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Colorectal Cancer: Chemotherapy

What is chemotherapy?

Finding out you have colorectal cancer can be scary. But with the right treatment, you can survive and thrive. One common option is chemotherapy (chemo).

Chemo uses strong medicines to attack and kill cancer cells. Chemo can quickly target fast-growing cancer cells. But chemo can also attack normal cells. That leads to unwanted side effects.

Is chemotherapy right for me? 

Chemo is an option for many people with cancer. But it’s not right for everyone.

Your situation will determine whether you should have chemo, what type, and the length of treatment. These factors can help decide whether chemo is right for you:

  • What kind of cancer you have (colon or rectal)

  • How much cancer there is and whether it has spread (the stage)

  • The goal of treatment, such as shrinking a tumor before surgery or easing symptoms of advanced cancer

  • How old you are and how healthy you are

  • If you’re worried about side effects

  • What treatments you’ve had before

Your healthcare team may suggest chemo in these cases:

  • Post-surgery. You may get chemo after surgery to kill any remaining cancer cells that have spread or are too small to detect. This is called adjuvant treatment and can reduce the chances of your cancer coming back.

  • As the main treatment. Chemo (along with radiation) may be used as the main treatment for colon or rectal cancer when surgery can't remove it or it has spread to many areas. It's also used for people who aren't healthy enough for surgery.

  • With radiation therapy. Chemo is often given with radiation for colon and rectal cancers. This is called chemoradiation and it helps the radiation work better.

  • Before surgery. Some people need chemo before surgery to shrink the tumor and make it easier to remove. This is called neoadjuvant treatment. It’s often used for rectal cancer in combination with radiation.

  • For returning cancer. Chemo can treat colon or rectal cancer that returns after surgery.

What happens during chemotherapy?

When you're diagnosed with cancer, you'll meet with a provider called a medical oncologist who treats cancer with medicines. You and your provider will talk about your treatment options and what to expect.

You can get chemo as an outpatient or inpatient:

You may get chemo medicine in one of these ways: 

  • Outpatient. This is the most common way to get chemo. You go to a hospital, clinic, or healthcare provider's office and go home the same day.

  • Inpatient. This is rare, but sometimes you must stay at the hospital during treatment.

Your healthcare team will check on you and watch how you're doing during treatment. You won't be alone.

During chemo treatment, you'll have cycles that alternate between treatment days and rest days. The number of treatment days, rest days, and cycles you need will be different from others. Your healthcare provider will tell you your treatment schedule.

You can get chemo in two ways:

  • IV (intravenous). Medicine is put into your blood through a vein. It can drip slowly over many hours or even days. Or it may be given quickly over a few minutes. If your chemo is given over a few days, you'll go home with a small infusion pump. It's in a bag that looks like a waist pack and is disconnected after each session. If the cancer has spread to another organ (like the liver), chemo can also be put directly into the artery leading to the tumor. 

  • Oral.These are pills that you swallow. They're just as strong as IV chemo, but you can take them at home.

Your oncologist will talk with you about these choices and help you decide which one is best for you.

Healthcare provider caring for man having infusion treatment.

Types of chemotherapy medicine

There are different medicines used in chemo. The ones most used for colorectal cancer are:

  • Fluorouracil (5-FU)

  • Capecitabine

  • Irinotecan

  • Oxaliplatin

  • Trifluridine and tipiracil

Usually, two or three of these medicines are combined. They can also be given with targeted therapy. Targeted therapy uses medicines that find and attack cancer cells and don't affect normal cells.

What are possible side effects?

As with most medicines, chemo can cause side effects. The side effects depend on the type and amount of medicine that you’re taking. Not everyone has the same side effects. But your healthcare provider can tell you more about what to expect. Although side effects can be uncomfortable, they usually go away over time after treatment ends. Ask your provider what short or long term side effects you should expect.

You can manage side effects. Talk with your healthcare provider about how to control them and keep them from getting worse.

Some common side effects from chemo for colorectal cancer include:

  • Diarrhea

  • Increased risk for infection

  • Nausea and vomiting

  • Mouth sores

  • Bleeding and bruising more easily

  • Extreme tiredness (fatigue)

  • Loss of weight or appetite

  • Nail or skin changes

Some side effects happen more often with certain medicines:

  • Capecitabine and 5-FU can cause hand-foot syndrome. This makes the palms of the hands and soles of the feet red and painful. They may have peeling, blisters, or sores.

  • Oxaliplatin can cause nerve damage (neuropathy). Symptoms include pain, tingling, and numbness. Neuropathy can last a long time. Oxaliplatin can also cause short-term sensitivity to cold, which makes it painful to swallow or touch something cold. These side effects can be intense, so oxaliplatin is often used for more advanced stages of colon cancer, especially if it's in the lymph nodes.

Talk with your healthcare provider about ways to manage these side effects.

Working with your healthcare team

To help make treatment successful, you should:

  • Write down your medicines. Make a list of all the medicines you take, including chemo. This will help your healthcare team check for possible interactions and side effects.

  • Know what to look for and who to call. Ask your team about what side effects you should expect and when to report them. Know what numbers to call with questions and what times to call. Ask if there's a different number for evenings, holidays, and weekends.

  • Keep a diary of your side effects. Write down your side effects so you can ask questions about managing them. Note the side effect, when you feel it, how often you feel it, and how long it lasts.

Finally, remember that while you’re going through chemo, you are not alone! Your healthcare team is with you at every step.

Online Medical Reviewer: Jessica Gotwals RN BSN MPH
Online Medical Reviewer: Sabrina Felson MD
Online Medical Reviewer: Todd Gersten MD
Date Last Reviewed: 1/1/2023
© 2024 The StayWell Company, LLC. All rights reserved. This information is not intended as a substitute for professional medical care. Always follow your healthcare provider's instructions.