Colorectal cancers are the fourth most common cancer in the United States, and the National Cancer Institute estimates about 1 in 20 will develop the cancer in their lifetime. However, thanks to better screening and improved treatments, the death rate associated with colorectal cancers is declining.
Some people are more likely to develop polyps and colorectal cancer than others, especially those with the following risk factors:
- Age over 50
- History of colorectal polyps
- Family history of colon cancer, especially among close relatives such as parents, siblings or children
- Genetic mutations – People with certain genetic conditions face increased risk for colorectal cancer, such as people with:
- Hereditary nonpolyposis colorectal cancer (HNPCC), also known as Lynch Syndrome, is the most common inherited form of colorectal cancer and occurs when a person has an altered HNPCC gene. Accounting for about 2 percent of all colorectal cancers, this type affects people at a younger and the average age at diagnosis is 44.
- Familial adenomatous polyposis (FAP) occurs when a person has an altered APC gene, which causes hundreds of polyps to form in the colon and rectum. Untreated, the condition is likely to cause colon cancer by age 40.
- MYH-associated polyposis also causes the formation of many polyps.
- Personal history of colorectal cancer, or cancer of the ovaries, uterus or breast
- Inflammatory colon conditions, such as ulcerative colitis or Crohn’s disease
- Diet that’s high in animal fat and low in calcium, folate and fiber; obesity, excessive drinking and lack of exercise may also contribute to colorectal cancer risk
Prevention: Take Charge of Your Life
Adopting a healthy lifestyle is one of the best ways to reduce your risk of colorectal and other cancers:
- Avoid all tobacco products. If you smoke, quit now. Smoking has been linked to as many as one in five cases of colorectal cancer. Find the support and guidance you need by calling the New York State Smokers’ Quitline at Roswell Park, at 1-866-NY-QUITS (1-866-697-8487), or visit www.nysmokefree.com for more information.
- Limit alcohol intake
- Eat a high-fiber diet and reduce consumption of fats and red meat
- Maintain a healthy weight
- Exercise regularly
Early Detection: Get Screened
Colon cancer is largely preventable. But you must have a screening test that will detect warning signs such as polyps, abnormal growths, precancerous lesions or early malignancies, long before you notice any symptoms.
Roswell Park recommends all adults be screened for colon and rectal cancer beginning at age 50, unless other risk factors or symptoms indicate screening should begin at an earlier age.
Several screening tests detect (and some also treat) colon polyps. Some tests examine more of the colon than others. A colonoscopy is considered the gold standard because the procedure detects — and removes — polyps. Choices include:
- Colonoscopy: A gastroenterologist or surgeon uses a colonoscope (a thin flexible tube with a light and camera on the end) to examine the lining of your colon and rectum. During this procedure, the entire colon is examined and if polyps are identified, they are removed for testing. Unless you’re at higher than average risk, you’ll need this test once every 10 years.
- Fecal occult blood test (FOBT): Examines a stool sample for hidden or microscopic blood, which could come from a polyp, hemorrhoid, infection, benign inflammatory condition or cancerous lesion. One test type guaiac, checks for heme, the part of your blood that contains iron. Another type, called immunochemical, uses antibodies to find hemoglobin (a blood protein). If blood is detected, you’ll need other tests, such as a colonoscopy, to determine its source. Studies show that FOBT performed every 1-2 years in people ages 50-80 can help reduce the number of deaths due to colorectal cancer by 15-33 percent.
- Double contrast barium enema (DCBE): Also called a lower GI series, in which an enema that contains a barium solution is given. Air is introduced into the colon and a series of x-rays taken. Studies show DCBE detects about 30 - 50 percent of the cancers that can be found with a colonoscopy.
- Sigmoidoscopy: A thin, lighted tube, called a sigmoidoscope is used to examine the lower portion of the colon and the rectum for polyps or suspicious lesions. Any abnormalities can be biopsied at this time. This procedure also requires colon-cleansing preparation.
- Digital rectal exam (DRE): This may be done during a routine physical or gynecological exam. Your healthcare provider inserts a lubricated, gloved finger into the rectum to check for any abnormalities in the lower part of the rectum.
- Virtual colonoscopy: This procedure uses special x-ray equipment, rather than an inserted colonoscope, to view the interior of the colon. The x-ray pictures go to a computer that creates detailed images, highlighting any abnormalities, such as polyps. Whether virtual colonoscopy can reduce the number of deaths from colorectal cancer is not yet known.