Colon cancer begins in the colon, also known as large intestine. The colon absorbs water and nutrients from foods. Then it passes solid waste to the rectum.
Cancer is when cells in the body split without control or order. These cells go on to form a growth or tumor. These growths attack nearby tissues. They can also spread to other parts of the body. It’s not clear exactly what causes cancer to develop. It’s likely a mix of genes and the environment.
The risk of colon cancer is higher in those with:
Early colon cancer may not cause symptoms. As it grows, colon cancer may cause:
Colon cancer screening is recommended for adults 50 years or older. Some with risk factors such as family history or related health issues may start earlier. People who are Black, Asian, or Alaskan Native also have a higher risk of colon cancer. Screening tests that can catch early colon cancer or symptoms include:
More tests or exams will be needed if a screening test suggests cancer. The doctor may also ask for tests if a patient complains about specific symptoms. Tests may include:
The exam and test results will confirm cancer and show the stage of cancer. Staging guides treatment. Colon cancer is staged from 0 to 4. Stage 0 is cancer that is still in one area. Stage 4 is a spread to other parts of the body.
Treatment will depend on the stage of cancer and where it is found. It often includes a combination of treatments. Steps may include:
Surgery to remove as much of the cancer as possible. This is the main way to treat colon cancer. Types of surgery include:
Radiation therapy is the use of radiation to kill cancer cells and shrink tumors. It may be given at the same time as chemotherapy. The types are:
It may be used as part of treatment to get rid of cancer or shrink tumors that are causing problems.
Chemotherapy is the use of drugs to kill cancer cells. It may given by mouth, shots, or IV. The drugs enter the bloodstream and travel throughout the body. It may be used to treat cancer that has spread.
These medicines block tumors from growing and spreading. It may be used with other methods. In many cases, these medicines aren’t used until cancer is in later stages.
Some changes in daily habits may decrease the risk of colon cancer:
Screening tests can also help to find polyps. Some polyps have an increased risk of becoming cancer if they are not removed. Screening can help to find and remove them before they become a problem.
American Cancer Society
United Ostomy Associations of America
Canadian Cancer Society
Ostomy Canada Society
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Colorectal cancer screening. EBSCO DynaMed website. Available at: https://www.dynamed.com/topics/dmp~AN~T114074/Colorectal-cancer-screening. Accessed January 29, 2021.
Colorectal cancer screening tests. American Cancer Society website. Available at: https://www.cancer.org/cancer/colon-rectal-cancer/detection-diagnosis-staging/screening-tests-used.html. Accessed January 29, 2021.
General information about colon cancer. National Cancer Institute website. Available at: https://www.cancer.gov/types/colorectal/patient/colon-treatment-pdq. Accessed January 29, 2021.
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Moreno C, Kim DH, Bartel TB, et al. Colorectal cancer screening. American College of Radiology (ACR) Appropriateness Criteria. Available at: https://acsearch.acr.org/docs/69469/Narrative. Updated 2018.
Rex DK, Johnson DA, Anderson JC, et al. American College of Gastroenterology guidelines for colorectal cancer screening 2009. Am J Gastroenterol. 2009;104(3):739-750.
Last reviewed January 2021 by EBSCO Medical Review Board Mohei Abouzied, MD, FACP Last Updated: 1/29/2021