What is the Risk of Colorectal Cancer by Age?

Writer: Theresa Vuskovich, DMD

Age is an important risk factor for colorectal cancer, but the face of cancer is changing. ^{[1, 6]} While cancer has been historically associated with advanced age, colorectal cancer is now the leading cause of cancer-related deaths among men under 50, indicating the evolving risk factors associated with CRC. ^{[1, 6]}

Risk Factors of Colorectal Cancer

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]:

• Eating a diet high in red and processed meat
• Cooking meat at very high temperatures (i.e. frying)
• Having obesity
• Living with type 2 diabetes
• Smoking
• Moderate-to-heavy drinking
• Having low vitamin D levels

While these risk factors can increase your risk of colorectal cancer, you can alter these risk factors by adopting healthier habits. Other risk factors for colorectal cancer are considered non-modifiable. Non-modifiable risk factors for colorectal cancer are ^[7]:

• 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
• Family history of colorectal cancer or precancerous polyps
• Ethnicity (American Indians, Alaskan Natives, and Ashkenazi Jews)

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.

Understanding Your Risk of Colorectal Cancer by Age

Here are some key facts and statistics for a better understanding of how colorectal cancer affects people of different ages ^{[1, 6]}:

• In the United States, colorectal cancer cases increased by 17% in people aged 45-49 years between 2018 and 2021.
• In the United States, one out of five colorectal cancer cases in 2019 occurred in people 54 or younger, up from one out of 10 in 1995.
• Due to screening, colorectal cancer cases are more common in individuals aged 50 and 51 than in those aged 52 and 53.
• Globally, the prevalence of colorectal cancer among young people is increasing in many countries, with the greatest increases in Australia, New Zealand, the United States, and South Korea.
• Colorectal cancer is the third most common cancer and the third leading cause of cancer-related death in men and women in the United States.
• The number of colorectal cancer cases among older adults has stabilized or decreased in many countries.

As you can see, there is an alarming increase in colorectal cancer rates among young people in particular. These statistics also 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 detects and removes colorectal cancer during its precancerous stage. ^[4] This makes colorectal cancer unique from many other types of cancer since most cancers are not detected in their precancerous stage. ^[4] Now that you know some facts about colorectal cancer, you may wonder how cancer develops and why age is a risk factor.

Aging and Cancer

Cancer is a complex disease with many factors at play, but it's ultimately caused by unorganized 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, a known cause of cancer. ^[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. However, your age is not the only determinant of your risk of colorectal cancer. It is also important to consider your family history, with up to 30% of people with colorectal cancer having a 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]} 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]

Identifying Signs of Colorectal Cancer at Any Age

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
• Blood in your stool
• Change in bowel habits lasting an extended period of time
• Fatigue
• Feeling like you need to have a bowel movement but can't
• Unexplained weight loss
• Rectal bleeding

Reducing Your Risk of Colorectal Cancer at Every Age

According to the American Cancer Society (ACS), 55% of all colorectal cancers are caused by 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.
• 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.

Additionally, screening for colorectal cancer is a crucial step to reducing your risk of colorectal cancer. Screening begins at age 45 for average-risk Americans who are currently not experiencing symptoms of colorectal cancer. 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^TM Liquid Biopsy: in-office blood test (Ask your healthcare provider how often to have this test)

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.

Screening for Colorectal Cancer With Everlywell

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.

References

1. Siegel RL, Torre LA, Soerjomataram I, et al. Global patterns and trends in colorectal cancer incidence in young adults. Gut. 2019;68(12):2179-2185. https://gut.bmj.com/content/68/12/2179
2. Colorectal cancer rising among young adults. National Cancer Institute. November 5, 2020. Accessed February 12, 2025. https://www.cancer.gov/news-events/cancer-currents-blog/2020/colorectal-cancer-rising-younger-adults
3. Siegel RL, Kratzer TB, Giaquinto AN, Sung H, Jemal A. Cancer statistics, 2025. CA Cancer J Clin. 2025;75(1):10-45. https://acsjournals.onlinelibrary.wiley.com/doi/10.3322/caac.21654
4. Colorectal Cancer Facts & Figures 2023-2025. American Cancer Society. Accessed February 9, 2025. https://www.cancer.org/research/cancer-facts-statistics/colorectal-cancer-facts-figures.html
5. Ullah F, Pillai AB, Omar N, Dima D, Harichand S. Early-Onset Colorectal Cancer: Current Insights. Cancers (Basel). 2023;15(12):3202. Published 2023 Jun 15. https://www.mdpi.com/2072-6694/15/12/3202
6. Sung H, Siegel RL, Laversanne M, et al. Colorectal cancer incidence trends in younger versus older adults: an analysis of population-based cancer registry data. Lancet Oncol. 2025;26(1):51-63. https://www.thelancet.com/journals/lanonc/article/PIIS1470-2045(24)00600-4/fulltext
7. Colorectal cancer risk factors. American Cancer Society. Accessed February 9, 2025. https://www.cancer.org/cancer/types/colon-rectal-cancer/causes-risks-prevention/risk-factors.html
8. US Preventive Services Task Force, Davidson KW, Barry MJ, et al. Screening for colorectal cancer: US Preventive Services Task Force recommendation statement: US preventive services task force recommendation statement. JAMA. 2021;325(19):1965-1977. https://jamanetwork.com/journals/jama/fullarticle/2779985
9. Mercadante AA, Kasi A. Genetics, cancer cell cycle phases. In: StatPearls. StatPearls Publishing; 2025. https://www.ncbi.nlm.nih.gov/books/NBK553159/
10. He M, Lo C, Wang K, et al. Immune-Mediated Diseases Associated With Cancer Risks. JAMA Oncol. 2022;8(2):209–219. https://jamanetwork.com/journals/jamaoncology/fullarticle/2786474
11. Weiss JM, Gupta S, Burke CA, et al. NCCN Guidelines® Insights: Genetic/Familial High-Risk Assessment: Colorectal, Version 1.2021. J Natl Compr Canc Netw. 2021;19(10):1122-1132. Published 2021 Oct 15. https://jnccn.org/view/journals/jnccn/19/10/article-p1122.xml
12. Causes of colorectal cancer. American Cancer Society. Accessed February 12, 2025. https://www.cancer.org/cancer/types/colon-rectal-cancer/causes-risks-prevention.html
13. Colorectal cancer signs and symptoms. American Cancer Society. Accessed February 12, 2025. https://www.cancer.org/cancer/types/colon-rectal-cancer/detection-diagnosis-staging/signs-and-symptoms.html
14. Rock CL, Thomson C, Gansler T, et al. American Cancer Society guideline for diet and physical activity for cancer prevention. CA Cancer J Clin. 2020;70(4):245-271. https://acsjournals.onlinelibrary.wiley.com/doi/full/10.3322/caac.21591
15. Guardant Health. ShieldTM Colorectal Cancer Screening Test Provider Brochure. Accessed February 9, 2025. https://www.guardanthealthamea.com/wp-content/uploads/Shield-Patient-Brochure-AMEA.pdf