Last Modified: April 16, 2005
Dear OncoLink "Ask The Experts,"
What is the most efficient and reliable method of screening, and is it possible for screening to be done too early in life for those with a history of colon cancer in the family?
Timothy C. Hoops, MD, Clinical Assistant Professor of Medicine in the Gastroenterology Division at the University of Pennsylvania and Director of Gastroenterology at Penn Medicine at Radnor, responds:
The answer to your question will vary greatly depending on whom you ask. There are many possible screening methods ranging from testing the stool for occult blood, undergoing a flexible sigmoidoscopy, getting a barium enema or having a colonoscopy. Additional new methods that are still waiting for proof of effectiveness include testing the stool for mutations in genes known to be associated with colon cancer or CT colonography (virtual colonoscopy). Al the methods have their advocates. I am a strong proponent for screening colonoscopies as they provide direct visualization of the entire colon with the ability to biopsy abnormalities and most importantly, to remove polyps resulting in a decreased risk for cancer in the future. No test is perfect, but this one is the most sensitive for the detection of cancer and polyps. It is also well tolerated and has a low rate of complications associated with it.
As to when to start screening for colon cancer in someone with a family history of colon cancer, it is recommended that if the cancer is in a first-degree relative (parent, sibling or possibly child) he or she should have a screening colonoscopy beginning at age 40 or 10 years younger than the age of onset of the earliest colon cancer in the family. If the test is negative, the procedure should be repeated every 5 years if the family member was diagnosed before the age of 65. One exception to this rule is if there is a strong family history that suggests an inherited gene as the cause for the cancer. Those recommendations would be different and more aggressive.