Colon Cancer

colon cancer, cancer of any part of the colon (often called the large intestine). Colon cancer is the second most common cancer diagnosed in the United States. Epidemiological evidence has shown that a diet high in fat and low in fruits, vegetables, and fiber contributes to the development of the disease. Smoking is also a factor in some types of colon cancer. Statistically, a family history of colon cancer or cancer of the female reproductive organs, a history of colon polyps, or a history of ulcerative colitis puts one at a greater risk of developing colon cancer. Colon cancer is most common in people over age 50.

Several genes that signal a hereditary predisposition to colon cancer have been identified. For example, mutations in either of two genes, MSH2 and MLH1, can predispose a person to hereditary nonpolyposis colorectal cancer (HNPCC). People in HNPCC families can undergo blood tests that can tell them whether they have an affected gene. With the information obtained from such screening, an appropriate course of preventive measures and follow-up tests can be initiated (see genetic testing).

Diagnosis

A sudden change in bowel habits or blood in the feces (often detectable only in a laboratory) may be the first symptoms of colon cancer. In the early stages of the disease there may be no obvious symptoms. Diagnosis is made by physical examination of the rectum and a laboratory examination of blood for carcinoembryonic antigen (CEA), a tumor marker produced by colon cancers. These may be followed by an endoscopic examination of the colon with a sigmoidoscope (to examine the rectum and the adjoining sigmoid colon) or colonoscope (to examine the entire colon). A biopsy of any suspicious tissue, such as a polyp or a flat or depressed lesion, is then examined in a laboratory to determine if cancerous changes are present. If cancer is found, the patient is evaluated to determine the extent of the primary tumor and whether the disease has spread throughout the body.

Treatment

Treatment depends upon the stage of the cancer. The initial treatment is usually local excision of the tumor or excision of a larger part of the colon followed by the joining of the two adjacent ends, a procedure referred to as end-to-end anastomosis. In some cases a colostomy (an opening that allows waste to be expelled through an opening in the abdomen rather than through the anus) is created either temporarily, to allow healing, or permanently, if significant portions of the colon have had to be removed. If the disease is advanced, radiation therapy, chemotherapy, or biological therapies (therapies that stimulate the body's own immune defenses against the disease) may be used in addition to surgery.

Bibliography

See publications of the National Cancer Institute, the American Cancer Society, and the United Ostomy Association.

The Columbia Encyclopedia, 6th ed. Copyright© 2014, The Columbia University Press.

Selected full-text books and articles on this topic

Confronting Cancer: How to Care for Today and Tomorrow
Michael M. Sherry.
Insight Books, 1994
Librarian’s tip: Chap. 3 "Colon and Rectal Cancer"
Understanding Colon Cancer
A. Richard Adrouny.
University Press of Mississippi, 2002
The Angry Gut: Coping with Colitis and Crohn's Disease
W. Grant Thompson.
Perseus Books, 1993
Librarian’s tip: Chap. 17 "IBD and Colon Cancer"
Decoding the Cryptic Origins of Colon Cancer. (NIEHS News)
Twombly, Renee.
Environmental Health Perspectives, Vol. 110, No. 7, July 2002
PEER-REVIEWED PERIODICAL
Peer-reviewed publications on Questia are publications containing articles which were subject to evaluation for accuracy and substance by professional peers of the article's author(s).
Primary Care of the Older Adult: A Multidisciplinary Approach
Mary M. Burke; Joy A. Laramie.
Mosby, 2000
Librarian’s tip: "Colorectal Cancer: Risk Factors" begins on p. 258
Assessing Risks to Health: Methodological Approaches
John C. Bailar III; Jack Needleman; Barbara L. Berney; J. Michael McGinnis.
Auburn House, 1993
Librarian’s tip: Discussion of colon cancer begins on p. 211
Review of Harmful Gastrointestinal Effects of Carrageenan in Animal Experiments. (Research Review)
Tobacman, Joanne K.
Environmental Health Perspectives, Vol. 109, No. 10, October 2001
PEER-REVIEWED PERIODICAL
Peer-reviewed publications on Questia are publications containing articles which were subject to evaluation for accuracy and substance by professional peers of the article's author(s).
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