Diseases & Conditions
Colorectal cancer (cancer of the colon [large intestine] or rectum) is the third most common cancer in men and women. When it is discovered in its early stages, colon cancer is treated with surgery and often cured. However, many individuals with colon cancer have no symptoms until the disease reaches an advanced stage, such as metastasizing (spreading) to other organs. Colorectal cancer is the second leading cause of cancer deaths (after lung cancer) in the United States. Testing persons without signs or symptoms of colon cancer is called screening. Screening for colon cancer is recommended for everyone older than 50 years and especially for individuals who have significant risk factors. The December 17, 2008, issue of JAMA includes an article reporting that cigarette smoking is significantly associated with the occurrence of colorectal cancer.
RISK FACTORS FOR COLON CANCER
The following conditions may put you at higher risk for colon cancer
Age (individuals older than 50 years)
Family history (you are more likely to get colorectal cancer if one of your parents, a brother, or a sister has had the disease)
Personal medical history (you are at increased risk for colon cancer if you have had other types of cancer, a history of colon polyps, or inflammatory diseases of the bowel)
Lifestyle (cigarette smoking, heavy alcohol use, inactivity, obesity, and a high-fat/low-fiber diet place you at increased risk for colon cancer)
SCREENING FOR COLON CANCER
Standard tests used for detecting colon cancer include
Fecal occult blood test (FOBT)—testing stool for small amounts of blood
Sigmoidoscopy (placement of a lighted tube into the rectum to examine the lower part of the colon)
Colonoscopy (a lighted tube with an attached camera inserted through the rectum to view the large bowel and to take tissue samples)
Barium enema (a type of x-ray procedure)
Genetic testing can tell you whether you carry genes (the functional units of heredity) that may eventually cause colon cancer. The sooner this information is known, the sooner diagnostic testing and effective treatment can begin. If you have a strong family history of colon cancer, you should discuss with your doctor having a blood test to look for these genes. The most common genetic changes occur in 2 conditions: hereditary nonpolyposis colorectal cancer (HNPCC, now called Lynch syndrome), an inherited disorder with increased risk for several types of cancer; and familial adenomatous polyposis (FAP), an inherited disorder with many small growths inside the colon that may become cancerous.
FOR MORE INFORMATION
American Cancer Society
Centers for Disease Control and Prevention
American College of Gastroenterology
Source: JAMA. 2008;300(23):2816.