Colorectal Cancer Treatment: An Introduction

How is colorectal cancer (bowel cancer) treated?

The primary goals of colorectal cancer treatment are to remove tumors, to prevent the cancer from returning, and to prevent the spread of cancer cells to other parts of the body (metastasis). Other goals of cancer care include relieving symptoms and optimizing quality of life.

Colorectal cancer (CRC) treatment options depend on many factors including your cancer's location in the colon or rectum, whether you have early-stage or advanced colorectal cancer, results of biomarker testing, and your overall health. All cancer treatments have potential side effects. Ask your healthcare team about what you can expect from your treatment and how best to manage those side effects.

CRC treatment may be localized to the tumor itself, systemic (given throughout the body), or both, and may include one or more treatment modalities.

What is localized treatment for colorectal cancer?

Treatments are categorized as local when they are aimed at the primary tumor or at a metastatic tumor. Localized treatments are limited to a specific area of the body. Local CRC treatment methods are surgery  and radiation therapy. The goal of surgical resection (removal) is to cut out the cancer, and radiation therapy is used to destroy cancer cells or slow tumor growth.

What is systemic treatment for colorectal cancer?

Treatments that are given throughout the body are called systemic therapies. Systemic treatment for CRC can include conventional chemotherapy drugs, as well as therapies like immunotherapy and targeted therapy. These types of treatments can kill cancer cells directly, help your own immune system to kill cancer cells, or slow cancer growth.

What do I need to know before colorectal cancer treatment?

After a colorectal cancer diagnosis, it is easy to be overwhelmed. You are not alone. Your care team of oncology professionals is here to answer your questions and develop a treatment plan with you. The National Cancer Institute has put together a guide for cancer patients and their families to help with possible questions to ask. To connect with other CRC patients, consider joining an in-person support group or online forum to hear from others or share your own experiences. GCCA has member organizations in more than 40 countries around the world. They offer a variety of support services to CRC patients, including support groups, patient navigation, clinical trial navigation, financial assistance, and helplines.

View our Patient Advocacy Members to find an organization near you.

The most important factor in determining your treatment options is the stage of your cancer. Cancer staging is a process in which biopsy samples, colonoscopy results, and imaging tests like CT scans and PET scans are examined to determine whether your cancer is confined to the colon or rectum, whether your cancer has spread to nearby lymph nodes, or if your cancer has spread to other areas of the body. Stage I and stage II CRC are considered early-stage, while stage III and stage IV (metastatic colorectal cancer, mCRC) are considered advanced cancer.

Your oncology team will use your cancer stage information, as well as factors such as biomarker testing results to determine the best treatment plan for you. Treatment plans for colorectal cancer may include surgery, chemotherapy, immunotherapy, targeted therapy drugs, and radiation therapy.

Typically, stage 0 and stage I colon cancers are treated with surgery alone. Some stage II colon cancer may be treated with just surgery, but if your cancer has features that are associated with a higher risk of recurrence, it will be treated with both surgery and chemotherapy. Stage III colon cancer is treated with surgery and chemotherapy. If your tumor cannot be removed by surgery, you may be treated with chemotherapy and radiation therapy to shrink the tumor before surgery. This is called neoadjuvant therapy or neoadjuvant chemoradiation. Stage IV (metastatic) colon cancer is usually treated with chemotherapy, immunotherapy, and/or targeted therapy. Sometimes, if the cancer has spread to only a few small areas, those metastatic tumors can be removed along with the primary colon cancer.

Stage 0 and stage I rectal cancers are typically treated with surgery alone. Surgery, chemotherapy, and radiotherapy are all used to treat stage II and stage III rectal cancer. The treatment order and the treatment combinations will vary. For example, chemotherapy and radiation treatment may be combined before surgery to shrink the tumor, followed by surgery to remove it, and more chemotherapy after surgery. Stage IV (metastatic) rectal cancer is usually treated with chemotherapy, radiation therapy, immunotherapy, and/or targeted therapy. Sometimes, if the cancer has spread to only a few small areas, those metastatic tumors can be removed along with the primary rectal cancer.

