Younger than 50? Don’t rule out colorectal cancer

By Nicole Brudos Ferrara

Regular screening with colonoscopies and lower rates of smoking have reduced colorectal cancer rates in older adults. But for those under 50 in the U.S., cancers of the colon and rectum are now a leading cause of cancer death, according to the National Cancer Institute.

"The vast majority of patients who get colon cancer are going to be above the age of 50," says Jeremy Jones, M.D., a Mayo Clinic medical oncologist. "But the amount of those patients has declined as we've gotten better at screening. We've seen a trend in the opposite direction for younger patients — about a 50% relative increase in the percentage of patients under 50 who have been diagnosed with colon cancer."

No one is too young to get colorectal cancer, according to Dr. Jones. "We have to get the word out that these cancers are becoming more commonplace in younger patients. We cannot as a medical community ignore these signs and symptoms," he says.

Here's what everyone should know about the rise of colorectal cancer diagnoses in younger people:

Researchers don't yet know why more people under 50 are developing colorectal cancer.

Health care professionals don't know what's causing the increase in colorectal cancer rates among younger people. Some speculate that it may be related to an increase in risk factors for colorectal cancer among this age group, such as obesity, a lack of exercise and an unhealthy diet.

Dr. Jones believes the cause is more complex. "I see a lot of patients who are not overweight or obese who have developed colon cancer," he says. "A lot of smart people are researching this. Anytime we've been looking at something for four or five years and we haven't been able to figure it out, that tells me it's probably a number of different things. It's likely genetic plus microbiome plus all of these other things combined that are leading to this increase."
Health care professionals have identified several factors that may increase your risk of colorectal cancer, including:

  • Being older than 50.
  • Being African American.
  • Having a personal history of colorectal cancer or polyps.
  • Having inflammatory intestinal conditions, such as ulcerative colitis and Crohn's disease.
  • Having an inherited syndrome that increases colon cancer risk, such as familial adenomatous polyposis and Lynch syndrome.
  • Having a family history of colorectal cancer.
  • Eating a low-fiber, high-fat diet.
  • Living a sedentary lifestyle.
  • Having diabetes.
  • Being overweight or obese.
  • Smoking.
  • Using alcohol heavily.
  • Having had radiation therapy directed at the abdomen to treat previous cancers.

However, you can have all these risk factors and never develop colorectal cancer. You also can develop colorectal cancer without having had any of these risk factors.

"For any individual patient, a risk factor is just a risk factor. It's not a certainty that you will develop cancer," says Dr. Jones.

Colorectal cancer screening is now recommended for everyone, starting at age 45.

Screening for colorectal cancer is now recommended for all people, beginning at age 45 rather than 50. The U.S. Preventive Services Task Force recently updated its guidelines to begin screening five years earlier, citing a comparative modeling study that found colorectal cancer screening demonstrates a benefit for people at age 45.

"I'm biased because I see these patients in clinic, but I think 45 is probably not young enough. My goal for the future is to harness some of the newer, less-invasive technologies, such as stool DNA tests or blood-based screening tests, to catch these patients who are 30, 40 or even 20," says Dr. Jones.

Dr. Jones strongly recommends everyone consider screening for colorectal cancer at age 45. If you have a personal or family history of the disease, you should talk to your health care professional to determine if you need to begin screening before age 45.

"If your parents developed colon cancer at the age of 50, generally, we would start screening about 10 years before that," says Dr. Jones. "If you have a family history of a syndromic type of colorectal cancer, such as familial adenomatous polyposis, which is very high risk, we might start screening at the age of 10, 15 or 20. With Lynch syndrome, if nobody in the family has had cancer until age 35, then maybe we start at 30."

Young people and their health care professionals should take signs and symptoms of colorectal cancer seriously.

"One of the fundamental problems we run into with early onset colon cancer is that these patients are not captured early," says Dr. Jones. "If you're over the age of 50, you're far more likely to have been diagnosed early because you had a colonoscopy and it was removed at stage 1 or stage 2. That is far more important in terms of prognosis and survival than anything else we end up doing for you."

Younger people who develop colorectal cancer are less likely to be diagnosed at an early stage of the disease because many people experience no symptoms at that stage. When symptoms appear, they'll likely vary, depending on the cancer's size and location in the large intestine.

Signs and symptoms of colorectal cancer include:

  • A persistent change in your bowel habits, including diarrhea or constipation, or a change in the consistency of your stool.
  • Rectal bleeding or blood in your stool.
  • Persistent abdominal discomfort, such as cramps, gas or pain.
  • A feeling that your bowel doesn't empty completely.
  • Weakness or fatigue.
  • Unexplained weight loss.

If you experience any of these symptoms, talk to your health care professional, and insist that colorectal cancer be ruled out.

"I see patients at least once a week who say: 'I had blood in my stool. I told my doctor, and they said you're too young to have cancer. It's probably hemorrhoids.' Or I had unexplained abdominal pain or unexplained weight loss, and I was told that 'I was too young to have colon cancer,'" says Dr. Jones. "I 100% agree that hemorrhoids are more common than colon cancer, but you have to rule those out. You have to prove that it's not cancer."

Learn more

To hear Dr. Jones discuss his experience treating patients younger than 50 for colorectal cancer, watch this video:

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