What is the Risk of Colorectal Cancer by Age?

Age is an important risk factor for colorectal cancer, but the face of cancer is changing.^1,6 Roughly 93% of colorectal cancers are still diagnosed in people 45 and older.¹⁶ Yet colorectal cancer is now the leading cause of cancer-related deaths among men under 50—and the second leading cause among women under 50—having climbed from fifth place in this age group since the early 1990s.¹⁹

That shift is why understanding your own risk matters at every age, not just after a milestone birthday. Overall, about 1 in 25 men and 1 in 26 women will develop colorectal cancer in their lifetime.¹⁷

Knowing the risk factors for colorectal cancer is your first step toward prevention. Most Americans are at an average risk of colorectal cancer, but certain lifestyle choices can increase your risk. Risk factors related to lifestyle are considered modifiable risk factors. Modifiable risk factors for colorectal cancer include:^7,16

• Eating a diet high in red and processed meat

• Cooking meat at very high temperatures (i.e. frying)

• Eating too little fiber, fruit, and vegetables

• Not getting enough physical activity

• Having obesity

• Living with type 2 diabetes

• Smoking or using other tobacco products

• Moderate-to-heavy drinking

• Having low vitamin D levels

These are worth taking seriously, because they account for a large share of cases—and unlike age or genetics, they're within your control. Other risk factors are considered non-modifiable. Non-modifiable risk factors for colorectal cancer are:^7,16

• Age

• Sex at birth

• Inherited conditions related to colorectal cancer (familial adenomatous polyposis, Lynch syndrome, Peutz-Jeghers syndrome, MUTYH-associated polyposis, and cystic fibrosis)

• Inflammatory bowel disease (Crohn's disease and ulcerative colitis)

• History of gallbladder removal

• A personal or family history of colorectal cancer or precancerous polyps

• Race and ethnicity—American Indian and Alaska Native populations have the highest incidence rates in the U.S., followed by Black Americans; Ashkenazi Jewish heritage also carries elevated risk

Having certain non-modifiable risk factors for colorectal cancer, including inherited conditions, inflammatory bowel disease, and a family history of colorectal cancer, places you at a higher risk of colorectal cancer than the average person. However, having these risk factors doesn't necessarily mean you'll develop colorectal cancer.

Cancer is a multifactorial disease, and many variables contribute to its development. Aging is one of the most important non-modifiable risk factors for colorectal cancer. For several reasons, age strongly affects colorectal cancer risk. Let's explore how age affects risk.

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Colorectal cancer risk climbs steadily with age, but the trend within each age group is moving in different directions—falling among older adults, rising among younger ones. Here's how that looks across age bands:

A few additional patterns are worth knowing:^1,6

• Diagnoses cluster right at the screening threshold. Cases appear more often in the first couple of years after the recommended start age than in the years just after—not because risk jumps, but because screening finds cancers that were already there.

• Globally, colorectal cancer among young people is increasing in many countries, with the greatest increases in Australia, New Zealand, the United States, and South Korea.

• Across all ages in the United States, colorectal cancer is the third most common cancer—and a leading cause of cancer-related death, ranking third among men and fourth among women (second when both are combined).

• The number of colorectal cancer cases among older adults has stabilized or decreased in many countries.

These statistics highlight the fact that screening is key to prevention. Screening has led to a decrease in colorectal cancer cases among older people.^1,4,6 As a result, the United States Preventive Services Task Force (USPSTF) lowered the initial screening age for colorectal cancer from age 50 to age 45.⁸

A colonoscopy is an example of a screening test that finds and removes precancerous growths before they can become cancer.⁴ That makes colorectal cancer unusual among cancers—most are not caught at a precancerous stage.⁴

Timing is what makes this possible. Most colorectal cancers begin as polyps—small growths on the lining of the colon or rectum—and those polyps typically take years to become cancerous.¹² That slow progression creates a long window in which a screening test can find and remove a growth before it ever turns into cancer, which is why an interval of several years between tests is enough for most people.

