Colonoscopy exams get a bad rap.
Even though the exam is brief and painless, many people fear and avoid them. Roughly 40 percent of Americans for whom they are recommended are not getting colonoscopies.
Yet colonoscopy is one of the most effective of all cancer prevention methods. The American Cancer Society estimates there will be 142,820 diagnoses of colorectal cancer in 2013 and 50,830 people will die of the disease. As many as 60 percent of colon cancer deaths could be prevented if everyone 50 years old or above underwent colonoscopies, according to the Centers for Disease Control and Prevention (CDC).
“Screening with colonoscopy is a huge opportunity to prevent this disease,” says Charles Fuchs, MD, MPH, director of the Gastrointestinal Oncology Center at Dana-Farber. “Deaths from colorectal cancer have been going down over the past 10 years, and probably 50 percent of that reduction is due to screening.”
Guidelines say that at age 50, everyone should consider having a screening test for colon cancer. (About 90 percent of new cases and 95 percent of colon cancer deaths occur after age 50.) Screening are a test for blood in the stool, repeated annually; an exam with a thin, flexible tube called a sigmoidoscope every five years; or a colonoscopy every 10 years. “If you have a first- degree relative with colon cancer, exams should start between ages 35 and 40,” says Fuchs.
Colonoscopy is the most reliable test, because doctors can visually study the entire colon and rectum, Fuchs says. In addition, a colonoscopy not only can detect cancers in their earliest and most treatable stages; it can also detect pre-cancerous polyps and that can be removed during the exam before they become cancerous.
“People have a misconception of the test – it’s not really that arduous,” says Fuchs. “When you talk to someone who has had precancerous lesions or early cancer because of a colonoscopy, they tell you how glad they are they had the test.”
If the exam is normal, a colonoscopy should be repeated every 10 years up to the age of 75. If the test detects precancerous polyps, the physician will recommend that colonoscopies be repeated more frequently.