Colon Cancer Screening Now Starts at 45: Why Early Detection Matters More Than Ever

March is Colon Cancer Awareness Month, and this year’s message is especially important: colon cancer is increasingly affecting younger adults. Because of this concerning trend, routine colon cancer screening now begins at age 45 instead of 50 for average-risk individuals.

Many people still remember when screening started at 50. That recommendation has changed. Today, both men and women should begin colorectal cancer screening at age 45.

Here’s what you need to know.

Why Was the Colon Cancer Screening Age Lowered to 45?

In recent years, multiple national organizations — including the American Cancer Society — updated their guidelines to recommend starting colorectal cancer screening at age 45.

The reason was clear: colon cancer rates have been steadily rising in adults under 50.

While screening has successfully reduced colorectal cancer rates in older adults, cases in people in their 30s and 40s have increased. Even more concerning, younger patients are often diagnosed at later stages, when treatment becomes more complex and less successful.

Lowering the screening age allows physicians to detect precancerous polyps and early-stage colon cancer sooner — when outcomes are significantly better.

Colon Cancer in Younger Adults: A Growing Concern

Recent data shows a striking shift:

• Colorectal cancer is now the #1 cause of cancer-related death in men under age 50

• It is the #2 cause of cancer-related death in women under age 50

Each year in the United States, more than 150,000 new cases of colorectal cancer are diagnosed.

Although screening has helped reduce overall mortality, the rise in younger individuals is real. This is exactly why starting colon cancer screening at age 45 is so important.

Why Is Colon Cancer Increasing in People Under 50?

Researchers are still working to fully understand this trend, but likely contributing factors include:

• Increased consumption of processed and ultra-processed foods

• Sedentary lifestyles

• Rising obesity rates

• Lower dietary fiber intake

Emerging research also suggests changes in the gut microbiome may influence colorectal cancer risk.

Importantly, many younger patients diagnosed with colon cancer have no obvious risk factors — which is why screening and symptom awareness are critical.

Colon Cancer Can Affect Healthy, Active Individuals

Public awareness has grown in part due to high-profile cases.

Actor James Van Der Beek has spoken publicly about colon cancer, and Chadwick Boseman — star of Black Panther — passed away from colon cancer at age 43.

These cases underscore an important reality: colon cancer does not only affect older adults.

Why Colonoscopy Is the Gold Standard for Colon Cancer Screening

There are multiple screening options available, but colonoscopy remains the most comprehensive test because it both detects and prevents cancer.

During a colonoscopy:

• The entire colon is examined

• Precancerous polyps can be identified

• Polyps can be removed during the same procedure

• Early cancers can be detected before symptoms develop

When colon cancer is diagnosed at Stage I, survival rates exceed 90%. When detected later, outcomes decline significantly.

Because early colon cancer often causes no symptoms, screening at the recommended age is essential — even if you feel completely healthy.

When Should You Get a Colonoscopy?

Average Risk Individuals

If you are a 45-year-old man or woman with no symptoms and no family history of colon cancer, you should begin routine screening at age 45. The interval for repeat testing depends on your results and your physician’s recommendation.

Higher-Risk Patients

You may need screening earlier than 45 if you have:

• A family history of colon cancer or advanced polyps

• A personal history of inflammatory bowel disease

• A hereditary colorectal cancer syndrome

In many cases, screening begins 10 years before the youngest affected family member’s diagnosis.

Colon Cancer Symptoms That Should Never Be Ignored

Regardless of age, seek evaluation from a gastroenterologist if you experience:

• Rectal bleeding

• Persistent changes in bowel habits

• Iron deficiency anemia

• Unexplained weight loss

• Ongoing abdominal pain

• New or persistent constipation or diarrhea

You are never “too young” to have concerning symptoms evaluated.

The Importance of Colon Cancer Awareness Month

Colon cancer is:

• One of the most common cancers in the United States

• Increasing in younger adults

• Often preventable through screening

• Highly treatable when detected early

The decision to lower the screening age to 45 reflects real data and real lives affected.

If you are 45 or older and have not yet scheduled your colon cancer screening, now is the time.

If you are younger and experiencing symptoms, do not delay evaluation.

Early detection saves lives. Colonoscopy prevents cancer. And starting at age 45, screening should be part of your routine healthcare.