Abstract 161P
Background
Female CHEK2 c.1100delC carriers are eligible for additional breast surveillance due to an increased breast cancer risk. Increased risks for other cancers have been reported. We studied whether CHEK2 c.1100delC is associated with an increased risk for other types of cancer within these families.
Methods
Including 10,780 individuals from 609 CHEK2 c.1100delC families, we calculated standardized incidence rates (SIRs) and absolute excess risk (AER, per 10.000 person years) by comparing first-reported cancer derived from the pedigrees with general Dutch population rates from 1970 onwards. Attained-age analyses were performed for sites where significant increased risks were found.
Results
We found significant increased risks of colorectal cancer (CRC; SIR=1.43, 95%CI=1.14-1.76; AER=1.43 in women and SIR=1.47; 95%CI=1.22-1.77; AER=2.25 in men) and hematological cancers in women (SIR=1.32; 95%CI=1.02-1.67; AER=0.87). CRC was significantly more frequent in CHEK2 families from age 45 onwards.
Conclusions
A significantly increased risk of CRC, and hematological cancers in women was found, starting at a younger age than expected. Currently, colorectal surveillance starts at age 45 in high-risk individuals, independent of CHEK2 status. Our results suggest that some CHEK2 families might benefit from this surveillance as well, however, further research is needed to determine who may profit from this additional colorectal surveillance.
Legal entity responsible for the study
The authors.
Funding
Dutch Cancer Society.
Disclosure
All authors have declared no conflicts of interest.