A simple test can gauge your genetic risk for colorectal cancer

Thanks to actress Angelina Jolie’s candor about her own health journey in 2013, most people are familiar with genetic testing for breast cancer. But not as many are familiar with genetic testing for colorectal cancer, and nurse practitioner Nancy O’Connor in the Genetics Department at Cape Cod Healthcare would like to change that.

“We’re trying to get the message out that colorectal cancer really does have a strong hereditary component,” she said. “Colorectal cancer affects men and women equally. Now it is the second leading cause of cancer deaths.”

The most concerning thing is the rise of colon cancer in young people. There has been nearly double the risk of colon cancer in young adults under the age of 55 than was previously true. Sadly, a lot of those patients die young, like actor 43-year-old Chadwick Boseman of Black Panther fame, who passed away in 2020.

“Young people are dying at very high rates because we don’t always start screening early enough,” O’Connor said. The new recommendation is to start colorectal screening at age 45. It used to be at age 50, she said.

“However, for those people who do have a strong family history of colorectal cancer it’s recommended to start ten years younger than that person who had colon cancer. So, let’s say a parent had colon cancer at 40, which would be young, their first-degree relatives could start with colon cancer screening as early as 30.”

Who Qualifies?

Genetic testing is a simple procedure that can be done with a vial of blood or saliva. Those who qualify for genetic testing include:

• Anyone who has a first-degree relative, such as a parent, sibling or child who have had colon cancer before the age of 50.
• Anyone who has a relative with 20 or more lifetime polyps.
• Anyone who has three or more relatives on the same side of the family with similar cancers, including colorectal cancer, ovarian cancer, endometrial cancer or pancreatic cancer.
• Anyone who has a personal history of colorectal cancer at age 65 or younger.

The most common form of hereditary colon cancer is Lynch Syndrome, which is caused by a genetic mutation in five different genes. If a person does test positive for hereditary cancer, they will be advised to follow an enhanced screening and surveilling program, O’Connor said. How often depends on what gene has mutated. If it is a high penetrance gene, which means they are highly likely to develop colorectal cancer, and they have a strong family history, it can mean having a colonoscopy every six months to a year.

“But for most people it would be screening every three to five years as opposed to waiting ten years,” she said.

Lifestyle Adjustments

As part of the genetic counseling process, O’Connor always recommends lifestyle modifications that can reduce the risk of colon cancer for all patients, whether they test positive for a gene mutation or not. These lifestyle modifications include:

• Quit smoking.
• Limit alcohol consumption.
• Eliminate highly processed junk food.
• Reduce excess sugar and carbohydrates.
• Reduce red meat.
• Start a low-dose aspirin therapy to reduce overall inflammation, if a doctor recommends it.
• Exercise regularly.
• Lose weight if overweight because even a modest reduction in weight can help.

“Switching to a more plant-based diet can also help,” O’Connor said. “You don’t have to be 100 percent plant-based but if you start making those changes, they have shown to be very helpful by decreasing the amount of fatty and processed foods and increasing fruits and vegetables.”