Colon cancer is the third most common cancer in the United States, with about 106,000 new cases diagnosed each year

Colon cancer affects roughly 1 in 23 men and 1 in 25 women over a lifetime. The actual number of diagnoses varies year to year—some years see slightly higher counts, others slightly lower—but the overall trend has been relatively stable for the past decade. What has changed is the age at which people are diagnosed: colon cancer rates in people under 50 have been rising, even as rates in older adults have fallen.

These numbers come from the National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) program, which tracks cancer cases across the United States. SEER data shows that colon cancer remains serious enough to warrant regular screening, but common enough that understanding your risk factors and screening options matters for most adults.

Key Takeaways

  • About 106,000 new colon cancer cases are diagnosed in the United States each year, making it the third most common cancer overall.
  • Your lifetime risk of developing colon cancer is roughly 1 in 23 if you are a man and 1 in 25 if you are a woman.
  • Colon cancer rates in people under 50 have been rising over the past two decades, while rates in older adults have declined.
  • Age, family history, inflammatory bowel disease, and certain genetic conditions significantly increase your risk.
  • Regular screening starting at age 45 (or earlier if you have risk factors) can detect cancer early when treatment is most effective.

Who is most likely to develop colon cancer

Age is the strongest risk factor. Most colon cancers occur in people over 50, with the average age at diagnosis around 68. However, the rising rates in younger adults mean colon cancer is no longer rare in people in their 30s and 40s.

Family history matters significantly. If a parent, sibling, or child had colon cancer, your risk is higher—especially if they were diagnosed before age 50. People with a parent who had colon cancer have roughly double the risk compared to those with no family history. If multiple relatives had it, or if relatives had it at a young age, your risk rises further.

Certain inherited genetic conditions dramatically increase risk. Lynch syndrome (also called hereditary nonpolyposis colorectal cancer, or HNPCC) accounts for 2 to 4 percent of all colon cancers. People with Lynch syndrome have a 70 to 80 percent lifetime risk of developing colon cancer. Familial adenomatous polyposis (FAP) is rarer but nearly guarantees colon cancer by age 40 if untreated, because people with FAP develop hundreds or thousands of polyps in the colon.

Inflammatory bowel disease—specifically Crohn's disease and ulcerative colitis—increases colon cancer risk. People with these conditions have roughly 2 to 8 times the risk of developing colon cancer compared to the general population, depending on how long they have had the disease and how much of the colon is affected.

How colon cancer rates have changed over time

Overall colon cancer rates have declined in people over 65 since the 1990s, largely because screening with colonoscopy has become more common and catches cancers early or prevents them entirely by removing polyps. This is one of the clearest examples of how screening saves lives.

The picture is different in younger adults. Colon cancer rates in people under 50 have been rising by roughly 1 to 2 percent per year since the 1990s. Researchers are still investigating why. Possible factors include higher obesity rates, changes in diet, less physical activity, and differences in the microbiome—but no single cause has been identified. This trend is why major health organizations now recommend screening starting at age 45 instead of 50, a change made in 2021 by the American Cancer Society.

Differences in colon cancer rates by race and ethnicity

Colon cancer rates are not evenly distributed across racial and ethnic groups. Black Americans have the highest incidence rate and the highest mortality rate from colon cancer. Black men are diagnosed at a rate of about 52 per 100,000 people per year, compared to about 40 per 100,000 for white men. Black women are diagnosed at a rate of about 40 per 100,000 compared to about 33 per 100,000 for white women.

These differences reflect a combination of factors: later-stage diagnosis (meaning cancer is found after it has spread), lower screening rates, differences in access to treatment, and possibly biological differences in how the cancer behaves. American Indian and Alaska Native populations also have higher rates than white populations. Hispanic and Asian American populations generally have lower rates, though rates vary within these broad categories.

Addressing these disparities is a focus of cancer research and public health efforts, because the differences are not due to biology alone but to barriers in screening access and quality of care.

What the statistics mean for your screening decisions

The fact that colon cancer is the third most common cancer does not mean you will develop it. It means the disease is common enough that screening is worthwhile for most adults. The American Cancer Society recommends screening starting at age 45 for people at average risk. If you have a family history of colon cancer, a personal history of inflammatory bowel disease, or a genetic condition that increases risk, screening may start earlier—sometimes in your 20s or 30s.

Screening methods include colonoscopy (which allows doctors to see the entire colon and remove polyps), flexible sigmoidoscopy (which examines the lower part of the colon), fecal immunochemical testing (a stool test), and CT colonography (a CT scan of the colon). Each has different intervals—colonoscopy is typically done every 10 years if normal, while stool tests are usually annual. Your doctor can help you choose based on your risk factors and preferences.

Survival rates and early detection

Colon cancer survival depends heavily on the stage at diagnosis. When colon cancer is caught at stage 1 (before it spreads beyond the colon wall), the five-year survival rate is about 90 percent. At stage 2, it drops to about 70 percent. At stage 3, it is about 50 percent. At stage 4 (when cancer has spread to distant organs), it is about 10 percent.

This is why screening matters: colonoscopy can find cancer at stage 1 or even prevent it by removing precancerous polyps. Most colon cancers develop from polyps over 10 to 15 years, giving screening time to work. People who are screened regularly are more likely to have cancer detected early, when treatment is most effective.

Frequently Asked Questions

What is my actual risk of getting colon cancer?

Your lifetime risk depends on your age, family history, and other factors. The average person has about a 1 in 23 to 1 in 25 risk, but this varies. If you have a parent with colon cancer, your risk roughly doubles. If you have Lynch syndrome, your risk is 70 to 80 percent. Talk to your doctor about your specific risk based on your health history.

Why are colon cancer rates rising in younger people?

Researchers do not yet have a definitive answer. Possible factors include higher obesity rates, dietary changes, less physical activity, and shifts in gut bacteria. The trend is real and consistent, which is why screening now starts at 45 instead of 50 for average-risk adults.

Does having a family member with colon cancer mean I will get it?

No. Family history increases your risk, but it does not may provide you will develop colon cancer. If a parent had it, your risk is roughly double the average, but most people with family history never develop the disease. Screening starting earlier can catch cancer if it does develop.

Are some races more likely to die from colon cancer?

Black Americans have higher colon cancer rates and higher mortality rates than other groups. This reflects differences in screening access, timing of diagnosis, and quality of care—not biological differences. Addressing these disparities is an ongoing focus of public health efforts.

Can screening prevent colon cancer?

Yes, in a sense. Colonoscopy can remove polyps before they become cancer, preventing the disease from developing. This is why regular screening is so effective at reducing colon cancer deaths in screened populations.