The relationship between inflammatory bowel disease (IBD) and the incidence and mortality of colorectal adenocarcinoma has not been evaluated recently.
Dr Lisa Herrinton and colleagues from California, USA calculated the incidence and standardized incidence and mortality rate ratios of colorectal cancer among adult individuals with intact colons using Kaiser Permanente of Northern California's database of members with IBD and general membership data for the period of 1998 to 2010.
The research team also evaluated trends in medication use and rates of cancer detection over time.
The team identified 29 cancers among persons with Crohn's disease and 53 among persons with ulcerative colitis.
|Standardized mortality ratio for colorectal cancer in Crohn's was 2|
Overall, the incidence rates of cancer among individuals with Crohn's disease, ulcerative colitis, or in the general membership were 75, 76, and 47, respectively, per 100,000 person-years.
In the general population, the incidence of colorectal cancer was 21% higher in 2007–2010 than in 1998–2001, coincident with the growth of colorectal cancer screening programs.
The incidence of colorectal cancer among individuals with Crohn's disease or ulcerative colitis was 60% higher than in the general population, and was stable over time.
During 1998–2008, the standardized mortality ratio for colorectal cancer in individuals with Crohn's disease was 2, and 2 in those with ulcerative colitis.
Over the study period, anti–tumor necrosis factor agents replaced other therapies for Crohn's disease and ulcerative colitis.
The rate of colonoscopy increased by 33% among patients with Crohn's disease and decreased by 9% in those with ulcerative colitis.
Dr Herrinton's team concludes, "From 1998 to 2010, the incidence of colorectal cancer in patients with IBD was 60% higher than in the general population and essentially stable over time."