US Incidence of Colorectal Cancer Increases Among Youth

23 Jan 2015 --- The incidence of colorectal cancer (CRC) among young adults ages 20-39 years has increased during the past 20-30 years, despite declining rates of CRC for the U.S. population overall.

Colorectal cancer is the cancer that is most attributed to diet and lifestyle. Previous studies have found that people who have a diet high in red meat and processed foods are more likely to suffer from the disease, although the exact mechanisms are unclear. It could be the increased carcinogens in the form of nitrates in processed meat products, which is now widely thought to be the contributing factor. Low intake of fibre-rich foods and fruit & vegetables are also thought to be an important contributing factor.

This surprising new finding, an analysis of how CRC incidence varies based on race and gender, and differences in tumor location, for young adults compared to the general population are presented in Journal of Adolescent and Young Adult Oncology (JAYAO.

In the article "Colorectal Cancer Incidence Among Young Adults in California," Kathryn Singh, MPH, MS, Thomas Taylor, PhD, Chuan-Ju Pan, MD, Michael Stamos, MD, and Jason Zell, DO, MPH, University of California, Irvine, analyzed more than 231,500 CRC cases over a 22-year period, including 5,617 cases affecting young adults. 

CRC is uncommon in people younger than 50 years of age. Among older adults, screening to detect and remove precancerous polyps has largely contributed to declining CRC rates for the U.S. population as a whole. Across the study period, however, the authors found significant increases in CRC incidence among the 20-29 year and 30-39 year age groups. The data also showed greater CRC risk for certain racial groups, and differences in tumor location and stage at diagnosis for young adults compared to individuals 50 years of age and older.