Colon Cancer in Young Adults: Know Your Risk

Timothy L. Cannon, MD, is a member of Inova Medical Group board certified in medical oncology and hematology. He has a special interest in managing of gastrointestinal cancers. Read Dr. Cannon’s profile.

March is Colorectal Cancer Awareness Month, and I always applaud efforts to raise awareness of this disease – the fourth most common cancer in the United States, and the second leading cause of cancer death.

Colorectal cancer awareness recently got an unexpected boost from a study published in the Journal of the National Cancer Institute, which found rates of the disease have been rising in young adults.

The article has gotten a lot of attention in the news. In fact, after reading about the study in the newspaper, an old childhood friend called me to discuss some symptoms he was having.

If you’re like my friend, you probably have questions about the increase in colon cancer among younger adults. Here’s what you need to know about this latest research.

Rising But Still Rare

The new study explored the rates of colorectal cancers from 1974 through 2013. During that period, rates of colon and rectal cancers declined in adults over 55. But rates of colon cancer and rectal cancer have increased significantly in adults in their 20s, 30s and 40s. That increase was sharpest among those in their 20s.

It’s important to keep in mind that while rates are rising, colorectal cancer is still quite rare in young adults. However, experts have been noticing this trend for some time. I’ve noticed it in my own practice, where I seem to be treating colorectal cancer in more men and women in their 20s and 30s.

It’s not entirely clear what’s behind the increase. Rising rates of obesity and diabetes are likely suspects. Changes in diet, in the environment and in people’s microbiomes (the population of bacteria in their guts) might also be factors.

The truth is, we don’t yet know the reason for the spike. But there’s a lot we do know about preventing and treating colorectal cancer.

Signs and Screenings

Common warning signs of colorectal cancer include changes in bowel habits, rectal bleeding with bright red blood and blood in the stool that can make the stool appear dark. Unfortunately, I’ve heard stories of younger patients who went to their doctor because of these symptoms and were told it was probably just hemorrhoids.

I think the most important takeaway from this study is that bleeding in the stool should always be taken seriously, no matter how young the patient is. Even in patients in their 20s or 30s, a colonoscopy may be warranted depending on their symptoms.

Similarly, women who have low iron levels are often told it’s probably related to heavy periods. That is often the case, but I would advise such women to check their stool to make sure it’s not black or bloody, and maybe even to be tested for occult bleeding in the stool.

The good news is that it takes years for pre-cancerous polyps to develop into full-blown colorectal cancer, and colonoscopies are good at detecting signs of a problem early on. If you have symptoms, don’t put off seeing your doctor.