How Genetics Can Raise Your Colorectal Cancer Risk
Colon, rectal and other gastrointestinal cancers often develop without any symptoms, and yet early detection and even prevention are possible with proper screening. We asked colorectal surgeon Joshua Eberhardt, MD, co-director of Loyola’s Gastrointestinal Cancer Risk Assessment Program, to answer common questions about colon and rectal cancer, including genetic risk factors.
What role does genetics play in colorectal cancer risk?
At the most basic level, genetics plays a role in every colorectal cancer. Colorectal cancers usually develop due to genetic changes in normal cells, which subsequently lose their normal growth-regulating mechanisms. The majority of colorectal cancers are probably the result of genetic mutations that occur because of an interplay of several different things, such as diet, lifestyle or smoking. These types of colorectal cancers don’t have an obvious inherited tendency.
Five to 10 percent of colorectal cancers occur because of well-known genetic mutations that are in fact passed down from generation to generation. These are mutations that we know about, we can test for, and, if found, we can provide guidance to patients regarding how they should be treated and looked after as time goes on.
At what age should one be checked?
Generally speaking, people who fit in the category of “average risk” should have a screening colonoscopy at age 50. Average risk means that they have no symptoms, no personal or family history of colorectal cancer or pre-cancerous polyps, and no other colorectal disease like ulcerative colitis or Crohn’s disease. Patients who are at increased risk should have screening done earlier. To determine when exactly one should be screened or see a GI cancer specialist, they should talk with their primary care provider (PCP). Loyola’s primary care physicians are outstanding at providing this kind of guidance to patients.
What type of patient is helped by the genetic risk assessment program?
The patients who are helped the most by our GI Cancer Risk Assessment Program are those who are known or suspected to have colorectal cancer syndrome (the genetic disorders that predispose one to cancer). As a co-director of this program, I am particularly proud of the multidisciplinary team that we have. A patient can come to this clinic and, in one morning, be seen by a genetic counselor, a gastroenterologist and a surgeon. Not everyone needs to see every specialty, so we tailor the visit to the individual’s needs.
How does knowing if someone has or may have a higher genetic risk help?
If a patient is found to be at higher risk it helps in multiple ways. First, knowing gives patients power. We can provide them with information and counseling, and that will allow them to understand their condition and make future decisions. Knowing one's risk factors impacts not only the patient but also their families. Second, this knowledge may lead to recommendations that patients get more frequent testing or even surgery to prevent a problem from arising. Every patient is different.
How much can you reduce the risk — or can you prevent — colorectal cancer?
There is a lot of research going into colorectal cancer prevention. There are some promising studies but nothing definitive yet. When it comes to inherited genetic mutations that predispose to colorectal cancer, how we handle the situation depends on the patient and the exact condition they have. For some conditions, surgery can virtually eliminate or at least drastically reduce the risk of colorectal cancer. For others, frequent colonoscopies and other tests are all that’s needed.
What would you say to someone who says they don’t want to look into their genetic risks because it would just make them worry and wouldn’t help?
I would say that it is totally understandable and lots of people feel this way. It’s a very scary thing, and we get that. However, I would also say that having as much information as possible always helps you make the best decision.
Dr. Eberhardt cares for patients at the Cardinal Bernardin Cancer Center and the Loyola Outpatient Center in Maywood and the Loyola centers for health in Burr Ridge and Homer Glen. His expertise includes colorectal cancer, surgical treatment of inflammatory bowel disease (IBD) and treatment of colon, rectal and anal conditions. The GI Cancer Risk Assessment Program is offered at the Cardinal Bernardin Cancer Center at Loyola University Medical Center.