Burden of early-onset colorectal cancer incidence has been underestimated, study shows

A study analyzing LSU Health's Louisiana Tumor Registry and other NCI-designated tumor registry data found that by the time recommended screening for colorectal begins, cancers have already spread in a high percentage of people. Results report that the rate of colorectal cancer incidence increased by 46.1% from 49 to 50 years of age (the age recommended to start routine colorectal cancer screening) and that 92.9% of the cases of colorectal cancer diagnosed at age 50 were invasive (localized, regional or distant stage.) The study is published in JAMA Network Open.

The findings of this study indicate that the burden of early-onset of colorectal cancer incidence for 45-49-year olds has been underestimated because asymptomatic colorectal cancers were not detected due to lack of screening."

Xiao-Cheng Wu, M.D., Professor and Director of the Louisiana Tumor Registry at LSU Health New Orleans School of Public Health

Data from the National Cancer Institute's Surveillance, Epidemiology & End Results (SEER) 18 registries, representing 28% of the U.S. population, were used to conduct a cross-sectional study of colorectal cancer incidence rates from January 1, 2000, to December 31, 2015, in 1-year age increments (ages 30-60 years) stratified by US region (South, West, Northeast and Midwest), sex, race, disease stage, and tumor location. Statistical analysis was conducted from November 1, 2018, to December 15, 2019. LSU Health New Orleans' Louisiana Tumor Registry is one of the 18 SEER registries. The research team, led by Dr. Jordan Karlitz of the Southeast Louisiana Veterans Health Care System and Tulane University, along with LSU Health New Orleans Louisiana Tumor Registry staff, analyzed a total of 170,434 cases of colorectal cancer. They found steep increases in the incidence of colorectal cancers from 49 to 50 years of age.

The U.S. Preventive Services Task Force recommends screening beginning at age 50.

"As the diagnosis of many of these colorectal cancers was delayed to ages after 50, advanced stage was more likely present at diagnosis," adds Dr. Wu. "This study provides useful evidence for improving colorectal cancer screening policy."