Colon cancer doesn’t just appear out of nowhere. While lifestyle plays a big role, your family tree might be whispering secrets you need to hear. Have you ever wondered if your aunt’s or father’s diagnosis could mean something for you too? Let’s break it all down and look at how much your family history really matters—and what you can do about it.
What Does “Family History” Really Mean in Colon Cancer?
“Family history” isn’t just a vague idea. In medical terms, it refers to having first-degree relatives (like parents, siblings, or children) or second-degree relatives (like grandparents, aunts, uncles, or cousins) who have been diagnosed with colon cancer.
But not all family history is created equal.
- If your parent or sibling was diagnosed before age 50, that’s considered a stronger risk signal.
- If multiple family members on the same side of the family had colon cancer, that’s another red flag.
So it’s not just about who had it, but also how many and how early.
How Much Does Family History Increase Your Risk?
Here’s the truth: family history can significantly raise your odds.
- Having one first-degree relative with colon cancer roughly doubles your risk.
- If that relative was diagnosed before age 50? Your risk could be even higher.
- Having two or more affected relatives may quadruple your chances.
Let’s put it this way: if the average person has a 1 in 24 lifetime chance of getting colon cancer, someone with a strong family history could be looking at 1 in 10—or worse.
But don’t panic. Risk is not destiny. It just means you need to pay closer attention.
Inherited Syndromes: More Than Just Family History
Sometimes, colon cancer isn’t just running in the family—it’s sprinting.
Conditions like Lynch syndrome and Familial Adenomatous Polyposis (FAP) are inherited disorders that dramatically increase colon cancer risk.
- Lynch syndrome: Often causes cancer at a younger age, and can also lead to other cancers (like uterine or ovarian). People with this condition have up to an 80% lifetime risk of colon cancer.
- FAP: This rare syndrome causes hundreds to thousands of polyps to form in the colon—some before age 20. Left untreated, it almost always leads to cancer.
If your family has a pattern of early cancers or multiple types, it’s worth talking to a doctor about genetic testing.
Is It Genetics or Shared Lifestyle?
Here’s a question worth asking: is it really your genes, or is it the lifestyle you all grew up with?
Families share more than DNA. They share:
- Food habits (hello, processed meats)
- Activity levels (or lack of them)
- Smoking or alcohol use
Sometimes what looks like a genetic pattern is actually a shared environment. So even if no genetic mutation is found, a “family pattern” of colon cancer still deserves attention.
When Should You Get Screened If You Have a Family History?
Here’s where things get proactive.
If you have a first-degree relative diagnosed with colon cancer:
- Start screening 10 years before their age of diagnosis, or at age 40, whichever comes first.
- And don’t stop at just one colonoscopy. You may need more frequent follow-ups (every 5 years instead of 10).
And if you have Lynch syndrome or FAP? You may need to start even earlier—some as young as 20 to 25 years old.
Talk to a gastroenterologist. Don’t wait until symptoms appear. Early screening saves lives.
What to Do If a Family Member Gets Diagnosed
So someone in your family just got the call. Now what?
Take action—not panic.
- Talk to them: Ask about the type of cancer, their age at diagnosis, and any genetic testing done.
- Gather your family history: Include all relatives and note who had colon cancer (or any cancer).
- Speak to your doctor: Bring that history to your next appointment.
- Consider a referral to a genetic counsellor. They can assess your personal risk and recommend whether genetic testing is needed.
Knowledge is power. And it might even save your life.
Genetic Testing: Who Needs It and What to Expect
Not everyone with a family history needs genetic testing—but for some, it’s a game changer.
You may want to consider it if:
- You have multiple relatives with colon or other cancers
- A family member had cancer before age 50
- You or someone in your family was diagnosed with Lynch syndrome or FAP
The test is usually a simple blood or saliva sample. But the results? They can be complex.
A genetic counsellor can help you understand:
- What your results mean
- What steps to take next
- Whether your children or siblings should be tested too
How to Talk About Family History with Your Doctor
Bringing up family cancer history can feel awkward. But it matters.
Try these tips:
- Be specific: “My dad had colon cancer at 52,” is more useful than “Cancer runs in the family.”
- Bring a list: Write down names, ages at diagnosis, and cancer types.
- Ask direct questions: “Given my family history, when should I start screening?”
You don’t need to have all the answers—just the right questions.
Prevention Tips for High-Risk Families
Even if colon cancer runs in your family, there’s plenty you can do to lower your odds.
- Eat more fibre, less red meat
- Exercise regularly
- Limit alcohol and quit smoking
- Maintain a healthy weight
Also, consider aspirin therapy—some research shows it may reduce risk in people with Lynch syndrome. But only under a doctor’s guidance.
In short, don’t just inherit risk—inherit resilience.
Myths About Colon Cancer and Family History
Let’s bust some common myths.
- Myth: If no one in my family has colon cancer, I’m safe.
- Fact: Most cases happen in people without a family history.
- Myth: Only old people get colon cancer.
- Fact: Rates are rising among people under 50.
- Myth: If I feel fine, I don’t need a colonoscopy.
- Fact: Colon cancer can grow silently for years.
So don’t let myths lull you into delay. Take action early.
Final Thoughts
Family history isn’t a sentence—it’s a signal. If colon cancer has touched your family, let that be your wake-up call. Talk to your doctor, ask the hard questions, and take control of your health.
Because knowing your risk isn’t scary. Not knowing? That’s the real danger.
References
- “Family History and Colorectal Cancer Risk”, American Cancer Society, 2022. https://www.cancer.org
- “Who Should Get Genetic Counseling and Testing for Inherited Colorectal Cancer?”, CDC, 2023. https://www.cdc.gov
- “Lynch Syndrome: What You Need to Know”, Mayo Clinic, 2022. https://www.mayoclinic.org
- “Colorectal Cancer Screening Recommendations”, U.S. Preventive Services Task Force, 2021. https://www.uspreventiveservicestaskforce.org
- “Aspirin and Colorectal Cancer Prevention in Lynch Syndrome”, The Lancet, 2020. https://www.thelancet.com