No evidence of increased breast cancer risk for proven noncarriers from BRCA1 and BRCA2 families.

In families screened for mutations in the BRCA1 or BRCA2 genes and found to have a segregating mutation the breast cancer risk for women shown not to carry the family-specific mutation might be at above "average" risk. We assessed the risk of breast cancer in a clinic based cohort of 725 female proven noncarriers in 239 BRCA1 and BRCA2 families compared with birth-matched controls from the Danish Civil Registration System. Prospective analysis showed no significantly increased risk for breast cancer in noncarriers with a hazard ratio of 0.67 [95 % confidence interval (CI) 0.32-1.42, p = 0.29] for all family members who tested negative and 0.87 (95 % CI 0.38-1.97, p = 0.73) for non-carries who were first-degree relatives of mutation carriers. Proven noncarriers from BRCA1 and BRCA2 families have no markedly increased risk for breast cancer compared to the general population, and our data do not suggest targeted breast cancer surveillance for noncarriers from BRCA1 and BRCA2 families.

Familial cancer. 2016 Oct [Epub]

Henriette Roed Nielsen, Janne Petersen, Lotte Krogh, Mef Nilbert, Anne-Bine Skytte

Department of Clinical Genetics, Vejle Hospital, Kabbeltoft 25, 7100, Vejle, Denmark. This email address is being protected from spambots. You need JavaScript enabled to view it.., HNPCC Register, Clinical Research Center, Copenhagen University Hospital, Hvidovre, Denmark., Department of Clinical Genetics, Odense University Hospital, Odense, Denmark., Department of Clinical Genetics, Aarhus University Hospital, Aarhus, Denmark.