Chemotherapy for colon cancer uses strong medicines to destroy fast-growing cancer cells in the body. These medicines are usually injected directly into a vein through a needle or taken by mouth as pills.

Chemotherapy for colon cancer often is used in addition to other treatments, such as surgery, radiation therapy, targeted therapy or immunotherapy. Chemotherapy can be used to increase the chance of a cure, decrease the risk of the cancer returning, ease symptoms from the cancer or help people with cancer live longer with a better quality of life.

Chemotherapy for colon cancer also carries a risk of side effects — some temporary and mild, others more serious or permanent. Your healthcare team can help you decide whether chemotherapy for colon cancer is a good choice for you.

Chemotherapy may be considered for certain stages of colon cancer:

• Stage 2 colon cancer. Chemotherapy may be considered for stage 2 colon cancer if the cancer has a high risk of recurrence.
• Stage 3 colon cancer. Chemotherapy is commonly used to treat stage 3 colon cancer. After surgery, it's often used to kill any remaining cancer cells and reduce the risk of recurrence.
• Stage 4 colon cancer. For colon cancer that has spread to other areas in the body, called metastatic cancer, chemotherapy can help control the cancer, improve survival outcomes and better quality of life.

Chemotherapy for colon cancer may be given:

After surgery for colon cancer, called adjuvant therapy

After you have surgery to remove colon cancer, your healthcare professional may recommend chemotherapy to destroy any microscopic cancer cells and reduce the risk of the cancer returning. This is known as adjuvant chemotherapy. Adjuvant chemotherapy typically starts within 8 weeks after colon cancer surgery.

Even if no evidence of cancer remains after surgery, adjuvant chemotherapy may still be recommended if you are at a high risk of the cancer returning or spreading to other parts of your body, a process known as metastasis. This risk increases if:

• Cancer cells are found in the lymph nodes near the site of the colon cancer.
• The colon has a tear, called a perforation, at the cancer site.
• The cancer cells are the type to grow and spread quickly, called poorly differentiated or high-grade cancer cells.
• The cancer is causing a blockage, called obstruction, in the intestine.

Before surgery for colon cancer, called neoadjuvant therapy

Chemotherapy given before surgery is known as neoadjuvant therapy or preoperative chemotherapy. This approach is more commonly used for rectal cancer to shrink tumors and make them easier to remove surgically. For colon cancer, neoadjuvant chemotherapy is less common but may be done in certain situations to:

• Allow the surgeon the best chance of removing the cancer completely.
• Enable the surgeon to remove only the cancer, preserving more of the healthy colon and surrounding tissues.
• Improve surgery outcomes, as smaller tumors can lead to less invasive surgeries and fewer complications.
• Decrease the chance the cancer will return.
• Help see how well your cancer responds to chemotherapy, which can give a clearer idea of your outlook and decide on the most effective chemotherapy medicine for you.

As the main treatment for advanced colon cancer

If colon cancer has spread to other parts of your body and surgery isn't an option, chemotherapy can be used as the main treatment. It may be used in combination with targeted therapy.

The main goal of chemotherapy for advanced colon cancer is generally to improve quality and length of life rather than to cure the disease.

During surgery for colon cancer

In certain situations, chemotherapy may be delivered directly during surgery as part of a specialized approach known as cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (HIPEC).

This is a combination cancer treatment used for cancer in the abdominal cavity, called the peritoneum. In cytoreductive surgery and HIPEC, cancer is first surgically removed from the peritoneum. The cavity is then bathed with hot chemotherapy to kill any microscopic cancer cells that remain.

Chemotherapy medicines travel throughout the body. Side effects depend on the medicines you receive and your reaction to them. Some combination medicine therapies cause more-severe side effects. Most side effects are temporary and go away once treatment is finished. However, some side effects may last for a long time.

Side effects of colon cancer chemotherapy typically happen during treatment and may include:

• Nausea and vomiting. These symptoms are often managed with anti-nausea medicines.
• Diarrhea. This is a common issue with many chemotherapy medicines but especially with irinotecan (Camptosar).
• Increased risk of infections. This is due to a decrease in white blood cells.
• Fatigue. Being tired is a common side effect due to the impact on red blood cells.
• Hair loss. Not all chemotherapy medicines cause this, but hair thinning or total hair loss can happen.
• Mouth sores. The lining of the mouth may become sore or develop ulcers.
• Easy bruising or bleeding. This can be caused by low blood platelets.

Some side effects are caused by specific chemotherapy medicines, such as:

• Nerve damage, also called neuropathy. Tingling or numbness in the hands and feet may happen, particularly with medicines like oxaliplatin.
• Hand-foot syndrome. Redness, pain or peeling of the skin on the palms and soles can develop during treatment, especially with medicines like capecitabine or 5-fluorouracil (5-FU).
• Allergies or sensitivities. Reactions may happen in people taking the medicine oxaliplatin, including symptoms such as skin rash, dizziness, trouble breathing and back pain.

