Impact of family history on CRC risk decreases with age
Family history of colorectal cancer (CRC) in a first-degree relative (FDR) appears to confer a higher risk of CRC in younger vs older individuals, a study by the Chinese University of Hong Kong has shown.
The researchers analyzed data from 63 case-control/cohort studies that investigated the relationship between family history of CRC in FDRs and the prevalence of CRC. The studies, published between 1992 and 2016, included a total of 9.28 million individuals. [Am J Gastroenterol 2018, doi: 10.1038/s41395-018-0075-y]
A family history of CRC in FDRs conferred a significantly increased risk of CRC (relative risk [RR], 1.76; p<0.001). The increased risk was found to be higher in those <40 years vs those ≥40 years of age (RR, 3.29 vs 1.42; p=0.017), and in those <50 years vs those ≥50 years of age (RR, 2.81 vs 1/47; p=0.001).
Current CRC risk prediction algorithms assign a fixed score for family history of CRC regardless of age. Based on these findings, the researchers suggested that a higher score be assigned to positive family history for younger individuals, with the predictive capability of this approach to be assessed in future studies.