Stage at diagnosis is the strongest predictor of survival in colorectal cancer. When the cancer is still confined to the colon or rectum, the five-year relative survival rate is about 91%. Once it has spread to distant organs, that figure drops to roughly 13%.¹⁸ Yet only about a third of colorectal cancers are caught at that earliest, most treatable stage—which is the case for screening on schedule rather than waiting for symptoms.¹⁸

Cancer is a complex disease with many factors at play, but it's ultimately caused by uncontrolled cell growth.⁹ Your genes determine how your cells grow, but your lifestyle and environment can alter the way your genes function. For example, obesity can lead to inflammation, which is known to contribute to cancer development.¹⁰ Moreover, inflammation can disrupt the way your cells communicate, leading to cancer.^9,10

As we age, genetic changes accumulate over time, increasing our risk of cancer. Aging also places you at a greater risk for other diseases associated with colorectal cancer. For example, your risk of type 2 diabetes increases as you age and can consequently increase your risk of colorectal cancer.

Yet, why are younger people developing colorectal cancer more often? While cancer research continues to search for answers, there are likely several contributing factors to the increasing rates of colorectal cancer among young people. These factors include rising rates of obesity, increased consumption of processed foods, changes in the gut microbiome, and environmental chemicals.^2,5 Notably, researchers have not been able to explain the surge through genetics alone—many early-onset cases appear to occur sporadically, without an identifiable inherited syndrome.^5,20

Your age is not the only determinant of your risk of colorectal cancer. It is also important to consider your family history—up to 30% of people diagnosed with colorectal cancer have a family history of the disease.⁴ Individuals with certain genetic diseases are also more likely to develop colorectal cancer, highlighting how our genes can drive cancer onset.^7,11,12

Family history isn't all-or-nothing—it scales:^7,11

• Having a parent, sibling, or child diagnosed with colorectal cancer raises your risk to roughly two to three times that of the general population.

• If that relative was diagnosed at a young age, or more than one close relative has been affected, risk climbs higher still.

• About 5% of colorectal cancers trace to an inherited syndrome such as Lynch syndrome, familial adenomatous polyposis (FAP), or MUTYH-associated polyposis.

If any of this describes your family, you may not be at average risk—which changes when your screening should start. Genetic counseling and testing can also clarify your risk if an inherited syndrome is suspected.¹¹

Recognizing the signs of colorectal cancer can be difficult. Signs of colorectal cancer are often similar to symptoms we all experience from time to time due to indigestion. Consult a healthcare provider if you experience any of the following colorectal cancer symptoms:¹³

• Abdominal pain or cramping

• Blood in your stool

• Rectal bleeding

• Change in bowel habits lasting an extended period of time

• Narrow, thin, or ribbon-like stools

• Feeling like you need to have a bowel movement but can't

• Feeling full early in a meal, or a change in appetite

• Unexplained weight loss

• Fatigue or weakness, which can result from iron deficiency caused by slow blood loss

Two things are worth knowing about these symptoms. First, they don't always appear—some colorectal cancers cause none at all until the disease has progressed, particularly when a growth sits in the right side of the colon where stool is still liquid and can move past it.^13,20

Second, symptoms in younger adults are frequently attributed to something more common first. Rectal bleeding gets chalked up to hemorrhoids, bowel changes to stress or diet—and research on early-onset colorectal cancer points to meaningful delays between when symptoms start and when a diagnosis is made.⁵ If a symptom isn't resolving, or you've been told not to worry and nothing has improved, it's reasonable to ask for further evaluation or a second opinion.²⁰

For most people, screening begins at age 45—but "average risk" is a specific category, and several situations call for starting earlier.^8,20

Screening also remains underused: roughly one in three adults in the eligible age range isn't up to date.⁴ Finding an option you'll actually complete matters more than picking the theoretically best test.

