Is Colorectal Cancer Rising in Young Adults?

Over the past two decades, reports have demonstrated a steady decrease of about 2.7 percent per year in new occurrence of colon and rectal cancers, despite an increase in the rate of obesity and meat consumption that have been linked to a greater risk of developing colorectal cancer.

Smoking is another factor that increases the risk of precancerous polyps and colorectal cancer. While the percentage of smokers decreased from 21 percent in 2005 to 17 percent in 2014, according to the Centers for Disease Control and Prevention, it's thought that much of the risk reduction in colorectal cancer is due to improved screening and surveillance of patients who are at risk.

[See: 8 Questions to Ask Your Doctor About Colon Cancer.]

Who is at risk of developing colorectal cancer?

Typically, at-risk patients are defined as individuals who are 50 years of age or older, although African-Americans are considered higher risk and can be screened earlier. Individuals with first-degree relatives diagnosed with colorectal cancer before the age of 60, or those with multiple second-degree relatives who had polyps or colon cancer, are traditionally also considered to be higher risk.

In 2017, a study published in JNCI: Journal of the National Cancer Institute, which used National Cancer Institute SEER registry data over 35 years, noticed a trend of increasing colorectal cancer rates in young adults ages 20 to 50. Additionally, the researchers predicted that by 2030, new cases will increase by 90 percent for colon cancer and 124 percent for rectal cancer in adults ages 20 to 34, with a smaller increase in those ages 35 to 49, of 28 percent and 46 percent, respectively.

What is the significance of the study's findings?

The trend is certainly worth keeping an eye on, but the incidence of colorectal cancer cases in young adults ages 20 to 50 is still small. With the size of the data that was evaluated, the study was sensitive enough to be able to detect small changes. In other words, this trend is small but may be real. Having said that, some cancer experts do predict that in the next two decades, up to 1 in 4 new cases of colorectal cancer may occur in younger age groups. It is not clear why this is happening.

While there is some speculation that obesity may be playing a role, there is no hard data to demonstrate correlation. Additionally, inflammatory bowel disease is increasing all around the world. When inflammatory bowel disease involves the colon, it can increase one's risk for colorectal cancer. This might also be part of the reason why colorectal cancers in young adults might be increasing.

[See: 10 Seemingly Innocent Symptoms You Shouldn't Ignore.]

What can young adults do?

The official medical professional societies haven't changed their colorectal cancer screening and surveillance guidelines based on the findings of this study. More studies are needed before those recommendations change.

For the individual, knowledge is key. When possible, it's important to understand your family history of colorectal cancer and other cancers. In addition, it's recommended to minimize factors that can increase the risk of developing colorectal cancer, such as excessive weight, high consumption of red meats and processed foods and smoking.

Studies have shown that taking a baby aspirin a day can reduce the risk of forming polyps when taken regularly for a long period of time. However, there is no data to suggest this will reduce cancer risk in young adults.

If you have an inflammatory bowel disease that involves your colon, work with your gastroenterologist to control the disease as quickly as possible and get colon cancer surveillance.

[See: Creative Ways Hospitals Reach Diverse Populations.]

Lastly, if you develop new symptoms such as a change in bowel movement or the feeling of a blockage, or rectal bleeding, it's important to let your doctor know. More evaluations may be warranted at that point.

In conclusion, it's important to be aware of the latest research findings and to understand their significance. Studies have reported a small increase in the incidence of colorectal cancer in people under age 50. If you're a young adult, focus on understanding your risks, minimizing them and alerting a health care provider if you develop symptoms.

Dr. Maged Rizk joined the Cleveland Clinic in 2008, with a particular interest in quality outcomes both on the medical and surgical arena. He served as Quality Improvement Officer for the Digestive Disease and Surgery Institute from 2010 to 2017. After earning his MBA from the University of Michigan Ross School of Business, Dr. Rizk became more involved in business development and strategy. He is the Vice Chair of Gastroenterology & Hepatology. His research focuses on quality metrics and quality in endoscopic procedures. Follow him on Twitter @MagedRizkMD.