Colon cancer cases have more than doubled in young people since 1999, new research shows

• Cancer rates in people under 45 have surged over the past two decades, researchers found.
• Diagnoses are increasing most rapidly in teens and people in their early 20s.

New evidence shows how sharply colon cancer rates are skyrocketing in people younger than 45.

A team of researchers led by Dr. Islam Mohamed, a physician at the University of Missouri-Kansas City, analyzed CDC data on colon cancer incidence in Americans aged 10 to 44 over two decades.

They found that cases have more than tripled in teenagers and more than doubled for people in their early 20s.

While the biggest jump in cancer diagnoses was in younger people, the surge in cancer rates was significant across all age groups under 45:

• Late 20s to early 30s: The rate of people diagnosed with colon cancer in this age range increased about 70% from 1999 to 2020.
• Late 30s: For this age group, the rate increased 58% in the same time period.
• Early 40s: This demographic had the highest overall rate. Cancer cases increased by 45% for people in their early 40s from 1999 to 2020.

The study will be presented at Digestive Disease Week, a meeting for professionals in gastroenterology and related fields, from May 18 to 21 in Washington, D.C.

The findings suggest a need for better awareness, treatment, and prevention options for younger people.

"Colorectal cancer is no longer considered just a disease of the elderly population," Mohamed said in a press release. "It's important that the public is aware of signs and symptoms of colorectal cancer."

Colon cancer signs to look out for

Regular testing can be particularly important for colon cancer because symptoms can be hard to recognize until more advanced stages of the disease.

The most common early warning signs of colon cancer include abdominal pain, rectal bleeding, anemia (iron deficiency), and changes to bathroom habits (like diarrhea or constipation), according to Mohamed.

While the increase is striking, overall numbers of colon cancer diagnoses in young people are still low. In 2020, there were 1.3 cases per 100,000 teenagers and 2 cases per 100,000 people in their early 20s.

As a result, colonoscopy screening is only recommended for people older than 45, according to the CDC.

Strategies to prevent colon cancer

One potentially preventable risk factor behind the rising cancer rates is diet, as some evidence suggests that consuming more processed foods and added sugar are linked to greater odds of developing cancer.

Strategies to reduce your risk of colon cancer include eating enough fiber and avoiding tobacco and alcohol. Regular exercise has also been linked to a lower risk of multiple types of cancer.

However, colon cancer risk can also be genetic. Ongoing research is investigating whether the gut microbiome, bacteria in the digestive system, may play a role in colon cancer and if potential risk factors could include food additives or some antibiotics that disrupt microbes in the gut.