It's not just your imagination: the data confirms it
Colorectal cancer remains, above all, a disease of older adults. The average age at diagnosis is 70, and most patients (more than 70%) are over 50 at the time of diagnosis. But within that overall picture, there’s a real shift: we mustn’t forget, however, that it can also occur in younger people, and the incidence is rising in this age group—those under 50.
The World Health Organization notes the same trend: it primarily affects people aged 50 and older, although in some places its incidence is rising among those aged 30 to 50. This is neither a perception nor a media fad: various Spanish research centers describe this trend as “the alarming rise in the incidence of early-onset colorectal cancer,” which they identify as an urgent research priority.
Why is this happening? What we know (and what we don’t yet know)
There is no single cause. The factors most frequently cited are dietary habits, genetic factors, tobacco, alcohol, and increased life expectancy, which together explain part of the rise in incidence observed in the general population. In studies focusing specifically on young patients, high consumption of processed meats and alcohol consumption also emerge as key factors, along with metabolic abnormalities detected in these patients’ blood tests.
There is an interesting line of research on the role of the environment: a team from the Vall d’Hebron Institute of Oncology has shown that certain environmental factors and lifestyle habits can leave a “footprint” on DNA that helps identify risk factors associated with colorectal cancer at a young age. It is also known that, although most colorectal cancers are not hereditary, the proportion of cases that are hereditary increases in the younger population, and one of the most significant hereditary causes is Lynch syndrome.
That said, be honest with yourself: as of today, there is no definitive answer to “why me.” Spain has specific projects underway, such as the TEOGIC study, dedicated to thoroughly characterizing early-onset gastrointestinal cancer in patients up to 50 years old, precisely because this phenomenon has not yet been studied in detail in our country.
Why Does It Take So Long to Diagnose Before Age 50?
If you feel like it took them a long time to take you seriously, you’re not alone. Between 70% and 95% of patients with early-onset colorectal cancer had previously experienced warning signs such as rectal bleeding, abdominal pain, changes in bowel habits, or anemia—and yet the diagnosis is still delayed. Part of the explanation is that these symptoms are often attributed to hemorrhoids, irritable bowel syndrome, or stress—both by the patient themselves and, at times, during the initial medical consultation.
This has clinical consequences: the high incidence of metastasis at diagnosis in patients under 50 could be explained by delayed diagnosis, a more aggressive tumor biology, or a combination of both. And there is another structural factor: people under 50 are usually excluded from screening programs, so, unlike someone who is 60, no one has offered them a preventive test before they develop symptoms.
The general warning signs of colorectal cancer are changes in bowel habits, abdominal pain, and rectal bleeding (bright red blood in the stool) or blood mixed with the stool. Sometimes the only sign is anemia caused by chronic bleeding, which may manifest as fatigue, shortness of breath, or palpitations. If you have persistent rectal bleeding, anemia with no clear cause, abdominal pain that doesn’t improve, or unintentional weight loss, talk to your healthcare team or go to your health center right away: this is not “normal” at any age.
Population-based screening didn’t include you—and that matters now
In Spain, the public colorectal cancer screening program targets men and women aged 50 to 69, with a fecal occult blood test every two years funded by the National Health System. In 2024, a decision was made to extend the upper age limit to 74, but the lower limit remains at 50: if you were diagnosed earlier, the standard screening program never invited you to participate.
This has direct implications for your family. If you have siblings, children, or parents, it’s important for them to know: when a first-degree relative has been diagnosed before age 50, the risk is considered higher than that of the general population, and guidelines recommend starting follow-up with colonoscopy before that age and more frequently than standard screening. Discuss this with your healthcare team so they can assess when and how to begin monitoring your family.
What they should specifically check for since you’re young
- Tumor testing (MSI/MMR): Anyone diagnosed with colorectal cancer before age 50 should undergo testing for microsatellite instability or mismatch repair (MSI/MMR) in the tumor, a recognized clinical criterion for suspecting Lynch syndrome. You can read more in our guide on MSI-H / dMMR.
- Genetic counseling: A diagnosis of colorectal cancer before age 50 is, in itself, a reason for you to be referred to a genetic counseling unit, where they will evaluate your family history and, if appropriate, perform a genetic blood test. If the result confirms a mutation, the risk of having inherited it or passing it on to children is 50% for each first-degree relative, which allows for timely screening of those who carry it. We have a comprehensive guide on Lynch syndrome that can help you understand the next steps.
- Detailed family history: Bring to your appointment information about which relatives have had cancer, what type, and at what age. This information is most helpful in determining whether genetic testing is necessary and what tests the rest of the family needs.
- Molecular panel (NGS): In advanced stages, a broad panel of biomarkers helps determine treatment, just as it does for older patients; being young doesn’t change this, but it’s important to make sure the test has been performed.
Things you have to think about that a 70-year-old doesn’t
A diagnosis before age 50 raises questions that go beyond medical concerns: fertility and chemotherapy, how to discuss this with young children, how to manage a mortgage or a job with a long-term leave of absence ahead, or how to apply for disability benefits if you need them. At crcwarriors.org, you’ll find specific guides on how to talk to children about cancer based on their age, taking time off work, permanent disability, and a map of financial and social assistance programs in Spain. You don’t have to figure it all out on your own—or all at once.
An Honest Message
The fact that colon cancer is on the rise among young people is a concerning and still poorly understood issue—it’s not your fault or the result of any specific habits you have: most young people diagnosed had no known family history of the disease. What you can control right now is making sure you get the right tests (MSI/MMR, genetic counseling if applicable) and that your family knows about your diagnosis so they can protect themselves through appropriate follow-up care. If at any time you feel that the reasons behind a decision aren’t being explained clearly to you, you have the right to request a second opinion within the public healthcare system.