Colorectal Cancer
What is it?
Colorectal cancer, one of the most common types of cancer, is the growth of malignant cells in the colon or rectum. Tumors in the colon are slow-growing, but may eventually become large enough to obstruct the digestive tract. The cancer may spread to the liver, lymph nodes, or other parts of the body, and symptoms may not appear until the cancer is quite advanced. However, if detected and treated early, the outlook is optimistic.
What Causes It?
- A diet high in animal fats (especially from red meat) and low in fiber is associated with a higher incidence of colorectal cancer.
- A personal or family history of colon polyps or ulcerative colitis increases the likelihood of colorectal cancer. A family history of colorectal, breast, or endometrial cancer is also a risk factor.
- The risk of colorectal cancer increases after age 40.
Prevention
- Eat a diet low in animal fat and high in fiber.
- Get regular checkups if you have a personal or family history of colon or digestive tract disease.
- The American Cancer Society recommends that people over 40 have an annual digital rectal exam (half of all colorectal cancers occur in the rectum).
- People over 50 also should have an annual stool sample test for hidden bleeding and a colonoscopy (in which a lighted viewing tube is used to examine the colon) every three to five years.
Diagnosis
- Blood and stool samples are taken.
- A digital rectal exam (in which the doctor examines the rectum with a gloved finger) is performed.
- Sigmoidoscopy or colonoscopy is used to view the bowel, during which a biopsy may be taken to determine whether the tumor is benign or malignant.
- A barium enema may be necessary. The barium creates a sharp image of the colon during x-ray.
- Colon cancer should always be suspected (and proper tests conducted) in older men and in post-menopausal women with iron deficiency anemia.
How to Treat It
- Surgery is necessary to remove the tumor. If the cancer is detected early, the surgery may be limited to a bowel resection, in which the cancerous part of the colon is removed and the healthy parts are rejoined. Nearby lymph nodes are also removed.
- If the tumor is blocking the colon, the cancerous part of the colon is removed, and the end of the remaining upper portion of the colon is brought through an opening created in the abdominal wall for waste to pass through, into a bag. This procedure (colostomy) may be temporary, to allow the colon to heal after the operation, or permanent, when cancer is extensive (about 15 percent of cases).
- Radiation therapy may be used before surgery to reduce the size of the tumor or after surgery to destroy remaining cancer cells; chemotherapy may be used to halt the spread of the cancer.
When to Call a Doctor
- Call a doctor if you experience rectal bleeding or if you have changes in your bowel movements that persist for three weeks or more.
- Make an appointment with a doctor if you have a personal or family history of colon disease.
- EMERGENCY Get immediate medical attention if you experience a total inability to pass stools.
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Copyright © 2008 Medletter Associates, LLC
Content excerpted from Johns Hopkins Symptoms and Remedies: The Complete Home Medical Reference.