Experts have known for some time that family history is linked with a higher risk of colorectal cancer (CRC), including early-onset (before age 50) CRC. But the main risk was believed to be having a first-degree relative, such as a parent, child or sibling, with the disease.

Now there’s evidence that people with more distant relatives who have been diagnosed with CRC at a relatively young age may need to pay more attention to screening and prevention. Study findings published in the journal Cancer Epidemiology show that first-, second- and third-degree relatives of individuals with early-onset CRC face an elevated chance of developing the same illness at any age, reveals U.S. News & World Report.

Second-degree relatives include aunts, uncles, grandparents, grandchildren, nieces and nephews. Third-degree relatives include first cousins, great-grandparents and great-grandchildren.

For the study, a research team from the University at Buffalo and the University of Utah evaluated over 1,500 occurrences of early-onset colon cancer in the Utah Cancer Registry.

Scientists found that first-degree relatives of individuals diagnosed with early-onset CRC had six times the risk of developing the illness before age 50. Second- and third-degree family members had three times and 1.5 times the risk of developing colon cancer, respectively.

Results also showed that those with first-degree relatives with early-onset colon cancer faced 2.6 times the risk of developing the disease at any age. (The risk of developing the disease at any age for second- and third-degree family members was 1.96 and 1.3 times higher, respectively.)

“Our study provides new insight into the magnitude of risk for more distant relatives of colorectal cancer cases and in particular for relatives of cases who were diagnosed before age 50,” said Heather Ochs-Balcom, PhD, an associate professor of epidemiology and environmental health at the university’s School of Public Health and Health Professions. “The work is important given the rising rates of early-onset colorectal cancer.”

Researchers suggested that early screenings for CRC would be advantageous for first-, second- and third-degree relatives of people diagnosed with colorectal cancer before age 50.

To learn more about early colorectal screening, read “USPSTF: Screening for Colorectal Cancer Should Start at 45.” See also “Could the Western Diet Be a Risk Factor for Early-Age-Onset Colorectal Cancer?” and “How to Save a Life From Colorectal Cancer.