Do I need biomarker testing for colorectal cancer treatment?

It is important to have biomarker testing performed for colorectal cancer.  

Some biomarkers are substances like tumor proteins or circulating tumor DNA (ctDNA) released by your tumor into the blood. Other biomarkers are genetic changes (mutations) in your tumor cells. Genetic mutations that occur in all cells of your body can also be considered biomarkers. Biomarker testing, also called tumor profiling, provides your healthcare team with valuable information about your specific colorectal cancer. Biomarker testing results can lead you to innovative personalized medicine treatments like immunotherapy and targeted treatments that will be most effective for your cancer. Some clinical trials for new treatments are based on biomarkers. Knowing your colorectal cancer biomarkers could connect you to promising new treatments in a clinical trial.

For more information about colorectal cancer biomarkers and how biomarker testing can influence your CRC treatment options, please visit knowyourbiomarker.org.

Are colon cancer treatment and rectal cancer treatment the same?

Treatments for colon cancer and rectal cancer may have some differences. One typical difference is radiation therapy. Radiotherapy is more frequently used in the treatment of rectal cancer, and rarely in the treatment of colon cancer.  

Treatment for both colon cancer and rectal cancer can involve combining therapies.

When the primary treatment (usually surgery) is followed by an additional treatment, the second treatment is called adjuvant therapy. Adjuvant therapy can include chemotherapy, radiation therapy, immunotherapy, and/or targeted therapy.

When a treatment is given before the main treatment, such as radiation therapy to shrink a tumor before surgery, it is called neoadjuvant therapy. Neoadjuvant therapies can also be chemotherapy, radiotherapy, immunotherapy, or targeted therapy.

When should I think about clinical trials for colorectal cancer treatment?

It is helpful to consider clinical trials for CRC treatment at any point in your diagnostic and treatment path. It is a common misconception that clinical trials are a last resort for people who have run out of treatment options. Getting connected to a clinical trial at the time of diagnosis may mean you have more treatment options. Some clinical trial eligibility can even be limited by how many prior treatments you have received.

For more information about clinical trials and resources to help find a CRC clinical trial that could be right for you, please check out our Clinical Trial Awareness program.

What is palliative care for colorectal cancer? Is palliative care the same as hospice care?

Palliative care is care given to prevent and treat pain and other symptoms and to improve quality of life in patients with CRC. Though they do share some principles, palliative care is not the same as hospice care. Palliative therapy, sometimes called supportive care, may be given from the time of diagnosis alongside treatments intended to cure the disease. Palliative care has a patient-centered approach and may include:

What happens after colorectal cancer treatment?

After CRC treatment, you will have regular follow-up care to monitor for cancer recurrence. This is usually done as a combination of imaging tests like CT scans and PET scans, colonoscopy, and blood tests for biomarkers such as carcinoembryonic antigen (CEA) and circulating tumor DNA (ctDNA). In general, recurrence monitoring is done for a period of 5 years. Testing may start out as every few months and become more spread out as time progresses. After the recurrence monitoring period is over, you will continue to have colorectal cancer screening.

Your oncologist may prescribe medications to reduce your risk of CRC recurrence. This is called chemoprevention. Medications may include low-dose aspirin or other nonsteroidal anti-inflammatory drugs (NSAIDs).  

After colorectal cancer treatment, your overall health will also be followed to monitor and manage long-term side effects or complications of cancer treatment. Your team may recommend nutritional changes and physical activity to help in your recovery and reduce the risk of recurrence.  

Talk to your oncology team about your follow-up care plan. The American Cancer Society has published a guide called Preparing for Life After Cancer Treatment that can help and offers guidelines for colorectal cancer survivorship care.