It's important to note that not everyone has these side effects, and their severity can vary. Discussing possible risks with your healthcare team before chemotherapy treatment may help manage these effects.

Psychological side effects

Feelings of fear, sadness and isolation can compound the physical side effects of chemotherapy, both during and after treatment. During chemotherapy, you have regular contact with and support from doctors who specialize in cancer, called oncologists, and nurses. Everyone involved is working toward the same goal — completion of treatment with the best possible outcome. When it's over, you can feel as if you're alone, with no one to help you return to the life you had before treatment or deal with fears of colon cancer coming back.

Consider talking with a mental health professional or other healthcare professional who works with people who have cancer. It also may help to talk with someone who has been in the same situation. Connect with others through a hotline, support group or online community for people who have been treated for cancer.

Assess the potential benefits of chemotherapy

When deciding whether chemotherapy is right for you, your healthcare team considers:

• Cancer size and grade. Larger cancers and higher grade cancers are more likely to recur and are more likely to benefit from chemotherapy.
• Lymph node status. If your colon cancer has spread to your lymph nodes, chemotherapy may be recommended.
• Your general health and other medical conditions. Your overall health may affect your ability to tolerate side effects of chemotherapy. Certain health conditions, such as heart disease or diabetes, may affect which medicines are selected for your chemotherapy.
• Genetic profile. Before your care team decides on chemotherapy, your cancer may be tested for certain genetic characteristics. This may help personalize the choice of chemotherapy medicine. Some genetic profiles may prompt a decision to add targeted therapy along with chemotherapy.
• Your preferences. Talk with your healthcare team about your preferences for your care. These can be taken into consideration, especially when other options for therapy are available.

Take steps to improve your overall health

Make healthy choices before cancer treatment so you'll feel strong as your treatment begins. Continuing healthy choices during treatment may help minimize side effects.

Your healthcare team may recommend that you:

• Get plenty of rest. Try to sleep at least 8 hours a night. And add a nap or two during the day, if needed.
• Stay active and make the time to exercise. Exercise can ease fatigue and help you sleep better at night. Try to do at least 15 minutes of light exercise a day, such as walking, yoga or riding an exercise bike.
• Eat a balanced diet rich in fruits, vegetables and whole grains. A well-balanced diet can help you keep up your weight and repair tissues harmed by chemotherapy treatment. Talk with your care team about putting together a nutrition plan.
• Minimize stress. Find a relaxing activity to help reduce stress. Prayer, meditation, yoga or light exercise are all possible ways to relax.
• Avoid infections, such as the common cold and the flu. Talk with your care team about recommended vaccinations, including annual flu vaccines. Also engage in behavior to reduce the risk of infection while on active chemotherapy, such as washing hands or using hand sanitizer before eating and using gloves while doing yardwork.
• See your dentist. The dentist can look for any signs of infection in your teeth or gums.
• Have a blood test. Your healthcare team may do a blood test to check your levels of infection-fighting white blood cells. If the count is low, you may get medicine to raise your white blood cell count and lower the risk of infection during chemotherapy.

Plan ahead for side effects

Ask your healthcare team what side effects you can expect during and after chemotherapy. If you know what to expect, you can prepare. For example, if your chemotherapy treatment will likely cause severe nausea, you may be prescribed antinausea medicines to take before and after each treatment session. Acupuncture also may help with nausea.

Plan for help at home and at work

Many people are able to continue working and doing their usual activities during chemotherapy. Your healthcare team can give you an idea of how much the chemotherapy is likely to affect your usual activities, but it's difficult to predict just how you'll feel.

Prepare by asking for time off work or help at home for the first few days after treatment. If you'll be in the hospital during chemotherapy treatment, arrange to take time off work and find someone to take care of your usual responsibilities at home.

Tell your healthcare team about any medicines or supplements you're taking

Medicines or supplements you're taking, including any herbal supplements, vitamins or medicines you buy without a prescription, may affect the way the chemotherapy medicines work. Your care team may suggest alternative medicines or that you not take the medicines or supplements for a period before or after a chemotherapy session.

The day of treatment

Your healthcare team lets you know what you can and can't eat or drink on the day of your chemotherapy session. It may help to take a family member or friend with you to the treatment session for support and companionship.

Chemotherapy cycles

Chemotherapy for colon cancer is given in cycles. A cycle includes a phase of chemotherapy treatment followed by a rest period. Typically, each cycle lasts 2 to 3 weeks. The schedule can differ based on the specific medicines used.

Both adjuvant and neoadjuvant chemotherapy are often given for about 3 to 6 months, depending on the medicines used and whether or not your cancer is considered high risk. Higher risk cancers may benefit from a longer chemotherapy treatment plan.

The duration of chemotherapy for advanced cancer varies depending on the side effects and how your body is responding to the medicine.

Common chemotherapy medicines for colon cancer

There are a few chemotherapy medicines available to treat colon cancer. Because each person is different, your healthcare team will tailor the type and dose of your medicines. This is called a regimen. A regimen often includes a combination of two or three chemotherapy medicines depending on your type of colon cancer and medical history. Sometimes, targeted therapy medicines are given along with chemotherapy medicines.

