The face of colorectal cancer is changing. Today, incidence rates of colon and rectal cancer are increasing among adults under 50. The Young-Onset Colorectal Cancer Center at Dana-Farber is addressing the unique challenges facing this younger age group.
According to a 2026 study from the American Cancer Society, incidence is rising among young adults by 3% in people ages 20 to 49 even though incidence overall has declined modestly. One 2023 study predicts colon cancer will increase by 30% for young adults by 2030.
Why are colon and rectal cancers on the rise in young adults?
Researchers are still trying to determine the reason for the trend, according to Marios Giannakis, MD, PhD, an oncologist and researcher at the Center for Gastrointestinal Oncology at the Dana-Farber Cancer Institute.
Researchers do not believe that increased incidence is due primarily to our inherited DNA, as the human genome does not evolve quickly. Instead, they are exploring many other possibilities, including lifestyle habits, obesity, the microbiome, or recent environmental exposures — the chemicals and compounds we encounter daily.
“What’s important to know is that colon and rectal cancers aren’t diseases just for older adults anymore,” explains Giannakis. “It’s vital for everyone to listen to their bodies and not ignore any symptoms, as well as adhere to the screening guidelines.”
What are the signs and symptoms of colorectal cancer?
The signs and symptoms of colon and rectal cancer vary and depend on a variety of factors including tumor size and location. Many people — particularly those with polyps or early stages of colorectal cancer — may not experience any signs or symptoms, making the disease difficult to detect outside screening.
Symptoms that are persistent (lasting longer than a few days), or getting progressively worse, should be evaluated by a medical professional. Symptoms may include:
- A change in bowel habits
- Blood (either bright red or very dark) in the stool
- Diarrhea, constipation, or feeling that the bowel does not empty all the way
- Stools that are narrower than usual
- Persistent bloating, gas pains, fullness, or cramps
- Unintentional weight loss
- Feeling very tired
- Vomiting
- Anemia (low red blood cell count)
These signs and symptoms can have many non-cancerous causes. Consult with your physician if symptoms persist.
Are colorectal cancer symptoms the same regardless of age?
Yes, colorectal cancer typically has the same symptoms regardless of a person’s age.
Oftentimes, young-onset colorectal cancer is originally misdiagnosed or overlooked by both patients and doctors. If something doesn’t feel right or symptoms persist, seek a second opinion.
Should I get a colonoscopy?
The American Cancer Society recommends regular colorectal cancer screenings beginning at age 45 for most adults. These guidelines were updated in May 2018 due to the rise in young-onset colorectal cancer.
What can I do to lower my risk of colorectal cancer?
Researchers are still working to understand the risk factors for colorectal cancer. Aside from paying attention to symptoms and screening, maintaining a healthy lifestyle may help reduce risk.
This includes:
- Exercising regularly.
- Limiting alcohol, processed meat, and animal fat intake.
- Eating a diet high in fruits, vegetables, and whole grains.
Do colorectal cancer treatments vary based on the patient’s age?
While the standard of care is generally similar across age groups, treatment plans are tailored to each patient’s age, health, and individual needs.
Learn more on what you should know about colon cancer and your risk.
What should I be aware of as a young colorectal cancer patient?
A colorectal cancer diagnosis can be overwhelming at any age, but those diagnosed before 50 face a unique set of challenges. The Young-Onset Colorectal Cancer Center at the Dana-Farber Cancer Institute, one of the first centers in the country dedicated to young patients with colorectal cancer, offers a variety of programs designed to address everything from fertility concerns to sexual health and psychological support.
Remember that you are not alone. If you feel it would be beneficial, ask your oncologist about available support groups.
What research is being done to study young-onset colorectal cancer?
Multiple efforts are underway to learn more about the causes of young-onset colorectal cancer, and how doctors can more effectively treat it. At Dana-Farber, researchers are working to characterize the unique genomic, molecular, and immune features of this disease to better understand factors that may put someone at a higher risk of developing colon cancer.
This research also aims to identify new and effective interventions for both prevention and treatment.
“Other recent research has discovered that the microbiome in young adults differs from older adults. Particularly, there appears to be lower bacterial diversity in the gut among the younger population,” Giannakis says. “Our gut health is incredibly important to study, because our gut can lead us in the direction to unlock the reason for the change in incidence in this age group.”
Notably, the mutations caused by a DNA-damaging toxin called colibactin, made by certain bacteria in the gut like a particular strain of E. coli, has a strong link to the rise in early-onset colon cancer. Colibactin exposure may stem from early in life and trigger mutations prior to when symptoms develop. “Not all young individuals’ colorectal cancers have the colibactin signature, but it is a risk factor that is being heavily researched,” Giannakis says.
Examples of ongoing work at Dana-Farber include:
- The Living Biobank: Tumor tissue and other specimens are collected from patients and healthy volunteers to help determine the most promising new treatments for testing in clinical trials.
- Laboratory models of cancer: Laboratory models are created to mimic the human tumor and study the efficacy of new therapies to target the cancer cells, the immune system, and the microbiome.
- Microbiome research: Made up of trillions of microorganisms, the microbiome is important to gut health. Researchers are working to explore the differences between a healthy microbiome and one associated with colorectal cancer as well as how the microbiome may impact treatment efficacy and toxicity. By doing so, they hope to uncover how it may play a role in the tumor’s development and ensuing therapies.
- Screening and early detection research: Ongoing efforts include introducing non-invasive tests to better identify individuals who are at a higher risk of colon cancer and would benefit from early disease screening.
There are many clinical trials available to patients diagnosed with young-onset colorectal cancer. If you’d like to learn more about available trials, contact your care team.
About the Medical Reviewer
Dr. Giannakis received his undergraduate degree from the University of Toronto in 2001 and his medical and doctoral degrees from Washington University School of Medicine in 2009. He subsequently completed his Internal Medicine residency at Brigham and Women’s Hospital and his fellowship in Medical Oncology and Hematology at Dana-Farber Cancer Institute.
Dr. Giannakis is a medical oncologist and clinical investigator at the Dana-Farber Gastrointestinal Cancer Center. He also conducts research at Dana-Farber and the Broad Institute of MIT and Harvard to understand the molecular mechanisms of colorectal cancer formation and develop novel targeted and immune-based treatments for gastrointestinal cancers.
Very helpful and timely article, Mario.