By Muhammed Gulzar Nathani, M.D., F.A.C.P., F.A.C.G. Page ContentYour family and friends may not enthusiastically put colon or rectal cancer at the top of their lists of things to discuss. But colorectal cancer is the third most common cancer in the United States, most often occurring in people older than 50. And according to the American Cancer Society, if everyone were tested, tens of thousands of lives could be saved each year. March is National Colorectal Cancer Awareness Month, and I can't think of a better time to remind everyone that having a colorectal screening exam could be the difference between life and death.What is colorectal cancer?Colorectal cancer happens when abnormal cells grow in your colon or rectum. These cells can form tumors which may become cancerous. When found early, colorectal cancer is treatable and beatable. Fairly simple screening tests can prevent this cancer, but close to half of the population older than 50 isn't screened.What causes it?Most cases begin as polyps - small, grape-sized growths of excess tissue on the inner surface of the intestine. Not all are cancerous, but they could become so. That's why we doctors prefer to have them removed.What are the symptoms?Colorectal cancer and polyps usually do not cause symptoms in early stages. (That's why early detection is so important.) Once they grow to a significant size, symptoms may start. See your doctor if you have any of these symptoms:Blood in stoolsA change in your bowel habits, such as more frequent stools or a feeling that your bowels are not emptying completelyIron deficiency anemiaUnexplained abdominal pain or weight lossHow is colorectal cancer diagnosed?You will need a test, usually a colonoscopy, that lets the doctor see the inside of your entire colon and rectum. During this test, your doctor will remove polyps or take tissue samples from any areas that don't look normal. The tissue will be microscopically examined for the presence of cancer cells.Colorectal cancer (CRC) screening strategiesCRC screening is now grouped into two categories: prevention tests and cancer detection tests.The American College of Gastroenterology, as well as gastroenterologists at Kelsey-Seybold Clinic, considers the colonoscopy the preferred screening technique. A colonoscopy should be performed beginning at age 50, and every 10 years thereafter. However, not all eligible persons are willing or able to undergo colonoscopy. In these cases, patients may be offered an alternative CRC prevention test, such as a flexible sigmoidoscopy every 5 to 10 years, a computed tomography (CT) colonography every 5 years, or a fecal occult blood test (FOBT).TreatmentSurgery is almost always used to treat colon and rectal cancer. The stage of disease determines if chemotherapy and/or radiation is required. The cancer is removed, and often cured, when found early.PreventionScreening tests can prevent many cases of colon and rectal cancer. They look for a certain disease or condition before any symptoms appear. Regular screening is advised for most people age 50 and older. Although women are at slightly lower risk, current guidelines recommend equal screening strategies for both genders. There is an ongoing debate about starting screening of African-Americans at age 45, but this is not widely practiced yet. If you have a family history of this cancer, you may need to begin screening at age 40, or earlier.Early detectionOur goal at Kelsey-Seybold is prevention and early detection. We combine high-quality compassionate care with technology for diagnosing and treating cancer.So please join us in the fight against colorectal cancer by talking to your primary care physician or gastroenterologist about scheduling a screening exam in the near future.Most widely-used screening tests:Colonoscopy: Examines the entire colon and detects cancerous and pre-cancerous growths in the colon. It is the most effective screening strategy for colorectal cancer. It involves an outpatient procedure performed under sedation in the Endoscopy Suite at Kelsey-Seybold's Surgery Center (located in both Spring and the Main Campus ). People preparing for this procedure need to take a laxative to clean out their bowel before testing to provide a clean view of the colon.Flexible sigmoidoscopy: This procedure uses a flexible scope to examine the lining of the rectum and the lower part of the colon. A sigmoidoscopy is not as thorough as a colonoscopy because only part of the colon is visible. It is done without sedation and often combined with other test such as the fecal occult blood test (FOBT).Fecal occult blood test (FOBT): This test is utilized mostly by primary care physicians. Rather than prevention, it is a cancer detection test that checks for blood hidden in stool. False-positive and false-negative results remain an issue.Barium enema: Rather than using a scope to detect polyps, a contrast enema and X-ray of the colon is used to screen for polyps. This test is usually done in the Radiology Department, It also requires a bowel prep. A barium enema is typically performed when the patient does not want a colonoscopy.Fecal DNA test: A relatively new but expensive cancer detection test. Colorectal cancer sheds DNA in the stool which is then collected and tested. The current use of this test is limited.CT colonography: Also referred to as "virtual colonoscopy." This test is performed in the Radiology Department and read by radiologists. A positive test will usually lead to a colonoscopy. Prior to the test, the patient takes a bowel prep. Low detection rates for flat lesions remain a significant issue.