There are many testing options available depending on your preferences.^8,15

• Colonoscopy: in-office procedure once every ten years

• Flexible sigmoidoscopy: in-office procedure once every five to ten years

• Virtual colonoscopy: in-office procedure once every five years

• Fecal immunochemical test (FIT or iFOBT): at-home stool test once a year

• Guaiac fecal occult blood test (gFOBT): at-home stool test once a year

• Multitarget stool DNA testing (sDNA-FIT): at-home stool test every three years

• Shield™ liquid biopsy: in-office blood test (ask your healthcare provider how often to have this test)

Colonoscopy remains the reference standard, since it examines the entire colon and allows polyps to be removed during the same procedure.²⁰ At-home stool tests are a reasonable alternative for people at average risk, with the tradeoff that they're done more often and a positive result leads to a colonoscopy for follow-up.⁸

It's essential to find a screening method that works for you. Your preferences may change as you age, but having options can help you find the best choice. Screening is recommended until age 75, at which point it is best to discuss with your healthcare provider whether you should continue screening.⁸

According to the American Cancer Society (ACS), 55% of all colorectal cancers are attributable to lifestyle factors such as having an unhealthy diet, not exercising, drinking excessively, and smoking.⁴ Adopting healthy habits can help you prevent colorectal cancer. Here are some ways to reduce your risk of colorectal cancer at every age, according to the ACS:¹⁴

• Maintaining a healthy weight: Weight can be a sensitive topic, but maintaining a healthy weight is vital to preventing cancer. According to the American Cancer Society, being overweight or obese causes 10.9% of cancer cases among women and 4.8% of cancer cases among men. For colorectal cancer, obesity remains a significant risk factor. Maintaining a healthy weight requires striking a healthy energy balance with mindful eating and consistent physical activity.

• Staying active: Reducing sedentary behavior and engaging in moderate-intensity exercise for 150-300 minutes a week may help prevent cancer. Including physical activity throughout your day can help you maintain a healthy weight.

• Eating a diet rich in fruits and vegetables: Eating healthy today can feel complex, but studies consistently suggest a plant-based, whole-food diet as the best way to stay healthy. Limiting animal products, refined carbohydrates, and added sugars can also help you maintain a healthy weight.

• Getting enough fiber: Aim for about 25 grams of fiber a day from fresh fruit, vegetables, whole grains, beans, and legumes. The typical American diet supplies only 10 to 15 grams, so this is one of the more concrete changes you can make.²⁰

• Drinking in moderation: Drinking in moderation means one drink a day for women and two drinks a day for men. Alcohol in excess can inhibit DNA repair, placing you at a greater risk of cancer.

• Not smoking: Smoking is a known carcinogen and can greatly increase your risk of many types of cancer. This includes e-cigarettes.²⁰

Risk increases with age, and incidence rates are highest in older adults.¹⁶ That said, incidence among adults under 50 has been climbing for years, which is why symptoms matter at any age.^6,21

Because cases were rising in younger adults. The USPSTF lowered the recommended starting age to 45 after evidence showed the benefits of earlier screening outweighed the harms for people in their late forties.⁸

Yes, though it's uncommon. Routine screening isn't recommended at those ages without symptoms or elevated risk—but a persistent symptom like rectal bleeding or a lasting change in bowel habits should be evaluated regardless of how young you are.^13,20

Often at 40, or 10 years before the age your relative was diagnosed—whichever comes first. Your provider will set the plan based on who was affected and how old they were.^11,20

They serve different roles. Colonoscopy examines the whole colon and can remove polyps during the procedure, while stool-based tests like FIT are noninvasive and done annually. For someone at average risk, the test you'll actually complete on schedule is better than the one you keep putting off—and a positive stool test is followed up with a colonoscopy.⁸

No. Many early colorectal cancers cause no symptoms at all, which is the reason screening exists as a separate practice from investigating symptoms.¹³

Everlywell offers a FIT Colon Cancer Screening Test to make screening easier and more comfortable. Virtual care visits are also available wherever you are. If you have questions about colorectal cancer screening, a healthcare provider can discuss your options and help you make an informed decision.