Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2000 Nov;83(10):1301-8.
doi: 10.1054/bjoc.2000.1407.

Prevalence and penetrance of BRCA1 and BRCA2 mutations in a population-based series of breast cancer cases. Anglian Breast Cancer Study Group

Anglian Breast Cancer Study Group  1
Affiliations

Prevalence and penetrance of BRCA1 and BRCA2 mutations in a population-based series of breast cancer cases. Anglian Breast Cancer Study Group

Anglian Breast Cancer Study Group. Br J Cancer. 2000 Nov.

Abstract

Estimates of the contribution of BRCA1 and BRCA2 to breast cancer incidence in outbred populations have been based on studies that are either small or have selected for cases diagnosed at an early age. Only one of these has reported an estimate of the breast cancer risk associated with a mutation in these genes, and there is no published ovarian cancer risk estimate derived from a population-based case series. We screened a population-based series of breast cancer cases diagnosed before the age of 55 for mutations in BRCA1 and BRCA2. Pedigree information from the mutation carriers was used to estimate penetrance and the proportion of familial risk of breast cancer due to BRCA1 and BRCA2. We identified eight (0.7%) BRCA1 and 16 (1.3%) BRCA2 mutation carriers in 1220 breast cancer cases (actual sample size 1435 adjusted for 15% polymerase chain reaction failure rate). Mutation prevalence was substantially higher in cases diagnosed before 35 years-of-age and with increasing number of relatives affected with breast or ovarian cancer. However, most mutation carriers were diagnosed in the older age groups, and a minority reported a first-degree relative with breast cancer. Breast cancer penetrance by age 80 was estimated to be 48% (95% CI 7-82%) for BRCA1 mutation carriers and 74% (7-94%) for BRCA2 mutation carriers. Ovarian cancer penetrance for BRCA1 and BRCA2 combined was 22% (6-65%) by age 80. 17% of the familial risk of breast cancer was attributable to BRCA1 and BRCA2. At birth, the estimated prevalence of BRCA1 mutation carriers was 0.07% or 0.09% depending on the penetrance function used for the calculation. For BRCA2, the birth prevalence estimates were 0.14% and 0.22%. Mutations in the genes BRCA1 and BRCA2 are rare in the population and account for a small fraction of all breast cancer in the UK. They account for less than one fifth of the familial risk of breast cancer. Eligibility criteria for BRCA1 and BRCA2 mutation testing based on family history and age of onset will identify only a small proportion of mutation carriers.

PubMed Disclaimer

Similar articles

See all similar articles

Cited by

See all "Cited by" articles

References

    1. Lancet. 1994 Mar 19;343(8899):692-5 - PubMed
    1. Int J Epidemiol. 1986 Mar;15(1):134-7 - PubMed
    1. Am J Hum Genet. 1995 Jan;56(1):265-71 - PubMed
    1. Nat Genet. 1995 Oct;11(2):198-200 - PubMed
    1. Am J Hum Genet. 1995 Dec;57(6):1457-62 - PubMed

Publication types