By Dr. C. Allen Justice
Colorectal cancer is the third most common cancer diagnosed in the United States and is the third leading cause of cancer-related deaths.
Despite efforts to increase awareness of the disease, more than 140,000 people continue to be diagnosed with colon cancer annually and more than 51,000 people are expected to die from it in 2012. It affects men and women equally. The disease, however, is largely preventable with regular screening and is treatable, often curable, with early detection.
Colorectal cancer develops slowly over a period of time. Before cancer development, an abnormal growth of tissue called a polyp forms and over time can become a cancer. The period a polyp takes to change into cancer is variable but generally is measured in years. One type of polyp, called an adenoma, has the greatest risk of developing into a cancer. Regular screening and diagnosis at this early, curable stage can help prevent cancer through removal of the precancerous polyps.
Precancerous polyps generally do not cause symptoms. As polyps progress and develop into cancers, warning signs may develop. These may include:
• Rectal bleeding and blood in your stool (bright red, black or very dark).
• A change in your normal bowel movement, especially in the shape or caliber of the stool (e.g., narrow like a pencil).
• Cramping in your lower abdomen or frequent gas pains.
• Discomfort in or the frequent urge to move your bowels when there is no stool present.
• Weight loss without dieting, unexplained anemia and constant fatigue.
The options to screen for colorectal cancer are divided into cancer detection and cancer prevention techniques. The best way to screen for and prevent colorectal cancer is with a colonoscopy, an endoscopic test performed under sedation that evaluates the entire colon through the use of a flexible video scope. A colonoscopy allows for the detection and subsequent removal of any precancerous polyps found, during the same procedure. If the test is normal and you have no increased risk, the next screening exam is generally recommended in 10 years.
Another cancer prevention technique is a flexible sigmoidoscopy, a shorter endoscopic video scope that evaluates only the last half of the colon, in combination with an X-ray called a barium enema to evaluate the first half. Minimal discomfort is noted as these tests are performed without sedation. If abnormalities are noted on the barium enema, then a colonoscopy is recommended to further evaluate. If these tests are normal, the next screening exam is recommended in five years.
Cancer detection techniques include fecal occult blood testing and CT scan colonography. Fecal occult blood testing can only detect cancer once it has developed and does not detect the precancerous polyps. Fecal occult blood testing must be done annually and, if positive, a colonoscopy is recommended. CT colonography, also called virtual colonoscopy, is a relatively new technique that is not widely available and is not generally covered by most insurance carriers.
When to begin colon cancer screening:
• Average risk – no risk factors and no warning signs: All men and women should begin screening at age 50. Because of recent evidence that shows African-Americans develop colorectal cancer at an earlier age, screening is recommended to begin at age 45.
• High risk: All men and women with high risks should begin screening at age 40, or on occasion even sooner. High risk factors include a family history of colorectal cancer or precancerous polyps, especially before age 60, and a personal history of precancerous polyps or inflammatory bowel disease. A family history of multiple cancers involving the breast, ovary, uterus and other organs may also increase your risk.
• Family history of a genetic colon cancer syndrome: These individuals are at extremely high risk of developing colon cancer and should begin screening at a very young age, often in the teens or 20s.
Lifestyle modifications can decrease your risk of colon cancer. Decrease red meat and increase fiber, whole fruits and vegetables in your diet. Calcium supplementation, in the presence of adequate vitamin D, and adequate folate have been shown to help protect against colorectal cancer. Smoking and alcohol increases risk of colorectal cancer. Increase your physical activity and avoid a sedentary lifestyle; obesity increases the risks.
Colorectal cancer is a common but curable and preventable disease, but only if recommended screening procedures are completed. Talk to your primary care physician about getting your colon cancer screening.
Dr. C. Allen Justice is a gastroenterologist with Digestive Health Specialists, P.A. in Tupelo.