and side effects. This approach is called palliative or supportive care, and it includes supporting the patient with his or her physical, emotional, and social needs.

Palliative care can help a person at any stage of illness. People often receive treatment for the cancer and treatment to ease side effects at the same time. In fact, patients who receive both often have less severe symptoms, better quality of life, and report they are more satisfied with treatment.

Before treatment begins, talk with your health care team about the possible side effects of your specific treatment plan and supportive care options. And during and after treatment, be sure to tell your doctor or another health care team member if you are experiencing a problem, so it is addressed as quickly as possible.

Treatment options by stage

In general, stages 0, I, II, and III are curable with surgery. However, many patients with stage III colorectal cancer receive chemotherapy after surgery to increase the chance of eliminating the disease. Stage IV is not often curable, but it is treatable and the growth of the cancer and the symptoms of the disease can be managed. Clinical trials are also a treatment option for each 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.  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

A remission is when cancer cannot be detected in the body and there are no symptoms. This may also be called ”no evidence of disease” or NED.

A remission can be temporary or permanent. This uncertainty leads to many survivors feeling worried or anxious that the cancer will come back. While many remissions are permanent, it’s important to talk with your doctor about the possibility of the cancer returning. Understanding the risk of recurrence and the treatment options may help you feel more prepared if the cancer does return. 

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. 

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.

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. Supportive care will also be important to help relieve symptoms and side effects.

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

For many patients, a diagnosis of metastatic cancer can be very stressful and, at times, difficult to bear. Patients and their families are encouraged to talk about the way they are feeling with doctors, nurses, social workers, or other members of the health care team. It may also be helpful to talk with other patients, including through a support group.

If treatment fails

Recovery from cancer is not always possible. If treatment is not successful, the disease may be called advanced or terminal cancer.

This diagnosis is stressful, and this is difficult to discuss for many people. 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. Making sure a person is physically comfortable and free from pain is extremely important.

Palliative care given toward the end of a person’s life is called hospice care. You and your family are encouraged to think about where you would be most comfortable: at home, in the hospital, or in a hospice environment. Nursing care and special equipment can make staying at home a workable alternative for many families.

Coping with Side Effects

Fear of treatment side effects is common after a diagnosis of cancer, but it may help to know that preventing and controlling side effects is a major focus of your health care team. This is called palliative or supportive care, and it is an important part of the overall treatment plan, regardless of the stage of disease.

Common side effects from each treatment option for colorectal cancer are described in detail within the Treatment section. Side effects depend on a variety of factors, including the cancer’s stage, the length and dosage of treatment(s), and your overall health.

Before treatment begins, talk with your doctor about possible side effects of each type of treatment you will be receiving. Ask which side effects are most likely to happen, when they are likely to occur, and what can be done to prevent or relieve them. And, ask 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. 

In addition to physical side effects, there may be psychosocial (emotional and social) effects as well. Patients and their families are encouraged to share their feelings with a member of their health care team who can help with coping strategies. 

During and after treatment, be sure to tell the health care team about the side effects you experience, even if you feel they are not serious. Sometimes, side effects can last beyond the treatment period, called a long-term side effect. A side effect that occurs months or years after treatment is called a late effect. Treatment of both types of effects is an important part of survivorship care.

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. I

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. 

Latest 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.