A team from Stockholm, Sweden, and Boston, Massachusetts, assessed the significance of familial colorectal cancer (CRC), or inflammatory bowel disease (IBD), on the risk for CRC in patients with IBD.
19,876 individuals with ulcerative colitis or Crohn's disease born between 1941 and 1995 were enrolled into the population-based cohort study.
|Family history of colorectal cancer could identify IBD patients at increased risk.
A registry-based follow-up was used to assess familial CRC, and IBD incidence. Risk of CRC was assessed as incidence proportion (absolute risk) and relative risk.
Familial CRC was found to be associated with a more than 2-fold risk of CRC (adjusted relative risk = 2.5). It was also associated with an increase in the incidence proportion of CRC, at 54 years of age, from 3.8% to 6.9%.
The researchers found that patients with a first-degree relative diagnosed with CRC before 50 years of age had a higher relative risk (9.2) and the highest incidence proportion (29%).
No association with familial IBD was observed.
Johan Askling, of the Karolinska Institutet, Stockholm, concluded on behalf of the group, "Information on family history of CRC may be a simple way to identify individuals with IBD at elevated risk of developing colorectal cancer."