Every year, doctors diagnose more than 107,000 cases of colorectal cancer. While survival rates have improved, it's still the second-leading cause of cancer deaths in men and women combined.
Knowing your risks and getting screened early can lead to a better outcome after a colon cancer diagnosis. Even so, most Americans are in the dark about how their lifestyle and other factors contribute to their risk. Nearly 80 percent of people don't know when to get a colonoscopy, and more than 90 percent can't identify colon cancer signs and symptoms.
To improve your odds of detecting this cancer early enough to effectively treat it, here are the facts behind eight common colon cancer myths.
1. Myth: Only Older People Get Colon Cancer
It's easy to see where at least part of this myth came from. The risk of getting a colon cancer diagnosis does increase as you get older (the average age at diagnosis is 66), but rates have been rising among millennials and Gen Zers.
“We've seen a growing, concerning trend of what we call early-onset colorectal cancer, meaning colorectal cancer being diagnosed in patients under the age of 50,” says Jun Gong, MD, an associate professor of medicine and medical director of the Colorectal Cancer Program at Cedars-Sinai in Los Angeles.
Today, about 1 in 10 people diagnosed with this cancer is younger than 50, and that number is rising each year. Up to 20 percent of people with young-onset colon cancer also have an inherited condition like Lynch syndrome that increases colon cancer risk. This shift in age is concerning, considering that early-onset colon cancers are often diagnosed at a more advanced stage than later-onset cancers.
2. Myth: You Can’t Prevent Colon Cancer
While no magic pill can guarantee a colon cancer–free future, timely screening goes a long way toward lowering the risk. Colon cancer is prevented when a colonoscopy finds precancerous polyps that are removed before they can turn into cancer. Experts estimate that up to 60 percent of deaths from colon cancer could be prevented if people followed screening recommendations.
Lifestyle changes are also protective. “There is growing evidence that exercise and diet can help prevent colon cancer, too,” says Dr. Gong. Cutting back on red and processed meats, avoiding alcohol and tobacco, getting regular aerobic exercise, and staying at a healthy weight are all effective preventive strategies.
3. Myth: If I Have a Healthy Lifestyle, I Won’t Get Colon Cancer
It's worth checking in with your parents, siblings, and children if you're not already familiar with their cancer history. People whose close relatives have colon cancer are nearly twice as likely to get the same diagnosis. Shared gene mutations, inherited syndromes, and common environmental exposures are some of the possible reasons why this cancer tends to run in families.
Whether you have one close relative with colon cancer or several, early screening is important when it's in your family tree. Your doctor might suggest starting colonoscopy screening even earlier than current guidelines recommend.
4. Myth: If I Had Colon Cancer, I Would Have Symptoms
Colon cancer may not cause any symptoms until it has spread. In a study of colorectal cancers detected through screening, up to 70 percent of people had no symptoms, even in people with advanced disease.
The often silent nature of this cancer makes early screening important. Testing can detect colon cancer before symptoms appear.
5. Myth: Screening Starts at Age 50
This was once true. Guidelines used to recommend colorectal cancer screening for adults starting at age 50, but the advice has changed.
Most organizations, including the American Cancer Society, the U.S. Preventive Services Task Force (USPSTF), and the American College of Gastroenterology (ACG), now suggest starting screening at age 45 for people who are at average risk for colon cancer. Screening at a younger age increases the chance that colon cancer will be found at an early stage, and reduces the risk of dying from this cancer.
6. Myth: Colonoscopy Is the Only Colon Cancer Screening Method
Colonoscopy is considered the “gold standard” screening test. That's because it's the most effective diagnostic method, identifying about 95 percent of colon cancers. During this test, which is recommended every 10 years for people at average risk, the doctor uses a long, flexible tube to see inside the colon and remove any polyps before they turn into cancer.
There are other options, though, including different types of visual exams (virtual colonoscopy and sigmoidoscopy) and stool- or blood-based tests. Screening frequency and effectiveness vary from test to test. For example, a flexible sigmoidoscopy is faster and requires less prep than a colonoscopy, but the scope only reaches the sigmoid colon (the lower part of the colon), so it can miss polyps in other parts of the colon. It’s also performed every five years if you’re at average risk, as opposed to 10.