Chemotherapy medicines commonly used to treat colon cancer include:

• 5-Fluorouracil (5-FU). This is a widely used chemotherapy medicine that's often combined with leucovorin to enhance effectiveness.
• Capecitabine (Xeloda). Capecitabine is known as a prodrug. A prodrug is a type of medicine that isn't active until it gets inside the body. Once there, it changes into an active form through natural processes, such as enzyme or chemical reactions.
• Irinotecan (Camptosar). This medicine is often used for advanced colon cancer.
• Oxaliplatin. Oxaliplatin is a platinum-based medicine commonly used in combination with other medicines.
• Trifluridine-tipiracil (Lonsurf). This is a combination chemotherapy medicine used to treat cancer that has spread beyond the colon, called metastatic cancer.

Common chemotherapy medicine combinations for colon cancer include:

• FOLFOX. 5-FU, leucovorin and oxaliplatin.
• FOLFIRI. 5-FU, leucovorin and irinotecan.
• XELOX, also called CAPOX. Capecitabine and oxaliplatin.

Where chemotherapy is given

Colon cancer chemotherapy sessions can take place at your doctor's office, at an outpatient unit in a hospital or clinic, or sometimes, at home.

How chemotherapy is given

Chemotherapy medicines for colon cancer can be given in a variety of ways, including:

• Pills. A few colon cancer chemotherapy medicines are taken by mouth in pill form.
• Catheters. An IV needle and tube, called a catheter, is placed in your hand or wrist.
• Ports. A port is a small disc that is placed under your skin. A catheter connects the port to a vein. This port stays in place for the duration of your chemotherapy treatment and eliminates the need to find a suitable vein at each treatment session.
• Pumps. A pump is often small and portable, enabling you to wear it while continuing your daily activities during treatment. Pumps may be used when a continuous infusion of chemotherapy medicines is needed, such as with FOLFOX and FOLFIRI regimens for colon cancer.

Based on the location and stage of your colon cancer, chemotherapy drugs can either be distributed throughout your entire body or targeted to a specific area:

• Systemic chemotherapy. This method uses an IV or pills to put chemotherapy into your bloodstream to treat colon cancer. This way, the medicine reaches all areas of your body.

• Regional chemotherapy. This method focuses on a specific area of the body. Chemotherapy is delivered directly to the cancer site. This helps concentrate the treatment on cancer cells in that area and reduces side effects elsewhere.

  Hepatic artery infusion is a type of regional chemotherapy often used for treating colon cancer that has spread to the liver. This type of treatment delivers chemotherapy directly into the liver's main artery.

A typical chemotherapy session

Not all chemotherapy sessions for colon cancer are alike, but a session might follow this order:

• You have a blood sample drawn for a blood count and other blood tests.
• You meet with your doctor to review your blood test results and assess your overall health.
• Your doctor orders chemotherapy medicine.
• You meet with the member of your healthcare team who's administering your chemotherapy.
• You undergo a brief physical exam to check your temperature, pulse and blood pressure.
• You have the IV catheter inserted.
• You receive medicines to prevent side effects such as nausea, anxiety or inflammation.
• You receive chemotherapy medicine. This may take up to several hours.

After a chemotherapy session

Following a chemotherapy session for colon cancer, you may:

• Have your temporary IV catheter removed.
• Have your vital signs checked.
• Review side effects with your healthcare team.
• Receive prescriptions for medicines you can take at home to help with side effects.
• Be advised on what to eat and drink.
• Receive instructions on proper handling of bodily fluids, such as urine, stool, vomit, semen and vaginal secretions, as these may contain some of the chemotherapy medicine for the next 48 hours. This may simply involve flushing the toilet twice after use.

Some people feel fine after a chemotherapy session and can return to their usual schedules and activities. Others may feel side effects more quickly. You may want to arrange for someone to drive you home afterward, at least for the first few sessions, until you see how you feel.

During the course of chemotherapy

After a few sessions, you may be able to predict more accurately when you'll feel fine and when you may need to cut back on activities. Marking your calendar or keeping a journal may help you track your general response to chemotherapy sessions and plan events accordingly.

Following your colon cancer treatment plan closely is the best way to get the most benefit from chemotherapy. If side effects become too bothersome, discuss them with your healthcare team. It may be possible to adjust the dose or type of chemotherapy medicine you're receiving or prescribe other medicines to help relieve some symptoms such as nausea. If the number of white cells in your blood drops, your doctor may stop your chemotherapy until your white cells return to a safe level.

Relaxation techniques such as meditation and deep breathing may help reduce stress. And exercise has been shown to help improve sleep and lessen fatigue caused by chemotherapy. Wearing wigs, hats or turbans can make hair loss less obvious.

After you complete chemotherapy treatment for your colon cancer, your healthcare team schedules follow-up visits to monitor for long-term side effects and check for colon cancer recurrence. Expect appointments every few months and then less frequently the longer you remain cancer-free.