Family history tied to nearly eightfold increased CRC risk for IBD patients
Patients with inflammatory bowel disease who have a first-degree relative with a history of colorectal cancer have a higher risk for also being diagnosed with that cancer, according to research published in Clinical Gastroenterology and Hepatology.
N. Jewel Samadder, MD, MSc, of the division of Gastroenterology and Hepatology at the Mayo Clinic in Phoenix, Arizona, and colleagues wrote that although risk for CRC among patients with IBD is already high, estimates of lifetime risk have varied. They sought to determine risk factors to help guide screening and surveillance strategies going forward.
“Family history of CRC in a first-degree relative is an important risk factor amongst those in the general healthy population, nearly doubling their risk of developing the disease,” they wrote. “Although there are increasing data to support the role of genetic susceptibility in the pathogenesis of IBD, little is known about the impact of family cancer history on development of CRC in IBD.”
Samadder and colleagues analyzed data from a cohort of patients with IBD from Utah between 1996 and 2011 (n = 9,505). They identified incidence of CRC and linked them to pedigrees using a population database and compared them with the state population by standardized incidence rates (SIR).
In the IBD cohort, 101 patients developed CRC during the study period. The SIR was increased in patients with both Crohn’s disease (3.4; 95% CI, 2.3–4.4) and ulcerative colitis (5.2; 95% CI, 3.9–6.6).
Investigators found that a family history of CRC in a first-degree relative was associated with a nearly eightfold increased risk for CRC in patients with IBD (7.9; 95% CI, 1.6–14.3). Additionally, patients with concomitant primary sclerosing cholangitis had the highest risk for CRC (14.8; 95% CI, 8.3–21.2).
Samadder and colleagues wrote that family history could be used as an important risk factor in patients with IBD and help clinicians determine screening and surveillance plans among these patients.
“The clinical implications of this study further quantify the risk of CRC in patients with IBD, the importance of obtaining a family history of CRC in these patients and ensuring these patients with a family history of CRC are informed and followed by intensive screening protocols,” they wrote. “This subset of IBD patients with a family history of CRC having a nearly 8-fold elevated risk of CRC would benefit from the aggressive screening strategies advocated by professional associations, including consideration for chromoendoscopy.” – by Alex Young
Disclosures: Samadder reports being a consultant for Cool Medical, Cancer Prevention Pharmaceuticals, and Janssen Research and Development.