Colon cancer doesn’t just happen. It develops over years, often silently, and is shaped by a combination of inherited and environmental forces. Although the average person has a lifetime risk of about 4%, certain risk factors can push that risk dramatically higher, or lower it with the right choices.

Let’s break this down into the factors you can’t change and the ones you can.

The Biggest Risk Factors: What the Science Says

Non-Modifiable Risks (You can’t change these):

• Age: The older you get, the higher your risk. Most cases are diagnosed after age 50, but rates are rising in adults under 40 as well.
• Family History: If a close relative had colon cancer, especially at a young age, your risk increases significantly. Conditions like Lynch syndrome or familial adenomatous polyposis (FAP) raise lifetime risk dramatically.
• Inherited Gene Mutations: Specific genetic changes, such as in the MLH1 or APC genes, can push your risk above 50% over your lifetime.

Modifiable Risks (You can change these):

• Excess Body Weight: High BMI consistently increases colon cancer risk. Fat tissue isn’t just inert; it releases inflammatory signals and hormones that affect colon cell growth.
• Lack of Physical Activity: Sedentary behavior independently raises your risk.
• Diet: High consumption of red and processed meats has been linked to DNA damage and chronic inflammation in the colon.
• Smoking and Heavy Alcohol Use: Both increase risk through oxidative stress and carcinogen exposure.

Who’s Most at Risk Today?

• Younger Adults: Alarmingly, early-onset colon cancer (under age 50) is increasing, and often diagnosed at later stages.
• Women: Some studies show a slightly higher risk for colon (not rectal) cancer among women in certain populations.
• Racial and Ethnic Groups: Black and Indigenous patients often present with more advanced disease and have worse survival, driven partly by barriers in access to care.

What You Can Do Right Now: Prevention and Screening

Up to 70% of colon cancers may be preventable through lifestyle change and early detection (Giovannucci et al. 2002). Here’s what that looks like:

1. Optimize Your Lifestyle

These changes reduce inflammation, improve insulin sensitivity, and lower colon cancer risk.

• Maintain a healthy weight
• Move regularly
• Prioritize fiber-rich foods, limit red/processed meats
• Avoid smoking and limit alcohol

2. Screen Early, Even If You Feel Fine

Colon cancer often develops silently, without pain or visible symptoms. That’s why regular screening matters.

There are two main types of screening tools to know about:

• Colonoscopy: A direct visual exam of the colon that can detect and remove precancerous polyps in one step. Recommended every 5–10 years starting at age 45, or earlier with family history.
• FIT Testing (Fecal Immunochemical Test): A non-invasive, at-home test that detects hidden blood in your stool, which can be an early sign of cancer or large polyps. It’s recommended annually for people at average risk.

The Bottom Line

Colon cancer is one of the most preventable cancers we face today. Even if your genes put you at risk, your daily habits, and your decision to screen early, can dramatically change your trajectory. Whether you choose a colonoscopy or start with a FIT test, the key is to not wait for symptoms. Prevention starts now.