CRC risk with family history lower than previous estimates
Patients with first-degree family members who have been diagnosed with colorectal cancer are at lower risk than previously estimated for developing the disease themselves, according to recent study results.
“According to various clinical practice guidelines, individuals with [familial CRC] are recommended to undergo more intensive surveillance strategies than the general population, starting at an earlier age,” Rodrigo Jover, MD, PhD, of the department of gastroenterology at Hospital General Universitario de Alicante in Spain, and colleagues wrote. However, the definition of whom should undergo intensified colonoscopy surveillance instead of average-risk screening varies widely.”
Investigators searched the literature for case-control and cohort studies that explored the effect of family history on CRC risk. They calculated summary estimates of pooled relative risks using data from 42 case control studies and 20 cohort studies.
Jover and colleagues found that in case-control studies, the relative risk for CRC in patients with one first-degree relative was 1.92 (95% CI, 1.53–2.41), while the relative risk was 1.37 (95% CI, 0.76–2.46) in cohort studies. The researchers wrote that previous studies found a more than twofold increased risk for CRC among these patients. The cumulative risk for CRC at 85 years in this patient group was 4.8% (95% CI, 2.7%–8.3%).
Among patients with two first-degree relatives with a diagnosis, the relative risk for CRC was 2.81 in case-control studies (95% CI, 1.73–4.55) and 2.4 in cohort studies (95% CI, 1.76–3.28). The cumulative risk was 8.2% at 85 years (95% CI, 6.1%–10.9%).
In patients with a first-degree relative who was diagnosed with CRC before age 50 years, the relative risk for CRC was 3.57 in case-control studies (95% CI, 1.07–11.85) and 3.26 in cohort studies (95% CI, 2.82–3.77). The cumulative risk for CRC at 85 years was 11% (95% CI, 9.5%–12.4%).
“Our relative risk estimates and absolute risk estimates might be used to identify high risk groups in whom specific surveillance strategies aimed to prevent CRC could be considered,” Jover and colleagues wrote. “In contrast, the risk of developing CRC for individuals with a less extensive family history lead to lower risk estimates and for these individuals, average-risk screening programs might be considered as an optimal method for CRC prevention.” – by Alex Young
Disclosures: Jover reports receiving honorarium for consultancy from Alpha-Sigma, CPP Pharmaceuticals, GI Supply, MSD and Norgine. Please see the full study for all other authors’ relevant financial disclosures.