Risk Of Pediatric Malignancy In Families Known To Carry Brca1/2 Mutations

1535Background: Inherited mutations in cancer predisposition genes typically associated with adult-onset cancers, including BRCA1/2, have been found in children with cancer. However, it is unknown whether such mutations are causative. Our objective is to determine whether there is an increased risk of pediatric malignancy in families known to carry BRCA1/2 mutations. Methods: We utilized the Cancer Risk Evaluation Program (CREP), a registry of high-risk breast and ovarian cancer families undergoing BRCA1/2 testing. We compared the proportion of pediatric malignancies (age ≤ 18 years) among families tested positive vs negative for BRCA1/2 mutations in 1) the proband’s siblings and 2) other potential at risk relatives of the proband (siblings, children, nieces and nephews). We used generalized estimating equations to account for familial clustering. We compared pediatric malignancy rates in BRCA1/2 mutation positive families from CREP to the general population from SEER (Surveillance, Epidemiology and End-R...