The fecal immunochemical test (FIT) finds hidden blood in the stool, avoiding a procedure entirely. FIT is noninvasive, but it's less accurate than colonoscopy (it detects about 79 percent of these cancers) and it can't remove any polyps that are in the colon. “Patients need to understand that if [the test result is] positive, they will inevitably need a colonoscopy because that's the only definitive test,” says Gong.
7. Myth: Polyps Are Always Cancer
Not true. Polyps found in the colon are actually precancerous. “If you remove them, you essentially prevent the chance of the polyps becoming colon cancer,” says Gong. However, if you don't remove polyps, they can eventually develop into cancer.
8. Myth: Colon Cancer Isn't Curable
“If you are diagnosed with stage 1, 2, or 3 colon cancer, it is considered curable with surgery,” says Gong. About 90 percent of people whose colon cancer is caught at an early stage will still be alive five years later. Even once the cancer has spread outside the colon to nearby lymph nodes or other tissues, the five-year relative survival rate is more than 70 percent. Metastatic colon cancer that has spread to distant areas of the body isn't curable, but it is manageable with treatments.
The Takeaway
Colon cancer is typically diagnosed in older adults, but the incidence is rising among people under age 50.
New guidelines recommend starting screening at age 45.
Colonoscopy is the gold-standard for diagnosing colon cancer, but tests like flexible sigmoidoscopy and FIT are alternatives.
Following screening recommendations, along with lifestyle changes like a healthy diet and exercise, increases the chance of diagnosing colon cancer early, when it's most curable.
Everyday Health follows strict sourcing guidelines to ensure the accuracy of its content, outlined in our editorial policy. We use only trustworthy sources, including peer-reviewed studies, board-certified medical experts, patients with lived experience, and information from top institutions.
Colorectal Cancer Alliance State of Screening Study Reveals Potentially Fatal Attitudes & Misconceptions Among Americans. Colorectal Cancer Alliance. February 26, 2025.
MedStar Health Finds 79% of People Polled are Unaware of When to Get a Colonoscopy. MedStar Health. March 3, 2025.
Far PM et al. Quantitative Risk of Positive Family History in Developing Colorectal Cancer: A Meta-Analysis. World Journal of Gastroenterology. August 14, 2019.
What Are the Chances of Getting Colon Cancer If It Runs in Your Family? Moffitt Cancer Center.
Schult AL et al. Detection of Cancers and Advanced Adenomas in Asymptomatic Participants in Colorectal Cancer Screening: A Cross-Sectional Study. BMJ Open. July 1, 2021.
Do I Have Colorectal Cancer? Signs, Symptoms and Work-Up. American Cancer Society. February 8, 2021.
Daniel Landau, MD, is a distinguished board-certified hematologist-oncologist with a career that has spanned two eminent institutions: the Orlando Health Cancer Institute and the Medical University of South Carolina. With a specialized interest in genitourinary oncology and hematology, he has been at the forefront of managing both benign and malignant conditions.
Dr. Landau is a pioneering figure in integrating advanced technology into oncology, having served as a director of telemedicine services. Under his leadership, multiple innovative systems have been designed and piloted, all with a singular focus: enhancing the patient experience.
Beyond his clinical and technological endeavors, Landau is deeply committed to medical education. He has dedicated significant time and expertise to nurturing the skills of medical students, residents, and fellows, ensuring that the flame of knowledge and compassion burns bright in the next generation of oncologists.
Stephanie Watson is a freelance health writer who has contributed to WebMD, AARP.org, BabyCenter, Forbes Health, Fortune Well, Time, Self, Arthritis Today, Greatist, Healthgrades, and HealthCentral. Previously, she was the executive editor of Harvard Women’s Health Watch and Mount Sinai’s Focus on Healthy Aging. She has also written more than 30 young adult books on subjects ranging from celebrity biographies to brain injuries in football.
