Genes and Screens: How Studying Your Family History Can Prevent Colorectal Cancer

Genes and Screens: How Studying Your Family History Can Prevent Colorectal Cancer

It’s common knowledge that dudes can inherit their old man’s beer gut and bald head. We’re all about improving aesthetics, but today we’ve gotta talk about something more dangerous you could potentially inherit from your family: colorectal cancer.

We have good news and bad news.

The bad news is colorectal cancer is common, affecting about 1 in 23 men. The good news is you can reduce your risk big time with screening and other precautionary measures—that’s where studying up on your family history comes in.

Is Colorectal Cancer Hereditary?

The short answer is, yes, it can be. That said, most cases of colorectal cancer are not hereditary, meaning it wasn’t inherited from a family member.

Here’s a quick breakdown of colorectal cancer cases:

  • 60-70% of cases are sporadic, meaning there’s no familial or hereditary history
  • 20-30% of cases are familial, occurring in more than one member of the same family and may be traced to diet, activity levels, and environment
  • 5-10% of cases are hereditary, meaning a gene mutation is passed down (inherited) through the family, leading to a potentially significant increased cancer risk among all family members

So you know the numbers. Now what?

What (and Who) to Ask About Your Family’s Health History 

Yes, talking about diseases with your family is harder than talking about sports or maybe even politics. But an awkward conversation is worth living cancer-free. 

Start by asking if any of your immediate or extended family has had cancer, what kind it was, and how old they were when they got diagnosed. It can also be helpful to know whether any family members have bowel diseases such as Crohn’s disease or ulcerative colitis.

Getting to know your family history is a great first step, but the only way to know for sure if you’re genetically predisposed to colorectal cancer is through genetic testing. Have a conversation with your doctor about your family history of cancer. They will be able to determine if you meet the criteria for a referral to a genetic counselor who helps you decide if genetic testing is right for you. A genetic test uses your saliva or blood to detect mutations that could increase your risk for cancer. 

If you think you’re at risk but you’re not getting the resources you need, don’t be afraid to advocate for yourself. You can find a local counselor from the National Society of Genetic Counselors or search the National Cancer Institute’s Cancer Genetic Services Directory.

And if you don’t know much about your extended family, check out Fight Colorectal Cancer’s Taboo-ty podcast.

How Your Family History Determines When You should Get Screened

For people at average risk, colorectal cancer screenings should begin at age 45. However, if any of your biological relatives have been diagnosed with cancer before age 60, your risk may be doubled. Accordingly, your screening recommendations will be different.

As a rule of thumb, if you have one immediate relative (parent, sibling, or child) who was diagnosed before age 60 or two immediate relatives diagnosed at any age, you should get screened at age 40 or 10 years younger than the earliest diagnosis in your family—whichever comes first.

For example, if your father was diagnosed with colorectal cancer at age 55, you should get screened at age 40. Or if your brother was diagnosed at age 35, you should get screened at age 25.

Regardless of your genes, all dudes should get a colonoscopy on the books once they hit 45. Doctors say having a colonoscopy can reduce the number of colon cancer-related deaths by 60 percent.

That’s a big-time benefit for having a little camera up your butt.

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