Are You Employing Genetic Testing Correctly for Colorectal Cancer?

This transcript has been edited for clarity.

Hello. I'm Dr David Johnson, professor of medicine and chief of gastroenterology at Eastern Virginia Medical School. Welcome back to another GI Common Concerns.

Today, I wanted to provide some perspective around genetic testing in colorectal cancer: what's required, what's standard, and what you need to know now.

Only in the past couple of decades have we had the ability to perform genetic testing for colorectal cancer. This started in 1991 with the discovery of the abnormality that identified the APC gene that predisposes to familial adenomatous polyposis. Just 2 years later, there was the recognition of the mismatch repair gene abnormalities — MLH1, MSH2, and PMS2 — which were the identifiers for what was then called hereditary polyposis colon cancer and is now known as Lynch syndrome. Since that time, the field has truly evolved and produced a number of other genetic tests.

That brings us to the present day and the question of what you need to be doing now and why you need to be doing it.

The Numbers of Likely Patients With Lynch Syndrome in Your Practice

It's estimated that approximately 1 million people in the United States have Lynch syndrome, but the vast majority of are unaware of this.