Adjuvant Chemotherapy for Stage II Colon Cancer

August 16, 2004

To help doctors give their patients the best possible care, the American Society of Clinical Oncology (ASCO) developed evidence-based recommendations for adjuvant chemotherapy for stage II colon cancer. This guide for patients is based on ASCO's recommendations.

Key Messages:

  • Adjuvant chemotherapy is additional treatment given after surgery to lower the risk of the cancer returning.
  • Chemotherapy after surgery is not recommended for routine use in patients with stage II colon cancer.
  • Talk with your doctor about the risks and benefits of adjuvant chemotherapy.


Colon cancer is a disease in which the normal cells in the lining of the colon begin to change in a way that causes them to grow uncontrollably and form a mass of cells, called a tumor. If a tumor is large enough, it can interfere with the normal function of the colon, such as digesting food and passing waste. The colon is part of the large intestine; the rectum is the last few inches of the colon, and the treatment of tumors in this area may differ from other areas of the colon.

Staging is a way of describing the cancer, such as its size, and whether or where the cancer has spread. Cancer may spread through the blood or lymphatic system. The lymphatic system is part of the immune system and drains fluid from body tissues through a series of tubes. Lymphatic fluid is filtered in small, bean-shaped organs called lymph nodes. When cancer cells travel in the lymphatic system, they become trapped in the lymph nodes. Stage II colon cancer means that the cancer has spread through the wall of the colon and may have spread to nearby tissues or organs, but has not spread to the nearby lymph nodes.

Adjuvant Therapy

Adjuvant therapy is additional treatment given after surgery to reduce the risk that the cancer will come back. Chemotherapy is the use of drugs to treat cancer.

Patients may receive chemotherapy as an injection into a vein or as a pill that can be taken by mouth. Some drugs are given continuously over several days; some are given several times a week. Adjuvant chemotherapy for colon cancer usually includes a drug called fluorouracil (5-FU). Leucovorin (Wellcovorin), irinotecan (Camptosar), and oxaliplatin (Eloxatin) may be given in addition to 5-FU. Most adjuvant chemotherapy treatment schedules last for about six to eight months.

However, chemotherapy can damage healthy cells along with cancer cells. Patients receiving chemotherapy may experience the following side effects, especially if more than one drug is used. These side effects can usually be treated and often go away once treatment is finished. However, in some patients, symptoms of peripheral neuropathy may continue.

  • Tiredness (fatigue)
  • Nausea and vomiting
  • Diarrhea and abdominal cramping
  • Low white blood cell count
  • Mouth sores (mucositis)
  • Myelosuppression, which means the bone marrow stops producing blood cells
  • Nerve damage (peripheral neuropathy), such as tingling, numbness, or pain in the hands and feet

Chemotherapy affects people in different ways. Some patients experience mild side effects, while others require hospitalization because of these side effects. Occasionally, these side effects become life-threatening. The risk of dying from the adjuvant chemotherapy is very low, less than 1%, but may be higher in patients who are older and have other health issues. Talk with your doctor about the risk of side effects from adjuvant chemotherapy, how long they could last, and how to treat them.


Adjuvant chemotherapy is not recommended for routine use in patients with stage II colon cancer. However, in certain situations, it may be reasonable for you and your doctor to consider adjuvant chemotherapy. This recommendation is based on the results of clinical trials, which show that patients who receive adjuvant chemotherapy have about a 4% to 5% greater chance of survival at five years after surgery, compared with patients who did not receive adjuvant chemotherapy. (The exact benefit is not known with certainty because not enough stage II patients have been included in clinical trials.)

In other words, patients who receive chemotherapy after surgery have a very small chance of reducing the risk of their cancer coming back compared with patients who do not receive the extra treatment. Given the potential risks of chemotherapy, patients should talk to their doctors about whether this small benefit is worth the risk of extra treatment.

What This Means for Patients

Adjuvant chemotherapy for stage II colon cancer may lower the risk of the cancer coming back, but is also associated with potentially serious side effects. To learn more about adjuvant chemotherapy for colon cancer, talk with your doctor about the stage of your cancer, your medical history, your overall health, and the risks and benefits of adjuvant treatment, including the potential side effects.

Questions to Ask the Doctor

  • What is the stage of my cancer?
  • If I decide to receive adjuvant chemotherapy, what is my prognosis (chance of recovery)?
  • If I decide not to receive adjuvant chemotherapy, what is my prognosis?
  • What are the drugs, timing, duration, and schedule of the adjuvant treatment I might consider?
  • What are the benefits of adjuvant chemotherapy?
  • What are the side effects and other risks of adjuvant chemotherapy?
  • Are there any medical factors related to my overall health that would make it harder for me to undergo adjuvant therapy?
  • Are there specialized tools that can help estimate survival based on my personal information?
  • Am I eligible for a clinical trial?
  • Where can I find more information?

Helpful Links

Read the entire clinical practice guideline at

Guide to Colorectal Cancer

ASCO Answers Fact Sheet: Colorectal Cancer

Understanding Chemotherapy

About ASCO's Guidelines

To help doctors give their patients the best possible care, ASCO asks its medical experts to develop evidence-based recommendations for specific areas of cancer care, called clinical practice guidelines. Due to the rapid flow of scientific information in oncology, new evidence may have emerged since the time a guideline or assessment was submitted for publication. As a result, guidelines and guideline summaries, like this one, may not reflect the most recent evidence. Because the treatment options for every patient are different, guidelines are voluntary and are not meant to replace your physician's independent judgment. The decisions you and your doctor make will be based on your individual circumstances. These recommendations may not apply in the context of clinical trials.

The information in this guide is not intended as medical or legal advice, or as a substitute for consultation with a physician or other licensed health care provider. Patients with health care-related questions should call or see their physician or other health care provider promptly, and should not disregard professional medical advice, or delay seeking it, because of information encountered in this guide. The mention of any product, service, or treatment in this guide should not be construed as an ASCO endorsement. ASCO is not responsible for any injury or damage to persons or property arising out of or related to any use of this patient guide, or to any errors or omissions.


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