Why Are More Young Adults Getting Colon Cancer? What You Should Know

Colon Cancer Isn’t Just an “Older Adult” Disease Anymore

A new and alarming trend is reshaping the conversation around colon cancer: more young adults—some as young as their late teens—are being diagnosed with the disease. Just a few decades ago, the average age of a colorectal cancer diagnosis was 72. Today, that number has dropped to 67, with many cases now appearing in people under 50.

Why is this happening—and what can you do to protect yourself?

What Is Early-Onset Colorectal Cancer?

Early-onset colorectal cancer is defined as colorectal cancer diagnosed in someone under age 50. It now accounts for nearly 1 in 5 new colorectal cancer cases in the U.S., according to the American Cancer Society. The disease is also now the leading cause of cancer death in men under 50 and the second leading cause in women.

This shift is causing concern among oncologists and researchers alike, as the causes behind this increase are still not fully understood.

Possible Reasons for the Rise in Young Adult Cases

While genetics can play a role, most of these early-onset cases are not linked to inherited conditions like Lynch syndrome. Instead, researchers point to a range of possible contributors:

• Sedentary lifestyle
• Obesity and poor diet (especially low fiber, high red meat intake)
• Alcohol and tobacco use
• Environmental exposures, such as microplastics
• Disruption of the gut microbiome
• Unknown biological or birth cohort effects

There is no one single condition or lifestyle to attribute to the increase in colon cancer but the trend is concerning nonetheless.

Red Flag Symptoms to Never Ignore

One of the most dangerous parts of this trend is that younger adults often dismiss warning signs or delay seeing a doctor—thinking cancer isn’t possible at their age. This can lead to late-stage diagnoses that are harder to treat.

Here are symptoms you shouldn’t ignore:

• Rectal bleeding or blood in your stool
• Changes in bowel habits (constipation or diarrhea lasting 2+ weeks)
• Unexplained weight loss
• Persistent fatigue or anemia
• Abdominal pain or cramping
• Feeling of fullness quickly when eating

Even if you think it's just a "stomach ache" or "lactose intolerance," it’s worth going to your primary care provider to rule out cancer.

When to Get Screened for Colon Cancer

In response to the rise in cases among younger adults, major health organizations—including the U.S. Preventive Services Task Force—now recommend that routine colorectal cancer screening begin at age 45.

You may need earlier screening if:

• You have a family history of colorectal cancer or polyps
• You have inflammatory bowel disease (IBD)
• You’re experiencing persistent gastrointestinal symptoms

A colonoscopy remains the gold standard for screening because it can detect and remove precancerous polyps before they become dangerous.

💡 If you’re unsure whether you need screening, talk to your primary care provider at BASS Medical Group.

What If You’re Diagnosed?

Colon cancer is treatable, especially when caught early. Treatment may include:

• Surgery to remove tumors
• Chemotherapy and radiation, depending on stage and location
• Immunotherapy, especially in patients with Lynch syndrome or MSI-H tumors

For younger patients, treatment often includes counseling, mental health support, and long-term care planning.

At BASS Medical Group, our providers work closely with patients to coordinate personalized, whole-person cancer care, whether it’s through surgery, imaging, genetics, or survivorship support.

What Young Adults Can Do Right Now

Even if you feel healthy, you can take steps today to reduce your risk:

• Eat more fiber: Aim for 25 grams/day from fruits, vegetables, whole grains, and legumes
• Quit smoking and limit alcohol
• Move more: Exercise regularly to reduce inflammation and maintain a healthy weight
• Listen to your body and report any GI symptoms early‍
• Know your family history and talk to your doctor about it

Schedule a Screening. Protect Your Future.

If you're under 50 and experiencing symptoms—or over 45 and due for a routine screening—don’t wait. Early detection can save your life. BASS Medical Group offers expert colonoscopy referrals, genetic testing guidance, and supportive care throughout Northern California. If you're diagnosed with colorectal cancer, our specialists in the Colon & Rectal Surgery department and the Gregory Rhodes MD Cancer Center are here to provide advanced, compassionate treatment every step of the way.

Request an appointment or call your local BASS office to speak with a provider today.

Sources & Credits

Portions of this article were adapted from “As Rates of Some Cancers Increase in Younger People, Researchers Search for Answers” originally published by the National Cancer Institute. The National Cancer Institute does not endorse this adaptation and no endorsement should be inferred.