You Need To Know These Signs of Colon Cancer in Younger Adults

Woman having painful stomach ache.

Some of the symptoms are easy to “brush away” — but you shouldn’t.

Colon cancer is a scourge, and as you know, early detection is a subject very close to Katie’s heart. Increasingly, younger patients are being diagnosed.

According to the American Cancer Society, the proportion of cases occurring in people under age 55 doubled from between 1995 and 2019, so it’s critical that we’re vigilant for symptoms earlier than ever. As we’ve covered before, major medical associations like the American Cancer Society and United Services Preventive Services Task Force have updated their guidelines to recommend regular screening start at age 45, five years earlier than previous recommendations.  A 2020 study even suggested that beginning some form of screening from the age of 40 could be cost-effective.

Keep a lookout for telltale signs — even before you hit screening age

Even with these more rigorous guidelines in place, it’s so worth keeping on the lookout for signs of colon cancer that may be in evidence even before your screening comes up.

“It can be difficult or embarrassing to talk about,” Dr. Matthew Kalady, the director of the division of colon and rectal surgery at the Ohio State University Comprehensive Cancer Center told NBC News. “But the reality is everybody deals with something like this,” and it’s important to understand what’s normal and what’s not, he said.

According to new research from Washington University School of Medicine in St. Louis published in the Journal of the National Cancer Institute, four early signs of colon cancer to watch for are:

  • Abdominal pain.
  • Rectal bleeding.
  • Ongoing diarrhea.
  • Iron deficiency anemia, which is usually picked up in yearly blood tests.

The study included 5,075 people with early-onset colorectal cancer. Nearly half of the participants had at least one of the above symptoms three months before they received their diagnosis — and in some cases, they showed signs two years before.

Don’t let the warning signs slide

Some of these symptoms are the kind of thing it’s easy to “brush away” as patients, said Dr. Cassandra Fritz, an author of the study. But they “should alarm you.”

It’s so worth catching colon cancer in its early stages. Research indicates that if caught in time while the cancer is still localized, the five-year survival rate is roughly 90%. 

A rising threat for younger generations

According to a 2017 study published in the Journal of the National Cancer Institute, people born after 1990 are twice as likely to be diagnosed with colon cancer, and four times as likely to get rectal cancer versus people born in 1950.

Though certain lifestyle factors — eg being more sedentary — may be linked to an increased risk, the reality is that the science behind why there’s been such a drastic uptick in younger people isn’t yet clear. Even young people who lead what we think of as super-healthy lifestyles (say, by eating diets rich in vegetables and fruits) are proving susceptible to the disease.

“It isn’t just diet and lifestyle, there is something else,” Dr. Kimmie Ng, director of the Young-Onset Colorectal Cancer Center at the Dana Farber Cancer Institute, said in an interview.

Factors like very high alcohol consumption are linked to an increase risk for colon cancer in older patients, but this and other lifestyle factors (like excess consumption of red meat) aren’t enough to explain the rising trend in younger patients.

“If you have excess body weight, you are at a higher risk of colorectal cancer in your 40s than someone who is average weight,” Rebecca Siegel, a cancer epidemiologist and senior scientific director of surveillance research at the American Cancer Society told CNN. “But the excess risk is pretty small. So again, that is probably not what’s driving this increase, and it’s another reason to think that there’s something else going on.”

While some cases can be explained due to genetics and family history, NBC News notes that an incredible 75% of cases of colon cancer in younger people are categorized as having an “unknown cause.”

According to Dr. Folasade P. May, an associate professor of medicine at the University of California who spoke to NBC News, this indicates that environmental factors shared by this age group are driving the increase — what’s known as the “birth cohort effect.” These could include anything from stress to exposure to pollutants, but the jury’s still out on what they are.