March is Colorectal Cancer Awareness Month, and doctors and health advocates are sounding the alarm over a worrying trend: more and more younger Americans are being diagnosed with the disease. Even more troubling, many of the cases are at an advanced stage, confusing doctors.
The colon and rectum are part of the large intestine. Colon cancer, formerly known as colon cancer (CRC), typically begins when a mutation occurs that leads to abnormal cell growth. This can lead to the formation of colon polyps, which the Mayo Clinic defines as small clumps of cells that form on the lining of the colon. In the early stages, these polyps can be benign, but over time they can become cancerous. This type of cancer is known to primarily affect older adults, but it is increasingly being seen in younger people around the world.
The alarming increase in colon cancer diagnoses among young people was highlighted in a recent report by the American Cancer Society. Rates among Americans under the age of 55 have nearly doubled, according to the study, from 11% in 1995 to 20% in 2019. Some studies estimate that the disease is the leading cause of cancer deaths in the United States in people ages 20 to 49 years could be up to the year 2040.
Of even greater concern to physicians, however, is that late-stage diagnoses are also rising sharply in young patients. According to the report, “60% of all new cases in 2019 were advanced, up from 52% in the mid-2000s.”
To better understand why this is happening, Yahoo News spoke to Dr. Marios Giannakis, a medical oncologist and clinical researcher at the Young-Onset Colorectal Cancer Center, part of the Dana-Farber Cancer Institute in Boston. The center cares for patients with early-onset colon cancer and also conducts multidisciplinary research to better understand the disease and develop ways to prevent, detect and treat it.
Why is colon cancer on the rise in young people?
“This epidemic of early-onset colorectal cancer is fairly new and largely unexplained,” Giannakis told Yahoo News.
He explained that early onset CRC has some unique characteristics. It tends to be more aggressive and often occurs on the left side of the colon rather than the right, and some patients with this type of cancer experience abdominal pain or rectal bleeding. However, he noted that many patients may not have any symptoms.
Why CRC cases are increasing in people under 50 is a puzzling question that remains unanswered, and one Giannakis said: this underscores the need for ongoing research. But There is some evidence as to why this may be happening.
Experts believe that lifestyle risk factors may contribute to the increase in early onset CRC rates. Younger Americans are more likely to be obese and lead more sedentary lives. They also consume larger amounts of processed and sugary foods, according to experts. All of these factors are known to increase the risk of developing colon cancer.
According to the American Cancer Society, 55% of all CRCs are linked to lifestyle factors. However, the organization notes that the strongest risk factor for developing the disease is a family history.
Environmental stresses have also been linked to CRC at a young age, Giannakis said.
“One of the thoughts that has followed the epidemiological trends of this phenomenon since the 1990s is what is called the birth cohort effect,” he said. “Essentially what this means is that a risk factor, or maybe a combination of risk factors, in the environment is only transmitted to younger generations because younger generations are simply more exposed to it,” he added.
But Giannakis said lifestyle and environmental factors don’t tell the whole story.
“Could be other things that we don’t fully understand in terms of the molecular types of cancer, the cancer types themselves, but also the microenvironment of cancer, [or] what surrounds these early-onset tumors,” he said.
Research into the microbiome – a community of microorganisms, mainly bacteria, found throughout the human body, particularly the gut – is one of the research areas Giannakis’ team is focusing on. He said one question they hope to answer is “whether the microbiome in our gut is changing in ways that favor colon cancer.”
According to the Dana-Farber Cancer Institute, recent studies have found that these bacteria may play a role in the development of CRCs and also in their response to treatments.
In a new article published in Science and co-authored by Giannakis, researchers at the Dana-Farber Cancer Institute outlined the type of studies needed to better understand the underlying causes and biology of early-onset CRC. This research, the authors say, should address a combination of factors such as genetics, environmental and lifestyle factors, people’s immune systems, and the environment in which these cancers grow.
Where in the US are more colon cancers diagnosed in younger people?
A recent study from the Cleveland Clinic sheds light on where young-age CRC cases and deaths appear to be more common in the United States
“Among the youngest patients, we found notable hotspots in the Midwest and also in the Great Lakes region,” said Blake Buchalter, a Cleveland Clinic researcher and lead author of the study, in a statement. In addition to finding these hotspots, the research team located three locations where colon cancer is less common at a young age: the Southwest, California and the Mountain West region.
Researchers said it’s unclear why colon cancer is more common among young people in certain areas of the country, but they plan further research to find answers.
But we do know who in the population is at higher risk. Based on new data from the American Cancer Society, three groups in the US population — Native American, Alaskan Native and Black Americans — are disproportionately affected by the disease and have the highest rates of diagnoses and deaths of any group in the country.
How can people reduce their risk of colon cancer?
The Centers for Disease Control and Prevention say the most effective way to reduce a person’s risk of colon cancer is to get routine screening. The age at which an average-risk person should be screened has been lowered from 50 to 45 in 2021. Some people, e.g. however, individuals with a family history of CRC and Black Americans should consider doing so sooner. The American College of Physicians recommends that black men and women have their first screening at age 40.
The gold standard for colon cancer screening, Giannakis said, is a colonoscopy. The test can show where polyps are located in the colon, and doctors can remove most of these and some cancers during the procedure. However, most people under the age of 45 are not eligible for a colonoscopy, so experts believe lowering the screening age may be necessary in the future to detect cancer in people in their 20s or 30s.
In addition to a colonoscopy, there are other types of screening tests in the United States. The CDC recommends consulting a doctor to determine which one is best for you.
To lower your risk of CRC, the agency recommends eating a healthy diet “low in animal fats and high in fruits, vegetables, and whole grains.” Also, increasing physical activity, maintaining a healthy weight, and reducing alcohol consumption and smoking can reduce a person’s risk of developing this type of cancer.
Finally, Giannakis said young people should not ignore the symptoms associated with the disease. These may include changes in bowel habits, blood in the stool, abdominal pain, and weight loss.
“It’s important to listen to our bodies, even at a young age, when we have symptoms that indicate cancer. However, as we recognize that many of these cancers are asymptomatic, we should also remain committed to screening and follow up on that,” he said.
Originally published